1981-1991 yamaha srv540 snowmobiles (1)

1981 SR540E

SECTION INDEX

GENERAL

ENGINE

CARBURETION

POWER TRAIN

CHASSIS

ELECTRICAL

APPENDIX RACING TIPS

1981 SR540E

CHAPTER 1. GENERAL

1-1. EXTERNAL VIEW .......................................................................................................... 1-2

1-2. MACHINE IDENTIFiCATION ...................................................................................... 1-3

A. Frame serial number ............................................................................................ 1-3

B. Engine serial number ........................................................................................... 1-3

1-3. MAINTENANCE INTERVALS CHARTS .................................................................... 1-4

A. Periodic maintenance .......................................................................................... 1-4

B. Lubrication intervals ............................................................................................ 1-5

1-4. HIGH ALTITUDE TUNING .......................................................................................... 1-5

1981 SR540E

CHAPTER 1. GENERAL

1-1. EXTERNAL VIEW

1-2

1-2. MACHINE IDENTIFICATION

A. Frame serial number The frame serial number is located on the righthand side of frame (just below the front of seat). The first three digits identify the model. This is followed by a dash. The remaining digits identify the production number of the unit.

Frame starting serial number 8L9-016101

1-3. MAINTENANCE INTERVALS CHARTS

A. Periodic maintenance

1981 SR540E

B. Engine serial number The engine serial number is located on the fan case. The prefix indicates engine type and displacement. The prefix is followed by a dash and the serial number. Normally both frame and engine serial numbers are identical.

Engine starting serial number SA535-016101

(Use this just as guide only. Certain conditions may require more frequent inspection of components.)

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally

400km 800km 1.600km necessary (250mi) (500mi) (1.000mi)

ENGINE:

Tightness of bolts and nuts 0 0

Bends. cracks and wear 0 0

Abnormal noise 0 0

Loose connection and breaks of fuel and pulse pipes 0 0

Loose connection and breaks of oil pipes 0 0

Loose connection and breaks of oil delivery pipe 0 0

Fan belt tension/cracks/damage 0 0

Manual rope starter system 0 0

Carburetor

• Operation of starter jet 0 0

• Mixing adjuster (pilot screw) 0 0

• Idling speed adjustment 0 0 .. ,,_.

Operation and adjustment of oil pump 0 0

Ignition timing 0

Cylinder compressions 0 0

Cylinder head/exhaust pipe decarbonize 0

Spark plug condition. gap and cleaning 0 0

Tightening of the cylinder head •• 0

1-3

1981 SR540E

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally

400km 800km 1.600 km necessary (250mi) (500mi) (1.000mi)

DRIVE:

Tightness of bolts and nuts 0 0

Wear on slide runners 0 0

Primary drive system 0 0

V-belt 0 0

Secondary drive system 0 0

Sheave distance 0 0

Sheave offset 0 0

8rake pad wear 0 0

Brake operation and adjustment 0 0

Guide wheel rubber 0 0

Wear of drive track wheel sprocket 0 0

Drive track adjustment 0 0

Breaks in drive track 0 0

Bends in front and rear axles 0 0

Checking of lock washers 0 0

Drive chain adjustment 0 0

Drive chain oil level ' 0 0

CHASSIS:

Tightness of bolts a nd nuts 0 0

Bends and cracks 0 0

Welded riveted. joints 0 0

Ski adjustment 0 0

Ski runner wear 0 0

Breaks in fuel tank 0 0

Cleaning of fuel tank 0

Fuel filter 0

Loose connection and breaks in fuel pipe 0 0

Breaks in oil tank 0 0

Oil filter 0

ELECTRICAL:

Wear. breakage of wire covering 0 0

Breaks in high-tension cord 0 0

Voltage regulator working voltage 0

Operation of engine stop switch 0 0

Operation of tether switch 0 0

Headlight 0 0

Taillight 0 0

Brake light 0 0

•• Retighten every 10 hours from the first use.

1-4

1981 SR540E

B. Lubrication intervals

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or When . Seasonally Oil/Grease

400km 800km 1.600km necessary Brand name (250mi) (500 mil (1.000 mil

ENGINE:

Starter case 0

Oil pump contr~1 box 0 0 Aeroshell grease #7 A or Esso Beacon 325 grease

Pump drive cover 0 0

Oil in the oil tank 0 YAMAlUBE 2-cycle oil

DRIVE:

Primary sheave weight 0 0

and roller pins Molybdenum disulfide

Secondary shaft and 0 0

snowmobile grease

Sliding sheave

Front axle housing 0 0

Shaft 1 and shaft 2 0 0

light all-purpose grease

(Slide rail)

Drive chain oil 0 0 Gear oil API "Gl-3"

replacement SAE #75 or #80

BODY:

Steering column lower 0 0 light all-purpose grease

bearing

Steering column upper 0 0 Motor oil bearing

Steering links 0 0

Ski column 0 0 light all-purpose grease

Ski retaining pin 0 0 light all-purpose grease

Brake cable end stopper 0 0 Esso Beacon 325 grease and brake lever

Telescopic strut suspension r>

1-5

1981 SR540E

1-4. HIGH ALTITUDE TUNING

To attain the best machine performance to match high altitude condition. the snowmobile must be properly set. The tuning should be done as follows.

J Test main jet size

(performance & plug colour! Not OK (Page 3-3)

I OK

Confirm STD settings

.Carburetor (Page 3·21

.Ignition timing (Page 6-31

• Spark plug (Page 6-61

1 Adjust main Jet size according to the chart

(Page 3-41

Adjust main jet size

~ I I

L-____ !Te_s_t_lo_w_s_p_e_e_d_s_et_ti_n_g __ ,-~~I··--------~~ ______________ -J~K ~ I

Not OK

Not OK OK

Try high altitude settings

Not OK

Decide if problem is slow jet

and adjust accordingly

Not OK

OK

OK

Not OK

Check to see if gearing is too high or low

OK Not OK

• Adjust gearing as reqUired

(Page 4-131

I OK

Check engagement speed and

shift performance

Not OK OK

Adjust primary clutch as required

(Page 4-4)

Not OK OK

I Not OK

High altitude

tUning O. K.

Adjust secondary clutch as required

(Page 4-91 OK

'-6

1981 SR540E

CHAPTER 2. ENGINE

2-1. DiSASSEMBLy ............................................................................................................. 2-2

A. Engine removal ..................................................................................................... 2-2

B. Starter ..................................................................................................................... 2-2

C. Cooling fan ............................................................................................................ 2-3

D. Flywheel magneto ................................................................................................ 2-3

E. Oil pump ................................................................................................................ 2-4

F. Engine disassembly ............................................................................................. 2-5

2-2. INSPECTION, REASSEMBLY AND ADJUSTMENT .............................................. 2-6

A. Engine component ............................................................................................... 2-6

B. Oil pump .............................................................................................................. 2-12

C. Flywheel magneto ............................................................................................. 2-14

D. Cooling fan .......................................................................................................... 2-15

E. Starter. ................................................................................................................. 2-18

F.. Engine remounting ............................................................................................ 2-19

1981 SR540E

CHAPTER 2. ·ENGINE

2-1. DISASSEMBLY

A. Engine removal Remove the engine by removing the following parts.

NOTE:----------------------~

It is not necessary to remove the engine to remove the following parts: • Cylinder head • Cylinder • Piston • Autolube pump • Manual starter assembly • Cooling fan • Flywheel magneto • Carburetor • Intake reed valve

Snowmobile

V-belt

Primary sheave (Refer to "4-1- B. Primary-sheave")

Carburetor (Refer to "3-1-B. Carburetor Overhauling)

Muffler

Fuel pipe

Oil pipe

Pulse pipe

Tachometer cable

Magneto lead wire

Manual starter handle

Shroud stopper

2-2

Engine mounting nuts

Engine

B. Starter 1. Remove starter assembly from the fan

case .

2. Remove the drive plate mounting nut at its center, and remove the drive plate.

3. There is a drive plate spring and a drive pawl under the drive plate.

NOTE:------------------------~

Take care so that they are not lost.

1. Drive plate spring 2. Drive pawl

3. Return spring

4. Remove the sheave drum.

CAUTION: -----------. There is a starter spring (coiled) under the sheave drum. Care should be taken so that it will not spring out.

5. To remove the starter rope. undo the knot on one end of the rope. Then pull it out from the starter case.

C. Cooling fan 1. Remove the fan case cap.

2. Using the rotor holding tool. remove the three bolts. and remove the starter pulley.

Tool name Tool No.

Rotor holding tool 90890-01235

2-3

1981 SR540E

1. Rotor holding tool

3. Remove the drive fan pulley and fan belt.

4. Remove the fan case assembly.

5. Remove the driven fan pulley securing nut. spring washer. plate washer. fan pulley. key. and washers (shims).

NOTE:------------------------Take care so that the key and washers (shims) are not lost.

1981 SR540E

6. Remove the cooling fan assembly by tapping the fan shaft.

D. Flywheel magneto 1. Using the rotor holder tool. remove the

flywheel mounting nut.

Tool name Tool No.

Rotor holding tool 90890-01235

1. Rotor holding tool

2. Using the flywheel puller. remove the flywheel assembly.

2-4

No. Tool name Tool No.

1 Drive handle 90890-01817

2 Flywheel puller bolt 90890-01803

3 Flywheel puller body 90890-01848

4 Flywheel puller screw 90890-01806 (4)8 X 80 mm)

5 Flywheel puller 90890-01804 attachment

NOTE:------------------------When removing the flywheel. the key must be removed from the crankshaft. Take care so that it is not lost.

3. Remove Phillips-head screw. and remove the coil plate.

E. Oil pump 1. Remove the oil delivery pipes. 2. Remove the bolts and pump drive case.

NOTE:------------------------The oil pump can be removed as an assemb~ Iy together with the pump drive cover. If it is hard to remove the pump drive case. tap it with a soft-faced hammer.

CAUTION:------------------~

The oil pump must not be disassembled, because the oil pump is a precision work.

3. Remove oil pump cap and pump wire. 4. Remove oil pump assembly.

F. Engine disassembly 1. Remove the air shroud. 2. Remove the intake manifold and reed

valves.

NOTE:------------------____ ___ For reed valve inspection. refer to 3-2 Reed valve.

2-5

1981 SR540E

3. Remove the exhaust pipe assembly. 4. Remove the cylinder head holding nuts.

cylinder head and gasket.

NOTE:-------------------------Loosen spark plugs before removing cylinder head.

5. Remove the cylinder holding nuts. cylinder and cylinder base gasket.

6. Remove piston pin clip from piston.

NOTE:-----------------------Before removing the piston pin clip. cover the crankcase with a clean rag to prevent the clip from accidentally falling into the crankcase.

7. Push piston pin. from opposite side. then pull out. Protect pin with rag.

NOTE:-------------------------Before moving piston pin. deburr clip groove and pin hole area.

8. Remove engine brackets. 9. Remove crankcase holding bolts. Each

bolt position is numbered. Start with the largest number for disassembly. Loosen each bolt 1/4 turns and proceed to the next.

1981 SR540E

10. Split crankcase by lightly striking the upper and lower crankcases.

11. Remove crankshaft by tapping the shaft with your hands.

2-2. INSPECTION, REASSEMBLY AND ADJUSTMENT

A. Engine components 1. Crankcase a. Thoroughly wash the case halves in

mild solvent. b. Clean gasket matching surfaces and

crankcase matching surfaces thoroughly.

c. Visually inspect case halves for any cracks, road damage, etc.

d. Check oil delivery passages in transfer. ports for signs of blockage.

2. Bearing and oil seal inspection a. After cleaning and lubricating bearings,

rotate outer race with a finger. If rough spots are noticed, replace the bearing.

b. Check oil seal lips for damage and wear. Replace as required.

3. Bearing and oil seal installation a. When installing or removisng left crank

oil seal and bearing, remove the pump drive gear and install the new drive gear.

2-6

CAUTION: ---------....., When removing pump drive gear, replace it with new one.

b. Install bearing(s) with . their manufacturer's marks or numbers facing outward. (In other words, the stamped letters must be on the. exposed to view side.)

c. Install oil seal(s) with their manufacturer's marks or numbers facing outward.

d. When installing bearing(s) or oil seal(s). apply the specified lUbrication.

Crank bearing Yamalube 2-cycle oil

Crankshaft oil seal Low temperature grease (Esso Beacon 325 or

lip Aeroshell grease #7 Al

4. Crankshaft inspection a. Check connection rod axial play at small

end. (to determine the amount of wear of crank pin and bearing at big end). If small end play exceeds tolerance, disassemble the crankshaft, check connecting rod, crank pin and big end bearing. Replace defective parts. Play after reassembly should be within specification.

Road axial play: Maximum 2.0 mm (0.079 in)

b. Check the connecting rod side clearance at big end. If axial play exceeds tolerance. disassemble the crankshaft and replace any worn parts. Big end axial play should be within specification.

Rod side clearance

Minimum Maximum

0.25 iTlm (0.010 in) 0.75 mm (0.030 in)

c. Check crankshaft assembly runout (misalignmentof crankshaft parts). Dial gauge readings should be within specification. Correct any misalignment by tapping the flywheel with a brass hammer and/or by using a wedge.

Deflection tolerance

Left side Center Center Right side (left) (right)

0.03 mm 0.04mm 0.04mm 0.05mm (0.0012 in) (0.0016 in) (0.0016 in) (0.0020 in)

2-7

1981 SR540E

5. Crankshaft installation a. Install the circlip half on crank bearing

as illustrated. (The primary sheave side.)

LOWER CASE

UPPER CASE

.1. Circlip 2. Sealing surface 3. Knock-pin

b. Install the crankshaft assembly with oil seal. align the bearing punch marks with the crankcase lower and upper matching surfaces.

c. Set the pins of bearing and labyrinth . seal in pin holes of crankcase upper by moving the bearings and labyrinth seal.

1981 SR540E

FWD

<=

1. Knock pin 3. Upper case

2. Sealing surface 4. Aligning mark

CAUTION:------------------~

The oil seal lip must fit into the crankcase groove.

6. Crankcase installation a. Apply YAMAHA BON D #4 to the mat

ing surfaces of both case halves. Apply thoroughly over all matching surfaces.

b. Set the crankcase half onto lower case half. Install the crankcase holding bolts. Each bolt position is numbered. Tighten all crankcase holding bolts gradually in the order of the numbers marked on crankcase.

Tightening torque

First 1.0 m-kg (7 ft-Ib) 8 mm Bolt

Final 2.0 m-kg (15 ft-Ib)

6 mm Bolt First 0.5 m-kg (3.5 ft-Ib) (No.ll ) Final 1.0 m-kg (7 ft-Ib)

2-8

c. After reassembly. apply a liberal coating of two-stroke oil to the crank pin. bearing and into each crankshaft bearing oil delivery hole.

d. Check crankshaft for freedom of movement.

7. Engine bracket installation Install the engine brackets in the correct position.

Tightening torque: 2.0 m-kg (14.5 ft-Ib)

8. Piston pin and bearing inspection a. Check the pin for signs of wear. If any

wear is evident. replace pin and bearing.

b. Check the pin and bearing for signs of heat discoloration. If excessive (indentation on pin. etc.). replace pin and bearing.

c. Check the bearing cage for excessive wear or damage. Check the rollers for signs of flat spots. If such wea~ is found. replace pin and bearing. '

~ ,,~, ,

d. Apply a light film of oil to pin and bearing surfaces. Install them in connecting rod small end to inspect for wear. Check for play. There should be no noticeable vertical play. If play exists. check connecting rod small end for wear. Replace pin. connecting rod and/or bearing. as required.

e. The piston pin should have no noticeable free play in the piston. If the piston pin is loose. replace the pin and/or piston.

2-9

1981 SR540E

9. Piston inspection a. Remove piston rings. b. Remove carbon deposits from piston

crown.

c. Carefully remove carbon deposits from ring grooves with filed end of ring.

d. Remove score marks and lacquer deposits from sides of piston using 600 !"'oJ

800 grit wet sandpaper. Sand in a crisscross pattern. Do not sand excessively.

1981 SR540E

e. Wash piston in solvent and wipe dry. f. Measure the outside diameter of the

piston at the piston skirt. Measurement should be made at a point 17 mm (0.67 in) above the bottom edge of the piston. Place the micrometer at right angles to the piston pin. Piston maximum diameter subtracted from minimum cylinder diameter gives piston clearance. If beyond tolerance. hone cylinder to tolerance or bore to next oversize and fit oversize piston.

1. 17 mm (0.67 in)

Piston clearance: Minimum ........ 0.055 mm (0.0022 in) Maximum ....... 0.060 mm (0.0024 in)

Piston oversize: 73.25 mm (2.884 in) 73.50 mm (2.894 in) 73.75 mm (2.904 in) 74.00 mm (2.913 in)

10. Piston ring inspection

b. Measure ring end gap in free position. If beyond tolerance. replace ring set.

Ring end cap. free Approx. 8 mm (0.31 in)

c. Push the ring into the bore and check end gap clearance with a feeler gauge. If beyond tolerance. replace ring set.

Ring end gap. installed Minimum ............. 0.30 mm (0.012 in) Maximum ............ 0.50 mm (0.020 in)

a. Check rings for scoring any severe scratches and noticed. replace ring set.

11. Piston installation

1. Piston head

<D /11111/11111(5111111111111

________ 'l~ ~ ______ ~ '11111111111JJ1177777171JI

@

2. Piston bottom 3. Piston ring

2·10

a. Install the piston rings as illustrated.

b. During reassembly. coat the piston ring grooves. piston skirt areas. piston pin. and bearing with two-stroke engine oil.

c. Install new piston pin clips and make sure they are full-seated in their grooves.

NOTE:------------------------Take care during installation to avoid damaging the piston skirts against the crankcase as the cylinder is installed. Be sure the arrow stamped on the piston crown points forward.

12. Cylinder inspection a. Inspect the cylinder walls for scratches.

If vertical scratches are evident. the cylinder wall should be rebored or the cylinder should be replaced.

NOTE:-------------------------Cylinder size mark is stamped upper part of the intake port.

b. Measure cylinder wall wear as shown. If wear is excessive. compression pressure will decrease. Rebore the cylinder wall and replace the piston and piston rings. Cylinder wear should be measured at three depths with a cylinder bore gauge. (See illustration)

2-11

1981 SR540E

2 ......... ~ ...... --------~ ..... ----------

3

------ Standard Wear limit

Cylinder bore 73.00~ 73.02 mm 73.05 mm (2.874~2.875 in) (2.876 in)

Cylinder taper 0.05 mm - (0.002 in)

Cylinder 0.01 mm -

out-of-round (0.004 in)

If the cylinder wall is worn more than wear limit. it should be rebored.

13. Cylinder installatior a. Install a new cylinder base gasket. b. Install cylinder with one hand while

compressing piston rings with other hand.

NOTE:-----------------------Make sure the rings are properly positioned.

1981 SR540E

c. Working in a crisscross pattern, tighten the cylinder nuts in two steps.

Cylinder holding nut torque: 2.5 m-kg (18 ft-Ib)

14. Cylinder head inspection a. Remove spark plug. b. Using a rounded scraper, remove

carbon deposits from combustion chamber. Take care to avoid damaging spark plug threads. Do not use a sharp instrument. Avoid scratching the aluminum.

15. Cylinder head installation Install cylinder head gasket and cylinder head. Working in a crisscross pattern, tighten head nuts in two steps.

Head nut torque: 2.5 m-kg (18 ft-Ib)

16. Intake manifold installation a. Clean the mating surfaces of cylinder,

reed valve and intake manifold. b. Coat the mating surfaces of cylinder,

reed valve and intake manifold with Three Bond #50 and install new intake manifold gaskets.

2·12

c. Install the reed valve and intake manifold.

Tightening torque: 1 .0 m-kg (7 ft-Ib)

NOTE:-----------------------For reed valve inspection, see "3-2. REED VALVE"

17. Exhaust pipe installation Remove the carbon deposits from exhaust pipe. Inspect the exhaust gasket for damage and replace it as required. Install the exhaust pipe with gasket.


18. Install air shroud.

Tightening torque: 0.6 m-kg (4 ft-Ib)

B. Oil pump 1. Minimum pump stroke checking and ad

justment. Normally the checking the adjustment of the pump stroke are not required, but if any sign of trouble resulting from an incorrect minimum pump stroke is noticed (e.g., excessive engine oil consumption or engine s~izure). proceed as follows:

a. Remove the oil pump assembly from the engine.

b. Turn the oil pump worm wheel until the pump plunger moves fully out and away from the pump body to its outermost limit.

c. Measure the gap with the thickness gauge between the raised boss on the pump adjust pulley and the adjust plate.

1. Adjust plate 2. Adjust pulley

3. ~inimum pump stroke

Minimum pump stroke: 0.20,...... 0.25 mm

. (0.0079,...... 0.0098 in)

d. If clearance is not correct, remove the adjust plate lock nut and the adjust plate.

e. Remove or add an adjust shim as required.

2-13

1981 SR540E

1. Adjust shim

f. Reinstall adjust plate and lock nut. Tighten the lock nut. Re-measure gap. Repeat procedure as required.

2. Oil pump drive case installation Coat the pump drive gear with grease. And install the pump drive case.

Recommended grease: Low temperature grease (Esso Beacon 325 or Aeroshell grease #7A)

Pump case tightening torque: 1 .0 m-kg (7 ft-Ib)

3. Install pump wire, pump case and oil delivery pipe.

CAUTION: ---------..., Before installing pump wire and pump case, apply grease to the pump pulley thoroughly.

Recommended grease: Low temperature grease (Esso Beacon 325 or Aeroshell grease #7A)

4. Air bleeding (After remounting engine) The oil pump and delivery lines must be bled on the following occasions:

• Setting up a new machine out of the crate.

• Whenever the oil tank has run dry. • Whenever any portion of the oil pump

system is disconnected.

1981 SR540E

a. Bleeding the pump case and/or oil pipe. 1) Remove the oil pump bleed screw.

1. Bleed screw

2) Keep the oil runnin,g out until air bubbles disappear.

3) When air bubbles are expelled completely, tighten the bleed screw.

NOTE:----------------------Check the bleed screw gasket, and if damaged, replace with a new one.

b. Bleeding the pump distributor and/or delivery pipe.

1) Start the engine. 2) Pull the pump wire all the way out to

set the pump stroke to a maximum.

1. Pull

2. Pump wire

NOTE:-----------------------It is difficult to bleed the distributor completely with the pump stroke at a minimum, and therefore the pump stroke should be set to a maximum.

2·14

3) Keep the engine running at about 2,000 r/min for two minutes or so, and both distributor and delivery pipe can be completely bled.

5. Cable adjustment (After remounting engine)

a. Adjust throttle cable free play. (See 3-1-A. Carburetor tuning)

b. Pull the oil pump cable outer tube toward the oil pump and adjust the gap between the adjuster and the outer tube to specification,

Play: 25 ± 1 mm (0.98 ± 0.04 in)

c. After adjusting, don't forget to tighten the lock nut.

1. Play 2. Adjuster

3. Lock nut

C. Flywheel magneto (For inspection, refer to "6-1-G. Pulser and charge coil test" and "6-2-C. Lighting circuit test",)

Inspection Check the flywheel magneto for any looseness, If it is loose, retighten to the following torque and apply an adhesive,

Tightening torque: Weight ring and ring gear stay:

1 ,0 m-kg (7,2 ft-Ib) Flywheel magneto and ring gear stay:

1.5 m-kg (10.8 ft-Ib)


Tightening torque:

1.5 m-kg (1 O.S ft-Ib)

@ : LOCKTITE® LOCK "n" SEAL (adhesive)

1. Weighr ring 4. Hexagon socket head bolt

2. Ring gear stay 5. Solt

3. Spring washer 6. Spring washer

1. Install woodruff key. 2. Install flywheel base.

Flywheel base tightening torque: 0.65 m-kg (5 ft-Ib)

3. Install flywheel using sheave holder.

Too name Tool No:

Sheave holder 90890-01701

NOTE:-------------------------Make sure woodruff key is properly seated in keyway of crankshaft. Carefully install flywheel while taking care so it aligns with woodruff key.

Flywheel nut torque: 7.3 m-kg (53 ft-Ib)

4. Adjust ignition timing.

CAUTION:------------------~ Whenever the flywheel magneto is removed, ignition timing must be reset. (Refer to 6-1-C. Ignition timing)

2-15

D. Cooling fan 1. Inspection

1981 SR540E

a. Check the fan shaft bearings for damage. If damaged, replace.

b. Check the cooling fan for damage. If damaged. replace.

c. Check the fan belt for damage and wear. If worn excessively. replace.

2. Installation a. Install the cooling fan assembly and fan

driven pulley assembly.

Driven fan pulley securing nut torque: 4.3 m-kg (31.1 ft-Ib)

NOTE:------------------------For shim installation. see fan tension adjustment of next section.

b. Install the fan case assembly.


c. Install the fan drive pulley with fan bent.

1981 SR540E

d. Install the starter pulley.

e. Install the fan case cap.

Fan Case Assembly

14

2

Tightening torque: 2.3 m·kg (16.6 ft-Ib)


11 9

10 7

8

7

5

5

2·16

12


Ref. No. Description a'ty Remarks

Fan case

2 Bearing (B6203) 2

3 Circlip

4 Plate washer

5 Fan

6 Woodruff key

7 Pulley 2 2

8 Claw washer

9 Spring washer

1 UR

1

10

11

12

+ +

Plain washer

Nut

Belt

Pulley 1

Fan case cover

7


11

3. Fan belt tension adjustment The fan belt tension should be checked by pushing the belt 8 mm (0.31 in) at its center. If the tension is less than the specified value. adjust the· fan belt.

Fan belt tension: New belt (preset tension)

6.5 f""'oJ 8.5 kg/8 mm (14.3 f""'oJ 18.7 Ib/0.31 in)

Normal 4f""'oJ 6 kg/8 mm (8.8 f""'oJ 13.2 Ib/0.31 in)

a. Remove the fan drive pulley and the fan belt.

b. Remove the fan driven pulley. c. Remove or add adjusting washers as re

quired.

Washer q'ty Decrease -- Increase

Belt tension Increase -- Decrease

Washer parts No. Thickness

90214-17017 0.5 mm (0.02 in)

90214-17018 1.0 mm (0.04 in)

2-17

1981 SR540E

NOTE:-------------------------Take care so that adjusting washers are not lost.

d. First. install the fan driven pulley. Next. install the fan drive pulley with fan belt.

Tightening torque

Fan driven puiiey 4.3 m-kg (31.1 ft-Ib)

Fan drive pulley 2.3 m-kg (16.5 ft-Ib)

CAUTION: ----------, Before tightening fan driven pulley securing nut, do not install fan belt.

e. Check the fan belt tension If the tension is not correct. readjust the belt tension by repeating the procedures a. from d. above. until tension is correct.

f. After adjusting fan belt tension correctly tighten the fan driven pulley. securing nut. spring washer and plain washer.

1. Fan shaft 3. Spring washer 2. Plain washer 4. Nut

1981 SR540E

E. Starter 1. Install the starter spring in the starter

case.

NOTE:------------------------1. It is necessary to wind the spring to a

small size before installing it in the starter case.

2. Be careful' not to install the spring in a wrong way.

3. Hook the loop on the outer end of the spring onto the spring hook in the star

. ter case. Then thoroughly grease the spring.

2. Wind the starter rope around the sheave drum. and put it into the starter case. Hook the knot on the rope end onto the cut in the sheave drum (as illustrated). and wind the rope around the sheave drum in the direction of the arrow. leaving about 370 mm (14.6 in). The other end of the rope is connected to the starter handle.

370mm

3. Bring the rope end out of the cut in the sheave drum. and turn the sheave drum 4 turns counterclockwise to give the starter spring preload. Pull the starter

2-18

handle and release it. making sure that the starter handle returns to the housing rope eye.

4. Place the drive pawl. return spring. drive plate spring. drive plate and tighten the thrust washer and nut.

NOTE:------------------------Grease the pivot of the drive pawl.


5. After the completion of assembly. check the starter for smooth operation. Pull out the starter rope about 80 roo.J

130 mm (3 roo.J 5 in). and make sure that the starter pawl moves out of the drive plate.

1. Drove plate spring

2. Drive pawl

3. Return spring

F. Engine remounting Install the engine as follows:

Engine

Engine mounting nuts

Manual starter handle

Magneto lead wire

Tachometer cable

Carburetor

2-19

1981 SR540~

6. Install the starter assembly on the fan case.

Tightening torque 0.7 m-kg (5.0 ft-Ib)

NOTE:------------------------Refer to .. 4-1-A. Sheave adjustment".

CAUTION: ----------... Take care not to pinch the wire and pipes between the engine and frame.

NOTE:-------------------------For adjusting. see "3-1, Carburetor", For routing. see CABLE ROUTING DIAGRAM.

WARNING:------------~

By turning out the throttle lever 2 or 3 turns, make sure it operates correctly.

1981 SR540E

Pulse pipe

Fuel pipe

Oil pipe

Muffler

Primary sheave

V-belt

Snowmobile

~

2-20

CAUTION: ----------, The oil pipe, in which the oil filter is installed, must be correctly connected to the oil pump.

NOTE:-----------------------After installing oil pipe, the autolube system must be bled. (Refer to 2-2-8-4. Air bleeding)

NOTE:-----------------------Refer to "4-1-8. Primary sheave".

NOTE:~---------------------

For inspection, see "4-1-C. V-belt".

1981 SR540E

CHAPTER 3. CARBURETION

3-1. CARBURETOR .............................................................................................................. 3-2

A. Carburetor tuning ................................................................................................. 3-2

B. Overhauling ........................................................................................................... 3-5

C. Troubleshooting ................................................................................................. 3-10

3-2. REED VALVE ............................................................................................................... 3-12

3-3. FUEL PUMP ................................................................................................................ 3-12

3-4. SILENCER JOINT ....................................................................................................... 3-13

CHAPTER 3. CARBURETION

3-1. CARBURETOR

A. Carburetor tuning 1. Standard specification

The carburetor is set at the factory to run at temperatures of O°C to -20°C (32 ° F to - 4 ° F) at sea level. If the machine has to be operated under conditions other than specified above. the carburetor must be reset as required. Special care should be taken in carburetor setting so that pistons will not be holder or seized.

Main jet #150

Power jet #150

Slow jet #92

Pilot screw 2-1/4 turns out

Starter jet #160

15 +2 mm Float height -3+ 0 .079

in) (0.59 -0.118

Idling engine speed 1.500 r/min

CAUTION: -----------. If the air silencer box is removed from the carburetors, the change in intake pressure will create a LEAN MIXTURE that may result in severe engine damage. The air silence box has no effect on performance characteristics and it must be secured to the carburetor during carb tuning and adjustment. It must always be in place when the engine is operated. Examine the silencer regularly for cleanliness and freedom from obstruction.

2. Carburetor cable adjustment a. Throttle cable adjustment

Check throttle cable free playas specified when throttle closed (idling throttle).

Free play: 1.0'" 2.0 mm (0.04", 0.08 in)

3-2

If free play is not correct. loosen the throttle cable securing screw and adjust throttle cable. After adjusting. be sure to tighten the screw prO.l?erly.

Throttle cable securing screw tightening torque:

0.4 m-kg (3.0 ft-Ib)

1. Screw

WARNING: -----------, Throttle cable must not be lubricated in any way. It must be routed correctly to avoid throttle problems that may lead to an unsafe condition during operation.

b. Starter cable adjustment Pull the starter cable outer tube upward. and adjust the free play between the outer tube end and adjuster to specification by turning the adjuster. After the adjustment. tighten the lock nut and replace the rubber cap to keep the lock nut free from dust and water.

NOTE:-----------------------Starter cable free play must be adjusted after the cable is correctly rounted. (Refer to wire routing diagram.)

Lock nut tightening torque: 0.08 m-kg (0.6 ft-Ib)

0.5 - 1.5 mm (0.02 - 0.06 in)

1. Adjuster

2. Lock nut

Free play between outer tube end and adjuster:

0.5,...., 1.5 mm (0.02,...., 0.06 in)

c. Oil pump cable adjustment Refer to "2-2-8-5. Pump cable adjustment".

3. Low speed tuning The carburetor is built so that low speed tuning can be done by adjusting the throttle stop screw and pilot screw.

CAUTION:------------------~

Always install air silencer before making tuning adjustment. High performance tuning cannot be done without the silencer. Engine damage may result from attempting to tune without the silencer installed.

a. Tighten the pilot screw lightly. and back it out from its lightly seated position.

Standard pilot screw (turns out): 2-1/4 turns out

3-3

1981 SR540E

1. Pilot screw

b. Start the engine by pulling the starter lever. and fully warm up the engine.

c. Set the throttle stop screw so that the engine idles at the specified speed.

Idling engine speed: 1.500 r/min

1. Throttle stop screw

NOTE:-----------------------If the engine shows poor performance in elevation or in an extremely cold area or when it is suddenly accelerated or run at low speeds. proceed as follows:

1. Turn the pilot screw in and out 1/4 turn or less each time. and set it in a position where the engine idles faster.

2. Follow step C" in the preceding paragraph.

4. Main circuit tuning No adjustment is normally required. but adjustment is sometimes necessary depending on tempeatures and/or altitude. (Refer to Main jet setting chart.)

1981 SR540E

[Main jet setting chart]

~ -30°C -20°C

Altitude (-22°F) (-4°F)

~

Seal level 1--(#155) -

~ 600 m (2000 ft) I-- #155 - --~ 1200 m (4000 ft) t---#150 ..

-~ 1800 m (6000 ft) r--- #145 --~ 2400 m (8000 ft) r---#140 .. -~ 3000 m (10000 ft) -#135 -

a. Run the engine at high speeds, and make sure the engine operates smoothly.

c. Check both spark plugs and, depending on the discoloration of each spark plug, the main jet should be adjusted on the basis of the following table. (Refer to spark plug color samples.)

Standard main jet: #150

Spark plug color

No.1 Good (Carburetor is tuned properly.)

Bad (Mixture is too rich.) No.2 Replace main jet with one-step

smaller one.

Bad (Mixture is too lean.) No.3 Replace main jet with one-step

larger one.

Bad (Due to too lean a mixture, piston is holder or seized.)

No.4 Replace the piston and spark plug. Tune the carburetor again, starting with low-speed tuning.

Bad (Due to too lean a mixture, the engine knocks.) Check the piston for holes or seizure.

No. 5 Check the cooling system, gasoline octane rating and ignition timing. After replacing the spark plug, tune the carburetor again, starting with low-speed tuning.

-10°C O°C 10°C 20°C (14°F) (32°F) (50°F) (68°F)

#150

#150

#145

#140

#135

#130

No. 6

----#145-

-- #145 --- #140 -.. - #135 -

-- #130 -• - #125 ..

Bad (Due to lean a mixture, the spark plug melts.)

Check the piston for holes or seizure. Check the cooling system, gasoline octane rating and ignition timing. After replacing the spark plug with colder type, tune the carburetor again, starting with low-speed tuning.

1. Main jet

3-4

WARNING: ------------, Never remove the main jet cover bolt while the engine is hot. Fuel with flow out of the float chamber which could ignite and cause damage to the snowmobile and possible injury to the mechanic. Place a rag under the carburetor so fuel does not speed, Place the main jet cover bolt in a clean place. Keep away from fire. After assembling the carburetor, firmly tighten the rubber joint screw. Make sure the throttle outer tube is in place and the throttle cable moves

smoothly. Clean the carburetor and allow it to dry.

B. Overhauling

6

1. Disassembly

1._14

I=--15

~'6 ~-21

18----9 19~

4-20

a. Remove the carburetor from the engine. and discor;mect the control cables as follows:

1) Loosen the throttle cable holder screw. 2) Remove the pump cable adjuster from

the stay plate. and remove the pump cable from the lever.

3) Remove the cap from the carburetor. together with the starter valve. and disconnect the starter cable.

1. Throttle cable

2. Pump cable

3. Starter cable

3-5

1. Carburetor ass'y

2. Spring

3. Hose

4. Slow jet

5. Float 6. O-ring

7. Float cha mber body

B. Starter plunger cap cover

9. Cable adjuster

10. Starter plunger .cap

11. Nut

12. Starter plunger spring

13. Starter plunger

14. Valve seat ass'y

15. Clip

16. Float pin

17. Main jet

lB. O-ring

19. Drain bolt

20. Pan head screw with Vl(asher

21. Flathead screw

22. Spring

23. Adjust screw

24. Bolt with washer

25. Stay

26. Bolt

27. Pan head screw

2B. Spring

1981 SR540E

1981 SR540E

CAUTION: ---------.., When removing the starter cable, take care so that the rubber cap, coil spring and starter cable do not fall off or are not lost. Also use special care not to scratch the rubber seat surface.

b. Float chamber 1) Remove the four screws. together with

the float cha mber. 2) Remove the main jet cover bolt.

together with the O-ring.

c. Carburetor body 1) Remove the screw. together with the

float. float arm. and fuel valve assembly. 2) Remove the slow jet and main jet. 3) Remove the pilot screw. together with

the coil spring. 4) Remove the throttle stop screw,

together with the coil spring. 5) Remove the stay plate. together with

the bolt.

3-6

NOTE:-----------------------1. Hook the clip orito the float arm. and

remove the fuel valve while taking care not to drop it.

2. The fuel valve plays a very important role. so special care should be taken so that the rubber part of the needle is not scratched.

3. Use care to keep the plastic parts free from shocks. because they could be damaged easily.

4. Never wash the rubber parts with alcohol or lacquer thinner. Use gasoline.

CAUTION:-------------------, Never attempt to disassemble the following parts. 1) Throttle valve 2) Throttle shaft Reason: 1) The threaded portion of the screw is

clinched after the throttle valve is installed to the throttle shaft so that the screw will not come loose.

2) The bypass hole is precisionmachined so that the correct distance can be maintained from the end of the throttle valve. Therefore, if the throttle valve is once disassembled, it is difficult to reproduce the original dimensions, and thus engine performance will be adverselyaffected.

=~::: ':::.1

" II II II II II II II II II

____ ,...L... ___ _

2. Inspection

CAUTION:------------------~

1) Before checking, thoroughly clean all parts in gasoline, and blow the jets, float chamber and fuel passages in the carburetor body with compressed air so the dust and dirt can be removed.

2) When washing the carburetor body and float chamber, be sure to use a soft brush.

3) When decarbonizing the throttle valve and its adjacent area, take special care not to scratch the throttle valve and throttle bore.

4) Never use a hard wire or the like when cleaning jets. It could scratch or deformed jet holes, thus adversely affecting fuel consumption.

5) Use care so that all parts are not deformed.

II II

1 Power air jet (Body jet)

2. Power nozzle

3. Pilot screw

4. Main air jet (Body jet)

5. Power jet (Body jet)

6. Main jet

7. Slow jet

8. Starter jet

9. Slow air jet

=================~ ®

@ I ·11 I II :: @ CV II

~===================~

3-7

1981 SR540E

a. Float chamber 1) Check the starter jet and power jet

circuit for clogging with dust. If clogged, blow them off with compressed air.

NOTE:-------------------------If the starter jet is clogged, fuel flow will be hindered and hard starting will result.

1. Starter jet

2. Power jet circuit

2) Blow the float chamber clean of dust and dirt with compressed air.

b. Carburetor body 1) Clean the fuel valve seat while taking

care not to scratch the seat. and blow it with compressed air. Check the end of the valve needle for damage. If damaged, replace the valve needle. If the valve seat is damaged, the body should be replaced.

CAUTION:------------------~

A scratched seat could result in the overflow of fuel.

2) Check the power jet for clogging. If clogged, blow it with compressed air.

3-8

1. Power jet 3. Slow circuit

2. Main circuit 4. Starter emulsion tube

NOTE:------------------------If this jet is clogged, engine power loss will result at high speed operation.

3) Clean the main circuit. slow circuit and starter emulsion tube, and blow them off with compressed air.

4) Clean the main air jet. slow air jet. starter circuit.' and air vent. and blow them off with compressed air.

1. Main air jet 2. Slow air jet 3. Starter circuit

5) Blow the pilot screw clean of dust and dirt with compressed air.

6) Check the end of pilot screw for carbon. Check the tapered portion and threaded portion for damage.

7) Blow the main jet and slow jet clean of dust and dirt with compressed air.

3. Reassembly and adjustment

CAUTION: ------------, 1) Wash all parts in clean gasoline be

fore assembling. 2) Always use new O-rings. 3) Make sure moving parts rotate or

slide smoothly. 4) Apply grease to contact surfaces of

the throttle shaft.

a. Carburetor body 1) Install the throttle stop screw and coil

spring. Adjustment: See "Low speed tuning."

2) Install the main jet and slow jet. 3) Install the pilot screw and coil spring.

Adjustment: See "Low speed tuning."

NOTE:-------------------------The pilot screw must not be tightened excessively.

4) Install the stay plate. 5) Install the clip to the needle valve, and

put it into the valve seat. Insert the arm pin into the float. install the float. and secure the arm pin with screw.

NOTE:--------------------------1. Don't forget toinsert the float arm tang

into the clip attached to the needle valve.

2. After assembling, take care not to allow dust and dirt to enter.

3-9

1981 SR540E

6) Float level. (1) Reinstall components, except for

the float chamber. (2) Incline the carburetor at 20 "" 30°

(so that the end of the float valve does not hang down of float weight). and measure the distance from the mating surface of the float chamber and carburetor to the top of the float using a gauge.

Float level:

1 5 _+ 32 mm (0.59 + 0.079 in) -0.118

NOTE:-------------------------The float should be just resting on, but not depressing the spring loaded inlet needle.

1. Float level

(3) If the float level is not within the specified range, check the valve seat and needle valve. And replace any damaged part.

(4) If any part is in good condition but float level is not within the specified range, correct float level by bending the float arm tang slightly.

1981 SR540E

~CAUTION:--------------------_

After installing the carburetor body, be sure to apply grease to the following parts as an anti-freeze measure:

Recommended low temperature grease:

ESSO Beacon 325 or Aero Shell #7

1) Throttle return spring, throttle shaft collar.

2) Space between carburetor body and throttle shaft (at 2 places).

3) Throttle lock washer, E-clip. 4) Wire holder attached to the throttle

valve.

b. Float chamber 1) Screw the main jet cover bolt (with 0-

ring) into the float chamber. 2) Install the O-ring to the float chamber,

and install it to the carburetor body.

CAUTION:------------------~

Always use a new O-ring for reassembly.

c. Install the air bent pipe in place. d. Push the carburetor into the rubber

joint. and secure it with the band. 1) Before installing the carburetor on the

engine, connect the control cables in the reverse order of disconnection. Keep the starter valve free from dust and dirt during this operation.

2) Insert the end of throttle wire into the hole in the throttle lever, adjust the play of cable, and secure it with screw. (See "Throttle cable adjustment.")

3-10

NOTE:-----------------------By turning the throttle lever to the full-open position two or three times, make sure it operates correctly.

3) Make sure the starter lever is fully pushed in, and install the starter cable and spring to the starter valve, and install the valve in the carburetor. Adjust the starter cable. (See "Starter cable adjustment.")

NOTE:-----------------------By pulling the starter lever two or three times after installation of the starter cable, check the operation of the starter valve.

4) Install the fuel pipe to the carburetor. Next, install the clip firmly.

C. Troubleshooting This troubleshooting guide relates only to the carburetor. Making an adjustment of the carburetor, check the engine and electrical system. If no defect is found, consult this troubleshooting guide.

CAUTION:------------------~

1) When disassembling the carburetor, use care so that parts don't fall off or are not lost. Also don't strike the carburetor with a hard tool. Dust should be blown off with compressed air.

2) When installing the throttle cable, make sure the throttle valve can be fully opened and closed, and make an adjustment.

1981 SR540E

Trouble Checkpoint Remedy Adjustment

Hard starting Insufficient fuel Add gasoline

Excessive use of starter Clean spark plug Return starter lever to its home (Excessively opened choke) position.

Fuel passage is clogged or Clean Parts other than carburetor

frozen • Clogged fuel tank air vent. clogged

fuel filter. or clogged fuel passage

Carburetor Clogged or frozen air vent clogged

valve . If water collects in float chamber •

clean (Also check for ice.)

Overflow Correct See "Overflow"

Poor idling Improper idling speed Tighten pilot screw lightly. and check adjustment throttle opening. If incorrect. back it

(Relative troubles) Pilot screw adjustment Adjust idling speed out specification. Start the engine

· Poor performance at low and turn pilot screw in and out speeds 1/4 turn each time. When the engine

· Poor acceleration runs faster. back out throttle stop

· Slow response to throttle screw so the engine idles at

· Engine tends to stall specified speed. • Throttle stop screw Adjust Tightened to much-Engine speed

is higher.

Backed out too much-Engine does

no idle.

Damaged pilot screw Replace pilot screw

Clogged bypass hole Clean

Clogged or loose slow jet Clean and retighten Remove slow jet. and blow it out

with compressed air.

Air leaking into carburetor joint Retighten band screw Defective starter valve seat Clean or replace

Overflow Correct See "Overflow."

Poor performance at Clogged or loose slow jet Clean and retighten Remove slow jet. and blow it out mid-range speeds with compressed air. (Relative troubles)

· Momentary slow response

to throttle

· Poor acceleration Lean mixtures Overhaul carburetor See "Overflow."

Poor performance at normal Clogged air vent Clean Remove the air vent pipe. speeds and clean. (Relative troubles) Clogged or loose main jet Clean and retighten Remove main jet. and blow it out · Excess fuel consumption

with compressed air. · Poor acceleration Overflow Check float and float valve See "Overflow"

and clean

Poor performance at high Starter valve is left open Fully close valve Return starter lever to its home speeds position (Relative trouble)

Clogged air vent Remove and clean · Power loss

· Poor acceler'ltion Clogged or loose main jet Clean and retighten Remove main jet. and clean with compressed air. then install.

Clogged power jet Clean

Clogged fuel pipe Clean or replace

Dirty fuel tank Clean fuel tank

Air leaking into fuel line Check jOint and retighten

Low fuel pump performance Repair pump or replace

Clogged fuel filter Replace

Clogged silencer outlet Check for ice. and remove

3-11

1981 SR540E

Trouble Check point

Abnormal combustion Lean mixtures

(Mainly backfire) Dirty carburetor

Dirty or clogged fuel pipe

Overflow Clogged air vent (Relative troubles)

Clogged float valve Power idleing

Poor performance at low.

mid-range. and high Scratched or unevenly worn

speeds float valve or valve seat

Excessive fuel consumption

Hard starting Broken float Power loss

Poor acceleration I ncorrect float level

• Worn float tang

• Worn arm pin

· Deformed float arm

3-2. REED VALVE

1. Remove the reed valve assembly. (Refer to 2-1-F. Engine disassembly)

2. Inspect rubber carburetor joint for signs of weathering. cracking or other deterioration.

3. Inspect reed petals for signs of fatigue and cracks. Reed petals should fit flush or nearly flush against neoprene seats. If in doubt as to sealing ability. apply suction to carburetor side of assembly. Leakage should be slight.

4. Check valve stopper clearance. If beyond tolerance. replace valve stopper.

Valve stopper clearance: 9.7 ± 0.3 mm (0.38 ± 0.012 in)

Remedy Adjustment

Clean carburetor and adjust

Clean carburetor

Clean or replace fuel pipe

Clean

Disassemble and clean Clean while taking care not to

scratch valve seat.

Clean or replace float valve Valve seat is press-fitted to body.

and valve seat So body must be replaced if seat is

damaged.

Replace float

If not within the specified

range. check the following parts

and replace any defective part

Replace float Replace float assembly.

Replace arm pin

Replace float

3-12

5. Check reed valve for beinding. If beyond tolerance. replace reed valve.

Reed valve beinding limit: 0.6 mm (0.024 in)

6. If disassembly of the reed valve assembly is required. proceed as follows:

a. Remove Phillips screws securing stopper plate and reed to reed block. Handle reed carefully. Avoid scratches and do not bend. Note from which side of the reed block the reed and stopper plate were removed. Re-install on same side.

NOTE:-------------------------During reassembly. note the cut in the lower corner of the reed and stopper plate. Use as aid to direction of reed installation.

b. During reassembly, clean block, reed and stopper plate throughly. Apply a holding agent. such as "Lock-Tite" to threads of Phillips screws. Tighten each screw gradually to avoid warping.

Torque: 0.08 m-kg (0.6 ft-Ib)

7. During reassembly of the reed valve assembly and manifold, install new gaskets and torque the securing bolts gradually and in a crisscross pattern to the proper torque.

Reed valve securing bolt torque: 1.0 m-kg (7 ft-Ib)

3-3. FUEL PUMP

Check to see if fuel moves from tank to carburetor, and if any fuel leaks from pipe joints or fuel pump body. Replace fuel pump assembly as required.

1. Fuel pump·

3-13

1981 SR540E

3-4. SILENCER JOINT

1. To protect the silencer joint against deformation, a steel band is used.

-CAUTION: ----------A deformed silencer joint will result in an imbalance of temperatures of the right and left spark plugs. Don't forget installing the band.

1. Silencer joint

2. Band

2. Assembly procedure a. The band has six holes. Install the band

so that its largest hole fits over the largest projection on the silencer joint and other small five holes over the protuberances one by one.

NOTE: Pull the projection using pliers so that the

band tightly fits the silencer joint.

b. Cut off the tip of the projection.

1981 SR540E

CHAPTER 4. POWER TRAIN

4-1. DRiVE ............................................................................................................................. 4-2

A. Sheave adjustment .............................................................................................. 4-2

B. Primary sheave ..................................................................................................... 4-3

C. V-belt. ..................................................................................................................... 4-8

D. Secondary sheve .................................................................................................. 4-8

E. Chain housing ................... , .................................. .............................................. 4-12

F. Front axle ............................................................................................................ 4-16

4-2. BRAKE ......................................................................................................................... 4-19

A. Disassembly ....................................................................................................... 4-19

B. Inspection ........................................................................................................... 4-19

C. Reassembly ................................................................................................ ····· ... 4-19

D. Adjustment ........................................................................................................ ,4-19

4-3. SUSPENSiON ............................................................................................................. 4-20

A. Removal ............. : ................................................................................................. 4-20

B. Inspection ................................................................................................. ·········,4-21

C. Slide rail suspension adjustment ................................................................... 4-22

D. Installation ......................................................................................................... 4-24

4-4. DRIVE TRACK ............................................................................................................ 4-24

A. Removal ............................................................................................................. 4-24

B. Inspection .......................................................................................................... 4-24

C. Installation ........................................................................ , ................................. 4-24

D. Adjustment ........................................................................................................ 4-25

1981 SR540E

CHAPTER 4. POWER TRAIN 4-1. DRIVE

A. Sheave adjustment Use the sheave gauge to check the following:

• Center to center distance between the primary and secondary sheaves.

• Off-set between the inside edge of the sheaves.

• Alignment of sheaves.

r----- 1CD----1

1. Sheave distance 2. Sheave off-set

270~~ mm(10.63~gll in) 11 ± 0.5 mm (0.433 ± 0.020 in)

Sheave distance check

1. Sheave gauge

Sheave offset/alignment check Place the sheave gauge against inner surfaces of the primary fixed sheave and the secondary sliding sheave. If t,/le sheave gauge contacts the sheaves at four points as illustrated, the offset is correct.

NOTE:------------Be sure to remove the V-belt before adjusting the sheave offset.

4-2

1. Sheave gauge

If any of these is incorrect. proceed as follows:

1. Loosen the engine mounting nuts. 2. Adjust sheave distance, off-set and

alignment by moving the engine back, forth or sideways.

Tool name Tool No.

Sheave gauge 90890-01702

Sheave distance: o +0

270 ~3 mm (10.63 -0.11 in)

Sheave off-set: 11 ± 0.5 mm (0.433 ± 0.020 in)

NOTE:-------------If sheave off-set is not adjusted at above procedure, remove the secondary sheave assembly, and adjust the sheave off-set by installing or removing the plate washers from the secondary shaft.

Parts name Thickness

Plate washer (90201-25526) 2 mm (0.08 in)

Plate washer (90201-25527) 1 mm (0.04 in)

CAUTION: ----------, Must be installed the washers at least 2 pieces (3 mm or more thickness).

3. Tighten the engine mounting nuts.

Tightening torque: 5.2 m-kg (37.6 ft-Ibl

B. Primary sheave 1. Removal a. Remove the V-belt. b. Straighten the lock washer tab. and re

move the primary sheave mounting bolt. using the sheave holder.

Tool name Tool No.

Sheave holder 90890-01701

1. Sheave holder

c. Remove the primary sheave assembly. using the primary fixed sheave puller and sheave holder.

Tool name Tool No.

Primary fixed sheave puller 90890-01897

Primary fixed sheave attachment 90890-01899

4-3

1981 SR540E

1. Primary fixed sheave puller

2. Disassembly a. Install the sheave sub-assembly tool to

the primary sheave.

Tool name Tool No.

Sheave sub-assembly tool 90890-01858

1. Sheave sub-assembly tool

b. Loosen the six bolts securing the primary sheave cap and sliding sheave.

c. Remove the sheave subassembly tool. The primary sheave cap and sliding sheave can now be disassembled.

3. Inspection a. Check the tapered ends of the crank

shaft and primary fixed sheave for scratches. If scratched unduly. replace. If scratches are minor. burnish with emery cloth.

b. Check the primary sheave cap bushing and sliding sheave bushing for wear. If beyond tolerance. replace the bushing.

Bushing clearance, limit

Small bushing Large bushing

Inside 0.25 mm (0.01 in) 0.25 mm (0.01 in)

Outside 0.25 mm (0.01 in) 0.25 mm (0.01 in)

1981 SR540E

~ Setting parts

Parts No.

Color code Spring

Set load

Spring constant

Parts No.

Counter sunk rivet Set holes

Weight Parts No.

NOTE:----------------------~ If bushing is installed tightly, remove the bushing using the bushing tool.

Tool name Tool No.

Bushing tool 90890-01883

1. Bushing tool

c. Check the compression spring for fatigue. If excessively fatigued, replace.

d. Check the spider and roller for smooth movement and wear.

e. Check both sheaves for warping. If warped, replace.

4. Adjustment The primary sheave tuning should be set according to the altitude.

Sea level (Std.) High altitude

(Up to 1 500m (5000 ftl) (About 1500m (5000 ft)

or more)

90501-50500 90501-55487

Red Silver-Silver

25 kg 50 kg

1.4 kg/mm 2.0 kg/mm

90261-06015 90261-0601 5

r---

r9\ ~ - Rivet

0 '6 No rivet

0 0

8L9-17632-00 8L8-17632-00

44

NOTE:-------------------------On the sea level (Up to 1500 m). if engine power is poor with snow condition. adjust sheave at the high altitude setting.

a. Compression spring Clutch engagement rpm must be adjusted to specification using on optional compression spring.

b. By changing the position and quantity of primary weight rivets. the thrust of weight can be changed, and thus the engine rpm at which the clutch is shifted can also be changed. (As a result. the engine rpm at which the clutch is engaged can be changed.)

CAUTION: ------------. The rivets for three weights must be in the corresponding positions.

Rivet Shifting rpm

No rivet is in use rpm increases. CD

®

CD®

8L9

1 rpm

decreases.

O--CD

O--®

4-5

1981 SR540E

5. Reassembly a. Adjust the slider button-to-guide clear

ance using shims as required under the slider button.

Slider button-to-guide clearance: 0", 0.2 mm (0", 0.008 in)

Thickness

Shim (90201-090A4) 0.3 mm (0.012 in)

Shim (90201-097 A8) 0.2 mm (0.008 in)

1981 SR540E

b. Oil the points shown in the illustration. Do not apply the grease on the portion of X mark. For other parts. greasing is unnecessary.

-x Free from oil - Greasing point

CAUTION:------------------~ When the bushing is replaced with new one, apply molybdenum disulfide grease to bushing lightly. Except for this, don't grease.

pin is removed for the greasing, replace it with new one.

c. Install the component parts to the sliding sheave and the sheave cap.

NOTE:------------------------1. When installing the spider and primary

sheave cap to the primary sliding sheave. be sure to align the X marks on the spider and sheave cap with that on sliding sheave.

4-6

2. When installing the spacer and collar to the spider. the spacer and the spider projections must be fitted to the collar slit.

Lock washer Spacer

~-~, -+--+-+-.

o

c. Install the sheave sub-assembly tool and tighten the cap.

d. Tighten the six primary sheave cap bolts and remove the sub-assembly tool.


CAUTION: ------------------....... Make sure that the primary sheave cap assembly slides in contact with the fixed sheave boss.

e. With the spider projection being in the receiving recess in the collar, (on the sliding sheave side: see photo)

put a mark on the sheave cap in line with either notch in the other end of the same collar. This mark will later serve as an effective guide for confirmation of corrrect fitting.

4-7

1981 SR540E

f. Clean the oil off the tapered portion of crankshaft using a lacquer thinner.

No oil

g. Fit the primary sheave assembly to the tapered portion of crankshaft.

h. Apply engine oil to the threaded portion of primary sheave bolt and its contact surface with spring washer.

i. Tighten the primary sheave mounting bolt, using the sheave holder. Next, lock

the lock washer.

NOTE: Check the lock washer, and if damaged, replace with a new one.

1981 SR540E

Tightening torque: First tighten the bolt to a torque of A, then loosen it. Retighten bolt to a final torque of B.

A: 12 m-kg (87 ft-Ib) B: 6.5 m-kg (47 ft-Ib)

C. V-belt Check the drive V-belt for damage and wear. If the width is less than specified value, replace with a new belt.

[ Wear limit: 26 mm (1.02 in)

1. New: 31.5 mm (1.24 in) 2. Wear limit: 26 mm (1.02 in)

D. Secondary sheave 1. Disassembly a. Apply the brake and remove the secon

dary sheave mounting bolt. b. Remove the secondary sheave as

sembly and plate washers.

c. Remove the circlip and disassemble the secondary sheave component parts.

4-8

2. Inspection a. Check the ramp shoes on secondary

sliding sheave for wear. Replace ramp shoes as required.

b. Check the sheave bushing for wear. Replace the sheaves as required.

c. Check torsion spring for fatigue. If excessively fatigued, replace.

d. Check both sheaves for warpage. If warped replace.

3. Secondary sheave spring adjustment It is advisable to change the secondary sheave setting to correspond to the course and snow conditions. This is done by changing the secondary spring preload. The spring seat (see illustration) has 4 spring holes. The spring tension (preload) can be adjusted by selecting a spring in the seat and twisting the seat to engage the sheave ramps. In this way the preload can be adjusted in 30° steps.

1981 SR540E

[Secondary spring setting]

Course Trail and tour Lake surface

Setting factor Position of spring seat Twist Position of spring seat Twist

Ice snow Std. Std. No.2 180 0

Packed snow Std. Std. Std. or No.2 Std. or 180 0

Wet snow Std. or No.4 Std. or 240 0 Std. Std.

Std. secondary spring: PIN: 90508-45286 Color code: Yellow

Std. secondary spring position: NO.3

Std. secondary spring twist: 210 0

a. Secondary spring position The spring seat is provided with four holes. Nos. 1 to 4, so that the secondary spring position can be changed as required.

A. Spring seat

b. Secondary spring tension The secondary spring tension can be changed by moving the spring position from the free position in order to reset the clutch shifting RPM as required. The four holes are spaced at intervals of 30°.

Secondary spring Spring wind position

No.1 30°,150°.270°

No.2 60°,180°

No.3 90°,210°

No.4 0°,120°,240°

4-9

Winding the spring more (e.g., from 30° to 60°) will increase the clutch shifting rpm and vise versa. Snow conditions will also require a change of the spring tension in orde to attain the standard shifting rpm. The spring tension must be greater on wet snow than on packed snow, and less tension is needed on icy snow.

4. Reassembly a. Grease the secondary shaft. and sliding

sheave boss and mount the sliding sheave on the shaft.

Recommended grease: Molybdenum disulfide snowmobile

grease

Secondary Sheave Assembly

7

/ 11

~ / 12 z? . ~ / 14

~ ~,/13 ~. "" ~/

~'

Molybdenum disulfide snowmobile grease <J1] (Wear-resistant grease)

FWD

I Clearance: 0.1 ~ 1.0 mm


16

10

3

1 . Secondary fixed sheave compo

2. Secondary sliding sheave

3. Lamp shoe

4. Secondary spring seat

5. Plain washer

6. Circlip

7. Secondary shaft

8. Plain washer

9. Washer based bolt

2

5 6

4-11

14

11

10. Plain washer

11. Eccentric bearing

12. Bearing housing

13."Bolt

14. Spring washer

15. Plain washer

16. Collar

17. Torsion spring



1981 SR540E

1981 SR540E

E. Chain housing 1. Disassembly a. Remove the chain housing cap and

drain the chain housing oil.

b. Apply the brake and remove the cotter pin and the drive sprocket nut and driven sprocket bolt.

c. Loosen the chain tensioner and remove the drive. driven sprockets and chain.

d. Remove the bearing inner race securing screw. and loosen the inner race by using eccentric bearing installer.

Tool name Tool No.

Eccentric bearing installer 90890-01851

4-12

1. Eccentric bearing installer

e. Remove 3 bolts.

f. Remove the brake caliper assembly. (Refer to 4-2. Brake section)

g. After removing the suspension assembIy, remove the two bolts mounting the chain housing. (Refer to 4-3. Suspension)

h. Remove the chain housing assembly. i. Remove the brake disc and key.

j. Remove the secondary shaft complete.

Trail riding

Snow condition ICY Packed Wet

Drive chain sprocket Std. Std. 16

Driven chain sprocket Std. Std. Std.

Chain Oinks) Std. Std. Std.

c. Sprocket ratio and chain link chart The following sprockets. drive and driven. and chains are available as options. The figures in upper lines repre-

ICY

Std.

Std.

Std.

4-13

1981 SR540E

2. Inspection a. Drive chain

Except in case of oil starvation. the chain wears very little. If the chain has stretched excessively and it is difficult to keep the proper chain tension. the chain should be replaced.

b. Drive. driven and chain tension sprockets. Check sprocket for obvious wear. Replace sprocket as required.

c. Bearing selection Check the chain case bearings and oil seals for damage. If damaged. replace.

3. Gearing selection The reduction ratio of driven sprocket to drive sprocket must be set according to the snow condition. Many rough surfaces or unfavorable snow conditions; the driven/drive sprocket ratio should be made larger. Few rough surfaces or better snow conditions; the ratio should be made smaller.

a. Std. reduction ratios

Drive chain sprocket 17 (PIN 878-17682-70)

Driven chain sprocket 31 (PIN 878-47587-00)

Chain (Links) 66 (PIN 94850-35066)

b. A guide to reduction ratios

Lake course High altitude

(Up to 1500 m or more)

Packed Wet ICY Packed Wet

Std. 16 or 15 15 15 Std.

Std. Std. 33 33 33

Std. Std. Std. Std. Std.

sent the driven/drive sprocket ratios. while those in lower lines represent the number of chain links.

1981 SR540E

sprocket 15 16 17

~ PIN 878 PIN 878 PIN 878 Teeth of 17682-50 17682-60 17682-70 driven sprocket

29 1.933 1.813 1.706 PIN 878-47548-90 64 66 66

31 2.067 1.938 1.824 PIN 878-47587-00 66 66 66

33 2.200 2.063 1.941 PIN 888-47587-10 66 68 68

35 2.333 2.188 2.059 PIN 878-47587-20 68 68 68 or 70

Chain links Part No.

64 94890-03064

66 94850-35066

68 94850-35068

70 94850-35070

4. Reassembly a. Apply a low temperature grease to the

chain housing oil seal lip. Install the secondary shaft complete with brake disc.

NOTE:-----------------------Make sure woodruff key is properly seated in key way of secondary shaft. Install brake disc so that it aligned with the woodruff key.

b. Use the two bolts to mount the chain housing to frame.


c. Install the brake caliper assembly.

Brake caliper mounting bolt tightening torque:

4.8 m-kg (35 ft-Ib)

18 19 20 21 22 PIN 878 PIN 878 PIN 878 PIN 878 PIN 878

17682-80 17682-90 17693-00 17693-10 17693-20

4-14

1.611 156

1.722 68

1.833 68

1.944 70

1.526 1.450 1.381 1.318 66 68 68 68

1.632 1.550 1.476 1.409 68 68 68 70

1.731 1.650 1.571 1.500 68 or 70 70 70 70

1.842 1.750 1.667 1.591 70 70 70 or 72 72

d. Install the drive and driven sprockets with chain. Place the collar into the drive sprocket. Tighten the drive sprocket nut and fit a new cotter pin. Don't forget to bend the cotter pin's ends. Tighten the driven sprocket bolt.

Tightening torque: Drive sprocket nut:

6.0 m-kg (43.5 ft-Ib) Driven sprocket bolt:

4.8 m-kg (35 ft-Ib)

e. Tighten the bearing inner race by using eccentric bearing installer.

1. Eccentric bearing installer

f. Tighten the bearing inner race securing screw.


g. Install the gasket and chain housing cap.


h. To add gear oil. the filler cap and oil level screw should be removed.

1. Oil level screw

4-15

1981 SR540E

Fill until oil begins to run out the screw hole.

Recommended oil: Gear oil API "GL-3" SAE #75 or #80

Quantity: 250 cc (8.5 OZ)

After adding oil. be sure to install and tighten the level screw and filler cap.

i. Drive chain tension adjustment Remove the lock nut. Turn in the adjust bolt clockwise finger-tight. Then tighten the lock nut with a spanner while keeping the adjust bolt steady with the other spanner.

Chain free play: 8 '""""' 15 mm (0.32 '""""' 0.59 in)

Lock nut tightening torque: 3.5 m-kg (25 ft-Ib)

1. Chain free play 8 ~ 15 mm (0.3 - 0.6 in)

1. Adjusting bolt 2. Lock nut

1981 SR540E

F. Front axle 1. Removal a. Remove the slide rail suspension as

sembly. (See 4-3. Suspension) b. Remove the speedometer gear housing

and the joint.

c. Remove the nut mounting the front axle. collar. and bearing. (Lock the front axle by applying the brake.)

d. Remove the chain housing cap. (Refer to "Chain housing".) Drain oil and remove the chain driven sprocket.

e. Loosen set bolt CD using a 3 mm hex. wrench and slide guide wheel ®. before pulling out the front axle.

4-16

':1 {r-11,.1 "I ~ , r+~ '---'"

1. Set bolt 2. Guide wheel

f. To remove the wheel sprocket from the axle. loosen the collar and push out using a press.

2. Inspection Check wheel sprocket for damage and wear. Replace wheel sprocket as required.

3. Installation a. When installing the wheel sprocket to

the front axle. position the wheel sprockets on the front axle as shown. Use a press.

FWD

l! 104 mm (4.09 in)

b. Be sure the sprocket teeth are aligned as shown. After positioning. tighten the collar and clamp.

Tightening torque: 0.55 m-kg (4 ft-Ibl

c. Apply a low temperature grease to the front axle. and install the collar. bearing. belleville washer and front axle nut.


4-17

104 mm (4.09 in)

59mm : (2.32i~

I Tightening torque: 0.55 m-kg

1981 SR540E

Then. slide guide wheel ® to the left until it comes in full contact with collar <D and secure set bolt @ using a 3 mm hex. wrench.

1. Set bolt

iJ FWD

1. Collar 2. Guide wheel 3. Set bolt

1981 SR540E

d. Install the speedometer gear housing together with bearing cover and joint.


FWD

e. Apply a low temperature grease to the chain case oil seal. and insert the righthand side of front axle into chain case through drive track. Tighten the front axle with chain driven sprocket.

4-18

1. Bearing cover

2. Joint

3. Speedometer gear housing

4. Collar

5. Guide wheel

6. Collar

7. Set bolt

8. Bearing

9. Belleville washer

10. Nut


f. Install the chain housing cap and add oil. (See "4-1-E-4. Chain housing")

g. Install the slide rail suspension assembly. (See "4-3-0. Suspension installation")

4-2. BRAKE

A. Disassembly 1. Remove the brake cable from the brake

caliper. 2. Remove the brake caliper assembly.

3. Remove the brake pads.

NOTE:-----------------------For brake disc removing. refer to "4-1-E-1. Chain housing".

B. Inspection 1. Check the pads for damage and wear. If

the thickness is less than specified below. replace pads as a set.

Wear limit: 9.5 mm (0.37 in)

1. New: 13.5 mm (0.53 in) 2. Wear limit: 9.5 mm (0.37 in)

2. Check the brake disc for warpage. If warped. replace.

3. If the brake lever will not return smoothly to the rest position because of a fatigued return spring. replace the return spring.

4-19

1981 SR540E

C. Reassembly 1. Apply a low temperature grease to the

back up plate shaft and screw cam.

2. Install the brake caliper with brake pads to the chain housing.


3. Install brake cable to the caliper and brake lever.

CAUTION: ----------, Apply a small amount of antifreeze grease to the contact areas of the brake wire with brake lever stopper surface, but do not apply a grease between the outer wire and inner wire.

D. Adjustment 1. Loosen the lock nut (j) and turn the ad

justing bolt ® to set the "L" distance to the specification below.

L = 57 mm (2.24 in)

Next. lock the adjusting bolt with the lock nut.

1981 SR540E

1. Lining pad 4. Back-up plate 7. Lock nut

2. Brake disc 5. Nut B. Adjusting bolt

3. Screw 6. Brake wire

CAUTION:~----------------~ After step 1, be sure to take step 2, and3.

2. Loosen the nut @ and back out the screw @.

Insert a 0.15 mm feeler gauge between

the lining pad CD and brake disc ® , and by turning the screw @ so that the clearance between the pad and disc is 0.15 mm.

1. Adjusting bolt

2. Lock nut

4-20

3. After locking the nut @, insert the feeler gauge again into the clearance and make sure the clearance is 0.15 mm.

Clearance = 0.15 mm

1t FWD O.15mm

4-3. REAR SUSPENSION

A. Removal

NOTE:------------------------It is advisable to loosen the track adjusting nut and the rear axle nut.

1. Remove the two front pivot shaft mounting bolts and four rear pivot shaft mounting bolts.

2. Remove the slide rail suspension assembly.

B. Inspection 1. Check to see if slide runners are worn

excessively. If the slide runner thickness is less than specified value. replace slide runner.

Wear limit: 10 mm (0.4 in) Slide runner securing screw tightening torque:

0.45 m-kg (3.3 ft-Ib)

--- - ----- - ------

1. Wear limit: 10 mm (0.4 in) 2. New: 15 mm (0.6 in)

~ -- !

2. Check the suspension wheel for damage. If damaged. replace it.

3. "DE CARBON" type shock absorber (Rear).

4-21

1981 SR540E

WARNING (Rearshock):----___. This shock absorber contains highly pressurized nitrogen gas. Read and understand the following information before handling the shock absorber. The manufacturer cannot be held responsible for property damage or personal injury that may result from improper handling. 1) Do not tamper with or attempt to

open the cylinder assembly. Injury may result.

2) Do not subject shock absorber to an open flame or other high heat. This may cause the unit to explode due to excessive gas pressure.

3) Do not deform or damage the cylinder in any way. Cylinder damage will result in poor damping performance.

4) Gas pressure must be released before disposing of the shock absorber. To do so, drill a 2 '" 3 mm (0.08 '" 0.12 in) hole through the cylinder wall at a point 1 0 '" 15 mm (0.4 '" 0.6 in) above the bottom of the cylinder.

10~ 15mm(0.4~0.6in)

2 ~ 3 mm (0.08~ 0.12 in) -r I

1981 SR540E

WARNING: -----------.., Wear eye protection to prevent eye damage from escaping gas and/or metal chips.

a. Check the rod, and if it is bent or damaged, replace the shock absorber.

b. Check for oil leakage. If oil leakage is evident. replace the shock absorber.

c. By compressing the shock absorber, check to see there is no gas leakage.

C. Slide rail suspension adjustment The setting of suspension greatly affects the stability and steering of the machine. Therefore, it is necessary to adjust the suspension setting according to course conditions and rider's driving technique.

1. Stopper band setting The height (L) of the front suspension can be properly adjusted by changing the length of the stopper band.

Standard setting: No. 1 hole from the bottom


1. Stopper band

Height Handling Track side slip

Lower Easy Increase

Higher Hard Decrease

2. Rear spring The rear spring is a determining factor in machine stability. Consider the ground surface condition

This adjustment will greatly affect the stability and handling.of the machine as well as the side slip of the track while turning a corner.

NO.5

No.4

No.3

No.2

No.l-+-o4f-STD

Performance of Bumping and Riding comfort straight running pitching

4-22

Poor More Poor

Good Less Good

and the rider's weight when setting rear springs. The suspension should be set as soft as possible, unless it impairs the stability of the machine.

1. Normal riding (less gap)

Std. weight rider

2. Trail riding (mo~e gap)

Heavy weight rider

Course or rider's

weight

Normal riding (less gap)

Std. weight rider

Rear spring set position

3. Additional wheel installaion

When the machine is driven on icy surfaces for a prolonged period of time (for instance. trail riding). additional wheels

1. Suspension wheel 2. Washer

3. Bolt

Tightening torque:

2.0 m-kg (14.5 ft-Ib)

4-23

Trail riding (more gap)

Heavy weight rider

1981 SR540E

should be installed to protect the slide runners from fast wear. This is not advisable for a race because the suspension will be adversely affected.

1981 SR540E

D. Installation Grease the slide rail suspension as indicated by arrows in the illustration.

1. Fully loosen the drive track adjusting screws.

2. Place the slide rail suspension into track and fit the forward pivot shaft using washers and bolts.

NOTE:-------------------------Install bolts finger-tight. Bolts will be tightened to proper torque when slide rail installation is complete.

3. Fit the rear pivot shaft to the frame. The rear pivot shaft is being forced toward the rear by the shock absorber. To assist in rear shaft installation. keep the shaft forward by using an iron bar.

NOTE:------------------------When installation of .slide rail is complete. tighten front and rear bolts to proper torque.

Tightening torque: Front pivot shaft mounting bolts:

6.4 m-kg (46 ft-Ib) Rear pivot shaft mounting bolts:

6.4 m-kg (46 ft-Ib)

4. Adjust the track tension by turning the track adjusting nuts. For adjustment. refer to "4-4-0. Track adjustment".

4·24

For easy installation of the slide rail suspension in the frame. proceed as folloWs .

. --- ---- -----..

4-4. DRIVE TRACK

A. Removal 1. Remove the slide rail suspension as

sembly and front axle. (See 4-1- F. Front axle and 4-3. Suspension section)

B. Inspection Check drive track and clips for cracks. damaged or wear. Replace drive track or clip as required.

c. Installation Install drive track assembly as illustrated. (See 4-1-F. Front axle and 4-3. Suspension section)

Turning direction

D. Adjustment

WARNING: ----------, A brokert track. track fittings. or debris thrown by the track could be dangerous to an operator or bystanders. Observe the following precautions: 1) Do not allow anyone to stand direct

ly behind the snowmobile when starting forward.

2) When the engine is running and the track is engaged with the snowmobile placed on its side. do not allow anyone to stand behind or on the track side of the snowmobile. The operator must stay on the seat (top side of the machine).

3) Never lift the rear of the snowmobile to allow the track to turn while the engine is running. Stop the engine and prop up the rear with a suitable stand. Never stand behind the machine when the track is spinning.

4) Never install studs (cleats) closer than three inches form the edge of the track.

5) Replace any track tha is damaged to. the depth where fabric reinforcement material is visible. Inspect track condition frequently.

The track tension should be so adjusted that when pulled at its window in the track center by a force of 10 kg (22 Ib) using a spring scale. the deflection should be as specified below.

Track deflection: 25", 30 mm/1 0 kg (0.98 '" 1.18 in/22 Ib)

25 -':':30·rnm.. ., (0.98 -1.18in»;

. ; . :~

4-25

1981 SR540E

The adjustment should be made in the following sequence:

1. Turn the track by running the engine. 2. Loosen the rear axle lock nuts. and turn

the track adjusting nuts both right and left through the track window using a box wrench to align the track with the slide rail.

NOTE:------------------------Track tension adjustment is possible without removing the split pin.

1. Rear axle nut

2. Split pin

1. Adjusting nut

3. After the adjustment specified in 2 above. pull the track window at the center of the track with a force of 1 0 kg (22 Ib) using a spring scale. The track deflection should be as specified.

4. By repeating the procedures in 1. 2 and 3 above. the track should be brought in alignment with correct tension.

5. After making sure all adjustments are correct. tighten the rear axle nut .


1981 SR540E

No good

Slide runner

Track

'-·~""~-II---<"""""--===t-_ Track metal

,> 1-.. ........ '--1H-~ __ ....... ~~-'

Forward Gap between slide runner and edge of track window.

.0-Forward

When shifted to right: Tighten the right track adjusting bolt. and loosen the left track adjusting bolt.

Good

Slide runner

4-26

Track metal

iJ,

No good

Slide runner

Forward Gap between slide runner

and edge of track window.

When shifted to left: Tighten the left track adjusting, bolt and loosen the right track adjusting bolt.

1981 SR540E

CHAPTER 5. CHASSIS

5-1. TELESCOPIC STRUT SUSPENSION .......................................................................... 5-2

A. Disassembly ........................................................................................................... 5-2

B. Inspection ............................................................................................................... 5-5

C. Installation .............................................................................................................. 5-7

5-2. FRONT SHOCK ABSORBER ("DE CARBON" TYPE) ........................................... 5-14

A. Telescopic strut suspension setting ................................................................. 5-14

5-3. "DE CARBON" TYPE SHOCK ABSORBER ............................................................ 5-18

5-4. STEERING .................................................................................................................... 5-19

A. Installation ., ......................................................................................................... 5-19

B. Adjustment ................................................................................................... ·······5-19

5-5. OIL TANK ..................................................................................................................... 5-20

5-6. FUEL TANK .................................................................................................................. 5-20

5-7. SKIS ......................................................................................................... ······················5-21

A. Inspection ............................................................................................................ 5-21

1981 SR540E

CHAPTER 5. CHASSIS

5-1. TELESCOPIC STRUCT SUSPENSION

A. Disassembly 1. Removing the ski assembly. a. Raise the snowmobile side to an

appropriate inclination.

b. Remove the split pin. c. Remove the bolt with hole.

d. Remove the ski ass·y.

2. Removing the lower end bracket.. a. Loosen the set bolt.

5-2

1. Set bolt

NOTE: -----------The set bolt needs only loosening; not removing.

b. Remove the bolt with hole from the lower front arm.

c. Loosen the lower end bracket tightening nuts.

NOTE:--------------------__ __ The nuts needs only loosening; not removing.

d. Remove the lower end bracket.

3. Removing the compression spring.

a. Remove the rubber protector.

b. Remove the 3 nuts tightening the absorber holder top.

5-3

1981 SR540E

c. Remove the 4 bolts tightening the absorber holder.

Then remove the absorber holder.

d. Remove the top one of the 2 bolts employed for double tightening.

1981 SR540E

e. Remove the bottom one of employed for double tightening.

CAUTION: ---------...... When removing the nut, hold the top of the damper sub-ass'y by spanner. Never score the rod of the damper subass'y with the pliers or the like.

5-4

f. Remove the bearing holder and collar.

g. Remove the spring seat and compression spring.

NOTE: Suspension setting can be changed by using a different compression spring.

4. Remove the damper sub-ass·y.

5. Removing the outside arm a. Remove the bolt with hole from the

upper front arm.

b. Remove the 4 panhead screws.

c. Put down the plastic hood.

d. Remove the bolt from the linkage of the outside arm.

e. Remove the circlip.

5·5

1981 SR540E

f. Remove the O-rings washers. and outside ami.

B. Inspection 1. Damper sub-ass'y a. Check the rod for scores or oil leakage

or bends. Replace as required.

b. Check the rod for an automatic return when it is pushed in and then released. Unless it returns. check the gas pressure. and adjust to the standard figure below.

Standard static pressure: 15 kg/cm2 (213 psi)

1981 SR540E

c. Check the rotor for a smooth rotation.

NOTE:--------------------__ _ The bearing has no need grease application because it is a grease-sealed one.

2. Lower end bracket Check lower end bracket for a crack. Replace as required. Check the bush for wear. Replace as required.

5·6

3. Front arm Check the bush for wear. Replace as required.

4. Outside arm Check the bush for wear. Replace as required.

5. Stopper of ski ass'y Check the rubber stopper for a crack or lack of flexibility. Replace as required.

C. Installation

Tightening torque: (1.6 m-kg, 11.6 l---r-l--$ --1

I @9 I I .~ I I ~ I I . I

J ~ I - I I

1981 SR540E

--- ~ Collar I ..".,.. ..... -'=---1 0' I -::::=====?:;,...,-~~~ I I I

I ~:

Use Lock Tight

Tightening torque: (2.1 m-kg, 15.2 ft-Ibl

5-7

I I I I F'l I

Damper t::J I

WT"'Y 'I' ! I I I I I I

: ,,~ I I I _ I L. __________ .J

Lower end Bracket

....... Greasing point

(ESSO beacon 3251

1981 SR540E

C-1. Damper sub-ass'y (Strut) Installation

1. Before inserting the damper sub-ass'y into the hole in the frame complete, make sure of the quantity of grease in the frame complete, and add grease as required.

Specified grease: ESSO beacon 325

CAUTION:------------------~

When inserting damper sub-ass'y into the frame complete, special care is required not to damage the oil seal and bushing.

5-8

2. Fit the lower seat bearing and compression spring.

Then fit the upper seat bearing with the stop bump and the collar.

3. Install the housing bearing and washer. Then tighten the nut.


4. Tighten the nut for double tightening.


5. Allow the holder bearing to be positioned in the direction as illustrated.

1981 SR540E

5-9

1981 SR540E

6. Install the absorber cover with a paper protector and tighten the 4 bolts. Then the 3 nuts on top of the absorber cover.

1. Paper protector


Put a rubber protector on the absorber cover.

5-10

C-2. Outside arm, front arm and ski compo installation

1. Before installing the O-ring, washer and circlip, apply grease to the boss on the frame complete. Then install the circlip.


2. Tighten the bolt for securing the linkage. 3. Tighten the bolts with hole to the

upper and lower front arms a. Apply grease to the collar surface and to

the lower front arm interior.


b. Be sure to install plastic washers. c. After tightening the nut, insert the split

pin; then, spread it on the end.


CAUTION:------------------~

Note that the upper and lower front arms differ in shape. Be careful not to reverse their positions. These are marked "UPPER" and "LOWER".

4. Apply grease the bracket interior for collar. Then insert the lower end bracket to the damper sub-ass'y and tighten the bolt with hole to the lower front arm, and insert the split pin.

CAUTION: ----------, Lower end brackets differ in type between the right and left. Locate the bracket with its slit outside and with its set bolt hole forward.

1981 SR540E

5-11

If! ..... I'J

7

~,(18 ~.-.J .1

a~ f3"'~ 12 ?J 0 9

R 0 o o o o

~~~

1. Lower end bracket sub-ass'y left 12. Set bolt

2. *Bracket left 13. Bolt with hole (Long)

3. *Bimetal formed bush 14. Washer

4. *Stud bolt (Short) 15. Ski complete

5. *Stud bolt (Long) 16. Collar (Long)

6. Stopper left 17. Nylonnut(10mm)

7. Lower end bracket sub-ass'y right 18. Split pin

8. * Bracket right 19. Bolt with hole (Short)

9. Stopper right 20. Plain washer (White plastic)

10. Nylon nut (8 mm) 21. Collar (Short)

11. Plain washer 22. Cap

~ ------, r ----- I . . '--3-- , "" . '~~\c13 i 3~ 2. I i l /~,~: ~Q"'~c1 I

V l I',. I 22" · , -""T" ' 20~. 'lr~ ~. 2t, i T--J 0 ~ 1 i 21 16 '~ _---~ 3: ~ . 1 ---_---, 4 ____ ~ --r~i -~ , ~ ...... c.' ............ G.~ -.... ~ "~~1~ ~-----------l· '. i 11 10

~. 10 11 'L?7~

1·~~V 17 / ~

~4~ ~. 13 ~

r 12

~ 15

..... U) CO

en ::0 U1

~ m

5. Tighten the nuts.


CAUTION: ------..,.......--~ The cap is intended to protect the rubber valve in the damper sub-ass'y. Never fail to put it on. Make sure that the cap and damper sub-ass'y are securely fitted in the bracket. Loose fit will cause the bracket to be damaged.

6. Tighten the set bolt.

CAUTION: ---------In assembly, the set bolt should be tightened at the end of assembly. Also apply a locking agent to the bolt. When disassembling, do not forget to loosen it, or the shock absorber can not be pulled out.

Specified holding agent: Nejilock super

5-13


7. Insert the stopper into the ski ass'y.

1981 SR540E

CAUTION:---------~

Note that stoppers differ in shape between the right and the left. These are marked "L" and "R".

8. Install the ski ass'y and tighten it by means of the bolt with hole. Then secure with the split pin.


CAUTION:---------_ Pay attention to the direction in installing the ski ass'y to the strut ass'y. Contact of the cap with the damper ass'y will result resistance to ski toe upand-down movement, thus making it difficult for the ski to follow the snow surface properly.

1981 SR540E

5-14

5-2. FRONT SHOCK ABSORBER ("DE CARBON" type)

A. Telescopic strut suspension setting The telescopic strut suspension setting factors can be selected from the following table according to the rider's preference.

1. Compression spring

Std. spring Optional spring

Parts No. 90501·75612 90501·70584

Spring constant 1.6 0.8 - 1.2 kg/mm (Ib/in) (89.6) (44.8 - 67.2)

Color Red No Color

2. Damper sub assembly

Std. damper sub assembly

Parts. No. 8L9·22401·00

Tension 84 ± 15 kg/0.8 m/s

Dumping (185 ± 33Ib/2.6 ft/s)

force 46 ± 5 kg/0.8 m/s Compression (101 ± 11 Ib/2.6 ft/s)

*The optional parts will be sold next December.

3. Gas pressure adjustment The gas pressure of front shock absorber can be adjusted using the special tools. By increasing the gas pressure, the initial load is increased. (The suspension becomes hard to compress but stretches· easily.) By decreasing the gas pressure, the initial load is decreased. (The suspension can contract easily but is hard to stretch.)

Maximum S.T.D. Minimum

Gas pressure 20 15 13 kg/cm2 (psi) (284) (213) (185)

(at 20°C degree)

CAUTION: ---------....., 1) Never make gas pressure checking and

adjustment under temperatures below oDe.

2) Do not use any other gas than nitrogen gas. The gas pressure should always be in specified range.

Cl :::: w u a: o LL

(!) Z Q.

:?! <{ o

Tension

1981 SR540E

- - - 13 kg/cm 2 (185 psi) -- 15 kg/cm 2 (213 psi)

- - - 20 kg/cm 2 (284 psi)

, -'~---------------:~/ -----== - =--

Compression

a. Special tools To check the nitrogen gas pressure or refill with nitrogen gas, the following tools are required. Gauge set ............. 90890-01160

CD Hose .............. 90890-01158 @ Joint gauge ......... 90890-01161 @ Joint holder ........ 90890-01162 @ Joint hose end ...... 90890-01163 @ Joint cover ......... 90890-01164 ® Needle ............ 90890-01167 (j) Check gauge ........ 90890-03063 ® Joint .............. 90890-01165

5-15

Stroke: 100 mm (3.93 in) Speed: 288 rpm

b. Checking nitrogen gas pressure

NOTE:------------Oil the injection needle before inserting it in the Gas adjustment valve.

To check the nitrogen gas pressure in the gas chamber, use the check gauge. To measure the gas pressure, and insert the oiled needle into the gas chamber.

1981 SR540E

c. Refilling nitrogen gas To refill with nitrogen gas, proceed as

follows:

1) Fit the injector needle onto the nitrogen

pressure hose and oil the injector needle

lightly. 2) Close the regulator off completely by

turning the knob in a counterclockwise

direction. Open the nitrogen bottle main

valve. 3) Insert the injector into the rubber valve

in the housing cap.

NOTE:------------------------Support the injector needle with your hand

during pressurization.

5-16

4) Adjust the gas pressure to a desired

value. Hold this pressure for one minute.

Maximum static pressure: 20 kg/cm2 (284 psi)

CAUTION:------------------~

Do not over-pressurize the gas chamber. Gradually increase the regulator setting until the required pressure is reached.

5) Close the nitrogen bottle main valve and

remove the injector needle, from the

housing cap. This will allow the nitrogen

pressure in the hose to flow out. Back

off the pressure regulator.

d. Bleeding nitrogen gas To bleed the nitrogen gas, oil the injector

(needle) and thrust it into the housing

cap. The gas can easily be bled.

NOTE:--------------1. After nitrogen gas refilling or bleeding,

screw in the joint cover over the check

gauge. 2. When using the check gauge to verify the

nitrogen pressure, approximately 0.351

kg/cm2 will be lost. Do not use the

regulator pressure gauge to check the

pressure in the unit.

3. Take care not to damage nitrogen gas

needle during insertion. Replace safety

sheave when needle is not in use.

4. As the suspension is used, it will heat up, thus increasing the nitrogen gas pres

sure. It is recommended that gas pressure

be adjusted and check at room tempera

ture so consistant results can be achieved.

Joint ----____.

r---- Input pressure indicator

r----Cylinder pressure indicator

r---Valve (1)

Valve (2) -----H"---~ Nitrogen cylinder

Hose------"<"

Injector (Oil before inserting) ------,

4. Damper unit pressure adjustment in a snowmobile.

1. Removing the ski assembly a. Raise the snowmobile side to an

appropriate inclination. b. Remove the split pin. c. Remove the bolt with hole.

d. Remove the ski assembly.

5-17

2. Gas pressure adjustment a. Refilling nitrogeen gas.

1981 SR540E

1981 SR540E

NOTE:-----------------------Gas pressure adjustment is possible on the damper sub-assembly and lower end bracket without removing them.

1. Damper sub-assembly·· 2. Cap 3. Lower end bracket

b. Checking nitrogen gas pressure.

NOTE:------------------------After refilling the nitrogen gas. it is not necessary to check the pressure.

c. Releasing nitrogen gas.

Nitrogen gas refilling. releasing. or checking should be done on minimum necessary occasions; otherwise. it may damage the rubber valve with the consequent pressure leakage.

5-18

5-3. "DE CARTON" TYPE SHOCK ABSORBER

WAR N ING: -----------, This shock absorber contains highpressure nitrogen gas. To prevent the danger of explosion. read and unders-. tand the following information before handling the shock absorber. The manufacturer can not be held responsible for property damage or personal injury that may result from improper handling. 1. Never tamper or attempt to disas

semble the cylinder. 2. N ever throw the shock absorber into

an open flame or other high heat. The shock absorber may explode as a result of nitrogen gas expansion.

3. Take care not to scratch the contact surface of the piston rod with the cylinder; or oil could leak out. Do not deform or damage the cylinder in any way. Cylinder damage will result in poor damping performance.

4. Never attempt to remove tthe plug at the bottom of the cylinder. It is very dangerous to remove the plug.

5. When scrapping the shock absorber. follow the instructions on disposal.

Notes on disposal Before disposing the shock absorber. be sure to extract the nitrogen gas. In the case of rear shock absorber. drill a 2 ,...., 3 mm (0.08 ,...., 0.12 in) hole through the cylinder at a position 10,...., 15 mm (0.4 ,...., 0.6 in) from the bottom of the cylinder. The front shock absorber is chromed. Remove this chrome deposit from the absorber before drilling a hole in it. The drilling should be done in the groove as illustrated. At this time. wear eye protection to prevent eye damage from escaping gas and/or metal chips.

1 0 ~ 15 mm (0.4 ~ 0.6 in)

2 ~ 3 mm (0.08 ~ 0.12 in)

Rear shock absorber

.....

~ [JJ L

Front shock absorber

5-4. STEERING

A. Installation 1. Secure the steering relay rod (with un

iversal joint attached) to the outside arm with the flange nut and cotter pin.


2. Install the steering column on the frame. Before this operation, coat the steering lower and upper bearing with grease. Tighten the nuts and bolts, and bend the lock washer tab.

1981 SR540E


3. Connect the steering relay rod to the steering column using the flange nut. Install a new cotter pin.


B. Adjustment 1. Ski

Hold the handlebar straight and check to see that the skis are parallel. If not, loosen the steering relay rod lock nut. and by turning the steering relay rod in or out. adjust the ski toe-out to specifi

cation (see below).

Ski stance: 880 mm (34.6 in) Ski toe-out: 0 mm (O in)

Steering relay rod tightening torque: 4.7 m-kg (34 ft-Ib)

1981 SR540E

11 Front

A--I-.

1. Ski spindle center A - C = 0 mm (0 in) B. Ski width

5·20

5-5. OIL TANK

1. Check the hose from the tank to the oil pump for obstructions such as pinching or other damage.

2. It is advisable that the oil filter be replaced with a new one each season.

1. Oil filter

5-6. FUEL TANK

1. Check for missing pipe retaining dips. 2. Check pipes for flattening caused by

tank. 3. Check the breather pipe for correct

routing. Check clamps for looseness. The breather pipe should be routed so that no fuel leakage will result from severe vibration. shock and/or banking of the vehicle. For routing. refer to piping and wiring diagrams.

4. It is advisable that the fuel filter be replaced with a new one each season. If the filter is faulty (obstructing the fuel flow or having a breakage in the element). it should be replaced as an assembly unit.

1. Fuel filter

2. Steering handlebar adjustment By loosening the bolt securing the handlebars, the height of handlebars can be adjusted to suit the rider's preference. After adjustment. be sure to tighten the bolts.

WARNING: ----------, Tighten the bolts alternately to maintain a parallel gap as illustrated. (1.5 mm for front and 3.5 mm for rear)


1. Holder 2. Handlebar

5-21

1981 SR540E

5-7. SKIS

A. Inspection Check the ski runner. if worn excessively, replace.

1981 SR540E

CHAPTER 6. ELECTRICAL

6-1. IGNITION SYSTEM ...................................................................................................... 6-2

A. Circuit diagram ..................................................................................................... 6-2

B. Troubleshooting ................................................................................................... 6-2

C. Ignition timing ...................................................................................................... 6-3

D. Spark gap test ....................................................................................................... 6-4

E. Ignition coil ............................................................................................................ 6-5

F. Spark plug ............................................................................................................. 6-5

G. Pulser and charging coils test ............................................................................ 6-6

H. C.D.I. unit ............................................................................................................... 6-7

6-2. LIGHTING SYSTEM ..................................................................................................... 6-7

A. Circuit diagram ..................................................................................................... 6-7

B. Headlight beam adjustment ............................................................................... 6-7

C. Lighting coil test ................................................................................................... 6-7

D. Voltage regulator. ................................................................................................. 6-9

E. Oil caution switch .............................................................................................. 6-10

1981 SR540E

CHAPTER 6. ELECTRICAL

6-1. IGNITION SYSTEM

A. Circuit diagram

® ~------------------~ ~--------~

111 1. C.D.I. magneto 4. C.D.I. unit 7. Engine stop switch 2. Pulser coil 5. Main switch 8. Ignition coil 3. Charging coil 6. Tether switch 9. Spark plug

B. Troubleshooting No spark is produced or weak.

'---_C_h_e_c_k---,o,f_c_o_n_n_e_c_ti_o_n_s---'I ................. Check lead wire connections or short circuits

I ~ OK Faulty--------tl Correct.

'---_S_p_a r_k_t-r;I-_s~t~~_I._ .. _" '_"_" _" ._ .. _ ... _. '_"_" '_"_"_" ._,,_,,_. s_e_e_6-,- 1 -D. "Spa rk gap test" I ~ No spark Spark-------tl Plug is faulty .

........................... Measure coil resistance. '-------~~------~

(See 6-1-G. "Pulser and charging coil test")

OK Fa u Ity --------------.1 Replace .

............................. Measure coil resistance. ~----~~----~

OK

.J.

(See 6-1-G. "Pulser and charging coil test")

Faulty----------+I Replace .

6·2

11

.......................... Ignition coil test (See 6-1-E. "Ignition coil")

OK Faulty , Replace.

,--C_._D_.I_. U"""T~_it----JI ...................................... see 6-1-H. "C.D.I. unit"

l Faulty , Replace

The engine starts but will not pick up speed.

Spark plug 1 .................................... Clean or replace (See 6-1-F. "Spark plug")

I OK

........................... Make continuity test '-----.-----' (See 6-1-G. "Pulser and charging coil test")

OK

'--__ -.-_____ --' .................. (See 6-1-C. "Ignition timing)

...................................... (See 6-1-H. "C.D.I. unit") '----~--'

'--------------+ Faulty ---------., Replace.

C. Ignition timing 1. Remove the fan case cap. 2. Remove the right side spark plug and

screw dial gauge stand into spark plug hole.

Tool name Tool No.

Dial gauge stand 90890-01195

3. Insert dial gauge with needle into stand.

Tool name

1981 SR540E

Tool No.

Dial gauge 90890-01252 4. Rotate magneto flywheel until piston is

at top-dead-center (T.D.C.) Dial gauge needle 90890-03098

6-3

Set the zero on dial gauge face to line up exactly with a dial gauge needle. Tighten set screw on dial gauge stand to secure dial gauge assembly. Rotate flywheel back and forth to be sure that indicator needle does not go past zero.

\1981 SR540E

5. Starting at T.D.C., rotate flywheel counterclockwise until dial gauge reads approximately 3-1/2 needle revolutions before-top-dead-center (B.T.D.C.).

6. Slowly turn flywheel clockwise until dial gauge reads specified ignition timing.

Ignition timing (B.T.D.C.) 1.5 ± 0.1 mm (0.059 ± 0.004 in)

7. Check the marks on flywheel and base for alignment. If not aligned, adjust ignition timing as follows.

a. Remove the manual starter assembly. b. Remove the starter pulley and drive fan

pulley. (Refer to "2-1-0 Cooling fan") c. Loosen the base set screws and turn

the base assembly until mark alignment is achieved.

d. Tighten base set screw.


6-4

e. Install the drive fan pulley and starter pulley. (See "2-2-F-2. Cooling fan installation")

f. Install the starter assembly. (Refer to "2-2-G. Starter")

8. Remove the dial gauge and stand.Replace the spark plug and fan case cap.

Spark plug tightening torque: 2.8 m-kg (20 ft-Ib)

NOTE:------------------------The timing light should be used to check if the marks on the rotor and base are aligned when both are replaced with new ones. The marks should align at any specified timing.

D. Spark gap test The entire ignition system can be checked for misfire and weak spark using the Electro Tester. If the ignition system will fire across a sufficient gap, the engine ignition system can be considered good. If not, proceed with individual component test until the problem is found.

1. Warm up engine thoroughly so that all electrical components are at operating temperature.

2. Stop engine and connect tester as shown.

GEB +

CD

1. Electro-Tester 2. Plug wire from coil

3. Spark plug

3. Start engine and increase spark gap until misfire occurs.

Minimum spark gap: 6 mm (0.24 in)

E. Ignition coil 1. Coil spark gap test a. Remove the ignition coil from frame. b. Connect Electro Tester as shown. c. Connect fully charged battery to tester. d. Turn on spark gap switch and increase

gap until misfire occurs.

Minimum spark gap: 6 mm (0.24 in)

1. Battery 2. 6 mm (0.24 in)

2. Coil winding resistance tests Use a pocket tester or equivalent ohmmeter to determine resistance and continuity of primary and secondary coil windings.

Manufacturer Primary coild Secondary coil resistance resistance

Hitachi 0.15H ± 10% 3.6kH ± 20% (CM62-20) at 20°C (68°F) at 20°C (68° F)

Toyo Denso 0.12H ± 10% 4.0kU ± 20% (YW-51 ) at 20°C (68° F) at 20°C (68°F)

6-5

1981 SR540E

- Primary coil resistance

---- Secondary coil resistance

F. Spark plug The life of a spark plug and its discoloring vary according to the habits of the rider. At each periodic inspection. replace burned or fouled plug with suitable one. Suitability may be determined by asking the rider how long and how fast he rides. Recommend a hot. standard. or cold plug type accordingly. It is actually economical to install a new plug often since it will tend to keep the engine in good condition and prevent excessive fuel consu mption.

1. How to "read" spark plug (condition) (The spark plug color samples are at the end of this manual)

CD Good The insulator normally has a tan color. This check should be made after driving the machine over a long distance: otherwise. the correct reading of the spark plug will be impossible.

® Bad (Mixture is too rich or spark plug temperature is low). If mixture are too rich. the metal shell end will be wet as shown in the photo. acceleration or high-speed performance will be poor. If the spark plug temperature is low. the phenomenon specified in above will not take place. As shown in the photo. the insulator is dark and sooty.

@ Bad (Mixture is too lean or spark plug temperature is high.) The insulator is roughened (lower photo) or burned white (upper photo). and the ground electrode is green due to oxidation. This state of the spark plug

1981 SR540E

will result in premature ignition or power loss.

@ Bad (Piston holed or seized) The metal shell end and insulator show signs of overheating. If mixture is too lean. the piston can be holed or the engine may tend to knock. As a result. the spark plug will have occasional aluminum deposits.

® Bad (Knocking) Generally. the spark plug will not be greatly affected by the strength of mixtures; so long as the distance travelled is not long. But after long hours of driving. the insulator takes a greyish black color due to aluminum deposits. If so. the engine will fail to deliver full power. and the piston could be holed or seized. As a preventive measure. it is recommended to use a higher octane gasoline. adjust the ignition timing. enrich the mixture or remove the carbon in the cylinder.

@ Bad (Melting) If the spark plug overheats. electrodes will met away or the piston will be holed.

2. Inspection Instruct the rider to:

a. Inspect the clean the spark plug every 400 km (250 mi) or 20 hours.

1. Yellow 3. Black

2. Brown 4. Blue

b. Clean the electrodes of carbon and adjust the electrode gap.

c. Be sure to use the proper reach plug as a replacement to avoid overheating. fouling or piston damage.

Spark plug type: BR9EV (NGK)

Spark plug gap (use wire gap gauge): 0.7 '" 0.8 mm (0.028 '" 0.031 in)

Spark plug torque: 2.8 m-kg (20 ft-Ib)

G. Pulser and charging coil test Check the resistance between terminals. If resistance is out of specification. coil is broken. Check the coil connections. If the coil connections are good. then the coil is broken inside and it should be replaced.

Charging coil resistance: Black to Brown leads:

350n ± 10% at 20°C (68 0 F)

Black to Blue leads: 15.0n ± 10% at 20°C (68 0 F)

Pulser coil resistance: Black to White/Red leads:

9.0n ± 10%at20°C(68°F)

5. White/Red 7. Pocket tester 6. Flywheel magneto 8. Set tester at "RX1" position

6-6

H. C.D.I. unit In case of ignition failure with all the above system check-ups proving in good order, replace the C.D.I. unit assembly.

6-2. LIGHTING SYSTEM

A. Circuit diagram

1. Flywheel magneto 5. Meter light 2. Lighting source coil 6. Taillight 3. Voltage regulator 7. Brake light 4. Headlight

B. Headlight beam adjustment 1. Inspection

Check the headlight beam direction. The high beam must be directed downward at an angle of 1/2 0 to the horizontal line.

6-7

1981 SR540E

~--------~Q------------~

Horizontal line

h

Q 3.0m(10ft) 7.6 m (25 tt)

h 26 mm (1.0 in) 66 mm (2.6 in)

2. Adjustment When necessary, adjust headlight beam by tightening or loosing the four headlight mounting screws.

C. Lighting coil test Check the resistance between yellow lead and ground. If resistance is out of specification, coil is broken. Check the coil connections. If the coil connections are good, then the coil is broken inside and it should be replaced.

Lighting coil resistance: Black to Yellow leads:

0.1911 ± 1 0%/20°C (68 0 F)

1981 SR540E

1. Yellow 3. Black 2. Brown 4. Blue

D. Voltage regulator

1. Instruments required for inspection CD Regulator checker. ® Two 12V batteries. @ Sub lead wire.

5. White/Red 7. Pocket tester

6. Flywheel magneto 8. Set tester at .. RX'" position

@

2. Connections

6-8

Connect two 12V batteries in series using the sublead wires. Connect the red lead wire (A) (for power) of the regulator checker to the positive side of one of the batteries. and connect the bl'ack lead wire (8) to the negative side of the other battery.

Connect the red lead wire (C) (for test) of the regulator to the regulator case. and connect the black lead wire (0) to the lead wire of the regulator.

3. Inspection Checking the battery voltage First. set the switches. both right and left. to "12V" "Va LT". If the checker needle points to 20 volts or more. the battery voltage is sufficient.

4. Checking the regulator a. Set the right switch to "REG". If the

lamp lights up. there is continuity in the regulator checker.

b. Operation test Slowly slide the switch to the right. If the needle quickly swings back to O. the moment that it moves into the black zone of the scale. the working voltage of the thyristor in the regulator is in good condition. and the regulator is also in good condition.

6-9

1981 SR54Q.E:

Thyristor working voltage: 13.8 ± 0.5 volts at 5.000 r/min

If the regulator is faulty: The checker needle swings over the black zone. and it will not return to 0 from 20V or more.

E. Oil caution switch The oil caution light comes on when there is little oil in the oil tank. thus warning the rider. The oil caution circuiut can be checked by squeezing the brake lever.

1. Flywheel magneto

2. Brake switch

3. Oil caution switch ass·y

4. Diode

@ ,----I ® I I I

G/yl ® I L ___ _

G ---..,

___ ..J

BIR (j)

5. Oil level switch

6. Brake light

7. Oil caution light

1981 SR540E

1. Oil level switch check a. Connect the pocket tester leads to the

oil caution switch ass'y lead connector

Pocket tester (-) +----+ Green lead Pocket tester ( + ) +----+ Black/Red

b. Side the switch float. When the float is

Pocket tester connecting point

(+) (-)

Red Black

Lead wire Black/Red Green/Yellow color ----------.- -------------

Green/Yellow Black/Red

Black/Red Green ------------- --------------

Green Black/Red

0: Continuity

x : Discontinuity

NOTE:------------------------When making this testing. the switch float must be moved down to the bottom end of the slider. (switch ON position)

moved down to the bottom end of the slider. the tester should read zero. If not. the switch must be replaced.

2. Diode check Check the diode as specified using the pocket tester.

Replace Replace

Good (element (element

shorted) opened)

0 0 x ------------- ------------.--- ----------------

x 0 x

0 0 x --------------- ------------ ---- -----.------

x 0 x

6-10

1981 SR540E

CHAPTER 7. APPENDIX

7-1. SPECIAL TOOLS ........................................................................................................... 7-2

7-2. SPECiFiCATIONS ......................................................................................................... 7-3

A. General .................................................................................................................. 7-3

B. Engine .................................................................................................................... 7-3

C. Drive and track suspension ................................................................................ 7-5

D. Chassis ................................................................................................................... 7-5

E. Electrical ................................................................................................................ 7-6

F. Tightening torque ................................................................................................. 7-7

7-3. WIRING DIAGRAM ..................................................................................................... 7-9

7-4. WIRE AND PIPE ROUTING DIAGRAM ................................................................. 7-10

1981 SR540E

CHAPTER 7. APPENDIX

7-1. SPECIAL TOOLS

1. 4-b, 5.. . ...

~ ...•. ~.

3.

7

No. Description Tool No.

1 Dial gauge 90890-03097

" 2 Dial gauge stand No.2 90890-01195

3 Dial gauge needle (56 mm) 90890-03098

4-a Flywheel puller attachment 90890-01803

4-b Flywheel puller attachment 90890-01804

4-c Flywheel puller screw 90890-01906

4-d Drive handle 90890-01817

4-e Flywheel puller body 90890-01848

5 Rotor holding tool 90890-01235

6-a Primary fixed sheave puller (M 18) 90890-01898 iTSL-90018-81-01

6-b Primary fixed sheave puller (M20) 90890-01897 IT TSL-90018-59-02

6-c Primary fixed sheave puller

90890-01899 attachment 14.

7 Sheave sub-assembly tool 90890-01858

8 Bushing tool 90890-01883

9 Sheave gauge 90890-01702

10 Pocket tester 90890-03104

11 Electro tester 90890-03021

12 A.C. Regulator checker 90890-03090

13 Sheave holder 90890-01701 TSL-90018-80-00

14 Eccentric bearing installer 90B90-0 1851

7-2

1981 SR540E

7-2. SPECIFICATIONS

A. General

Model SR540E

Model: Model (I.B.M. No.) SR540E (8l9)

Frame 1.0. & starting number 8l9-016101

Engine 1.0. & starting number SA535-016101

Dimension: Overall leng-th 2,610 mm (102.7 in)

Overall width (std) 1,080 mm (42.5 in)

Overall height (w/windshield) 970 mm (38.2 in)

B. Engine

Description: Engine type Axial fan cooled two-stroke, torque

induction, twin cylinders

Engine model SA535 Displacement 535 cc (32.65 cu.in)

Bme x Stroke 73 x 64 mm (2.874 x 2.52 in) Effective compression ratio 6.0: 1 Starting system Recoil hand starter

Ignition system C.D.I. lubrication system "Autolube" oil injection

Cylinder head:

Combustion chamber volume (with spark plug) 27.5 cc (1.68 cu.in)

Compression chamber type Dome + Squish Head gasket thickness x Q'ty 0.5 mm (0.02 in) x 1 pc.

Cylinder:

Material Cast iron sleeves aluminum

Bore size 73 mm (2.874 in)

Taper limit 0.05 mm (0.0020 in)

Out of round limit 0.01 mm (0.0004 in)

Piston: Piston skirt clearance (measuring point) 0.055 ~ 0.060 mm (0.0022 ~ 0.0024 in)

(17 mm from piston skirt end)

Piston oversize 1 st 73.25 mm (2.884 in)

2nd 73.50 mm (2.894 in)

3rd 73.75 mm (2.904 in)

4th 74.00 mm (2.913 in)

Piston pin outside diameter x length 4>20 x 56 mm (4)0.787 x 2.20 in)

Piston ring: Piston ring design (Top) Keystone Piston ring design (2nd) Keystone Ring end gap (installed) 0.30 ~ 0.50 mm (0.012 ~ 0.020 in)

Small end bearing:

Type Needle bearing

Big end bearing:

Type Needle bearing

Crankshaft: Crankshaft assembly width (A) 200 ± 0.25 mm (7.87 ± 0.010 in)

7-3

1981 SR540E

Crankshaft assembly width (F) +0 ( +0 .) 60 -0.05 mm 2.362 -0.002 In

Crankshaft deflection (D) 0.03 mm (0-1) 0.04 mm (0-2)

0.04 mm (0-3) 0.05 mm (0-4) Connecting rod big end side clearance (C) 0.25 ~ 0.75 mm (0.010 ~ 0.030 in)

Connecting rod small end deflection (P) 2.0 mm (0.079 in)

-jf-p

Q

I J

lI~A~" Crank pin outside diameter x length 1/>24 x 59 mm (1/>0.945 x 2.323 in) Crank pin type Solid shaft assembly type with serration Crank bearing type (left) x q'ty #6306 special x 2 pcs. Crank bearing type (Center) x q'ty #6206 special x 2 pcs. Crank bearing type (Right) x q'ty #6206 special x 1 pc. Crank oil seal type (left) x q'ty FWJ-3278 9.5 TS x 1 pc. Crank oil seal type (Center) x q'ty labyrinth seal x 1 pc. Crank oil seal type (Right) x q'ty FWJ-3248 10-1 TS x 1 pc.

Cooling fan: Fan belt tension 4 ~ 6 kg/8 mm (8.8 ~ 13.2 Ib/0.31 in)

Carburetor: Type & manufacturer/quantity B044-38/KEIHIN/1 pc. 1.0. Mark 81900 Main jet (M.J.) #150 Main air jet (MAJ.) #180 Power jet (Pw.J.) #150 Power air jet (Pw.A.J.) #170 Slow jet (S.J.) #92 Slow air jet (SAJ.) #100 Pilot screw (P.S.) 2-1/4 turns out Starter jet (St.J.) #160

Float height 15 +2 mm (0.59 +0.08 in) -3 -0.12

Idling engine speed 1500 r/min

[Main jet setting chart]

~ -30°C -20°C -lOoC O°C lOoc 20°C

Altitude (-22°F) (-4°F) (14°F) (32°F) (50°F) (68°F)

.. #150 .. Se.llevel

-(#155) - _#145 ___

.. #150 .. - 600 m (2000 tt) -#155 .- · #145 -

- #145 .. - 1200 m (4000 It) -#150 - .. #140 · - #140 . - 1800 m (6000 It) -#145 - · #135 ·

#135 . - 2400 m (8000 It) -#140 - · #130 -- #130 . - 3000 m (10000 tt) -#135 - - #125 ·

7-4

Intake reed valve: Type

Bending limit Valve lift

Lubrication:

Autolobe pump-Color code Autolube pump-Minimum stroke Autolube pump-Maximum stroke

Autolube pump-Reduction ratio

Autolube pump-Output Min./200 strokes

Autolube pump-Output Max./200 strokes Autolube pump wire free play

Oil tank capacity

Oil grade

C. Drive and track suspension

Transmission: Type

Drive ratio Engagement rpm

Primary spring:

Part No. Color code

Secondary spring:

Part No. Color code

Secondary spring pre-load (twist)

Sheave distance

Sheave off-set

V-belt width and outer line length V-belt wear limit

Track suspension:

Type Damper type

Spring color code (Front)

Spring color code (Rear)

.Slide runner wear limit Track width

Track deflection Length on ground

Wheel sprocket matenal and number of teeth

Stopper band length

Secondary drive:

Type

Reduction ratio Chain pitch x Number of links

Free play

Chain housing oil quantity Chain housing oil grade

Brake:

Type Brake pad thickness Brake pad wear limit Brake cable "L" distance

Clearance between lining pad and disc

7-5

V type 0.6 mm (0.024 in)

9.7 mm (0.38 in)

Pink 0.20 ~ 0.25 mm (0.0079 ~ 0.0098 in) 1.65 ~ 1.87 mm (0.0650 ~ 0.0736 in)

1/40 0.95 ~ 1.19 cc (0.0321 ~ 0.0402 oz) 7 .84 ~ 8.89 CG (0.2651 ~ 0.3006 oz)

25 ± 1 mm (0.98 ± 0.04 in) at idle 2.5 Liter (2.6 US.qt)

YAMALUBE 2-cycle

V-belt automatic centrifugal engagement 3.5: 1 ~ 1 : 1 3400 ~ 3800 r/min

90501-50500

Red

210" (No.3 hole) 90508-45286

Yellow 180 0 (No.2 hole)

+0 +0 . 270 -3 mm (10.63 -011 In)

11 ± 0.5 mm (0.433 ± 0.020 in)

31.6 x 1.099 mm (1.24 x 43.3 in) 26 mm (1.02 in)

Slide rail suspension

Oil and gas damper Red-Green

No painted 10 mm (0.394 in) 381 mm(15in)

25 ~ 30 mm/l 0 kg (0.98 ~ 1.18 in/22 Ib) 942 mm (37.1 in)

Double Polyethylene. 9 teeth

220 mm (8.66 in) (No.1 hole from the bottom)

Chain (#35K-3)

17/31 (1 : 1.824)

9.525 mm (0.375 in) x 66L + 5 +0.2 .

10 -2 mm (0.4 -008 In)

250 cc (8.5 oz)

Gear oil API "GL-3" (SAE #75 or 80)

Floating disc type

13.5 mm (0.53 in) 9.5 mm (0.37 in) 57 mm (2.24 in)

0.15 mm ~ 0.3 mm (0.006 ~ 0.012 in)

1981 SR540E

1981 SR540E

D. Chassis

Frame: Material Aluminum + Steel

Steering system: Caster (ski column) 25°

Camber 0° Ski length x width x thickness 980 x 120 x 2 mm (~8.6 x 4.7 x 0.08 in) Ski stance 880 mm (34.6 in) Ski toe-out Omm(Oin) Steering linkage type Tie-rod Lock to lock angle (Ski) Right ski, L: 27.9° R: 33.4°

Left ski. L: 33.4° R: 27.9° Steering angle Right: 46°

Left: 46°

Front suspension: Type (YAMAHA T.S. SUSPENSION) Coil spring Damper type Oil and gas damper

Fuel tank: Capacity 26.6 Liter (7.0 US gal.) Fuel grade Regular gasoline

E. Electrical

Ignition system: Type-flywheel magneto (C.D.I. Type)

Model/Manufacturer F3T352/MITSUBISHI Voltage 12V Pulser coil resistance 9.0n ± 10% at 20°C (68°F) (White/Red-Black) Charging coil resistance 350n ± 10% at 20°C (68° F) (Brown-Black) Charging coil resistance 15.0U ± 10% at 20°C (68° F) (Blue-Black)

Ignition timing: B.T.D.C. 1.5 mm (0.059 in)

Ignition coil: HITACHI : TOYO-DENSO Manufacturer/Model/Quantity CM62-20/1 pc. : YW-51/1 pc. Spark gap 9 mm (0.4 in)/300 r/min. :.

11 mm (0.6 in)/3,OOO r/min.' • Primary winding resistance 0.1 5U ± 1 0% at 0.12U ± 10% at .

20°C (68°F) 20°C (68°F) Secondary winding resistance 3.6kU ± 20% at 4.0kU ± 20% at

20°C (68°F) 20°C (68°F) Diode (Yes or No) No •

Spark plug: Type & quality NGK BR9EV x 2 pcs. Spark plug gap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)

Spark plug cap: Type Resign type with noise suppressor Noise suppressor resistance 5kn ± 25% at 20°C (68°F)

C.D.I. unit: Model/Manufacturer 8H4-20/MITSU BISH I

Lighting system: Lighting output 12V-l00W Lighting coil resistance 0.19n ± 10% at 20°C (68° F) (Yellow-Black) Headlight type Halogen light

Bulb wattage/q'ty 12V-60/55W x 1 pc. Tail/Brake light wattage 12V-8W/23W

7-6

1981 SR540E

A.C. regulator:

Model/Manufacturer Voltage

TRIZ-24B HITACH or SB5 16B TOSHIBA

13.B ± 0.5V

F. Tightening torque

Part to be tightened

[Engine)

Spark plug

Cylinder head Cylinder

Flywheel magneto

Crankcase upper and lower

Tightening sequence

Thread size

M14Pl.25

MB Pl.25 MB Pl.25

M16Pl.0

MB Pl.25

M6 Pl.0

Tightening torque

2.B m-kg (20 ft-Ib)

2.5 m-kg) lB ft-Ib) 2.5 m-kg (lB ft-Ib)

7.3 m-kg (53 ft-Ib)

First: 1.0 m-kg (7 ft-Ib)

Final: 2.0 m-kg (15 ft-Ib) First: 0.5 m-kg (3.5 ft-Ib)

Final: 1.0 m-kg (7 ft-Ib)

,-----1/-;----:------' -

ft6_~~2 .. "'0. __ ~~_$-5 1° 4+ i9

Ring weight and stay Flywheel magneto and stay

Fan shaft and pulley 2

Starter pulley

Crankcase and engine bracket

[Drive and track suspension)

Primary sliding sheave and cap

Installation of primary sheve

Installation of secondary sheave Bearing housing

Brake caliper and housing chain

Installation of drive chain sprocket Installation of driven chain sprocket

Chain housing and frame Installation of front axle L. H.

Front axle housing and frame Wheel sprocket and front axle Front pivot shaft

Rear pivot shaft

Rear axle Sliding runner

[Chassis)

Engine mounting bolt Steering column and gate

Steering gate

Steering relay rod adjusting nut Steering lower bracket

Installation of steering column 1.2

M6 Pl.0

MB Pl.O M16Pl.0

MB Pl.25 MB Pl.25

M6 Pl.O

UNF 1/2"

M14Pl.5 MB Pl.25

M10P1.25

M14Pl.5

M10P1.25 MB Pl.25 M22 Pl.0

MB Pl.25

M6 Pl.0 M10P1.25

Ml0 P l.25 M12 Pl.25

M6 Pl.O

M10P1.25

M8 Pl.25

MB Pl.25 Ml0Pl.25 MB Pl.25

MB Pl.25

7-7

I 11

1.0 m-kg (7.2 ft-Ib)

1.5 m-kg (1 O.B ft-Ib) 4.3 m-kg (31.1 ft-Ib)

2.3 m-kg (16.5 ft-Ib) 2.3 m-kg (16.5 ft-Ib)

1.1 m-kg (B ft-Ib)

Initial: 12 m-kg (B7 ft-Ib)

Loosen once and retighten: 6.5 m-kg (47 ft-Ib) 6.4 m-kg (46 ft-Ib) 2.3 m-kg (16.5 ft-Ib)

4.B m-kg (35 ft-Ib)

6.0 m-kg (43.5 ft-Ib) 4.B m-kg (35 ft-Ib)

2.3 m-kg (16.5 ft-Ib)

B.5 m-kg (61.5 ft-Ib) 2.3 m-kg (16.5 ft-Ib)

0.55 m-kg (4 ft-Ib) 6.4 m-kg (46 ft-Ib)

6.4 m-kg (46 ft-Ib)

B.O m-kg (5B ft-Ib) 0.45 m-kg (3.3 ft-Ib)

5.2 m-kg (37.6 ft-Ib)

2.3 m-kg (16.5 ft-Ib)

1.4 m-kg (10 ft-Ib) 4.7 m-kg (34 ft-Ib) 2.3 m-kg (16.5 ft-Ib)

1.45 m-kg (10.5 ft-Ib)

Remarks

Use Neji lock (Adhesive) Use Neji lock (Adhesive)

Use motor oil

Use lock washer

Use lock washer

1981 SR540E

Steering relay ass'y M10Pl.25 4.7 m-kg (34 ft-Ib) Use cotter pin

Front shock absorber and bracket M8 P1.25 2.1 m-kg (15.2 ft-Ib)

Bracket 1. 2 set bolt M6 Pl.0 0.2 m-kg (1.4 ft-Ib)

Front arm Ml0Pl.25 1.6 m-kg (11.6 ft-Ib) Ski installation Ml0 P1.25 4.3 m-kg (31. ; ft-Ib)

7-8

Headlight (12V 60W/55W)

01

'-I cO LIGI VI

GIG.yI~

r=±1-t

0.1 level switch

~ §.

__ I

LI B

VI B,

'--+-+'

~ ~ L

Voltaglf regulator

1.

@ C.D.I. magneto

...&..

BIW

L IBr"l B

C.D.I. unit

Color code

L. ............ Blue y ............. yellow

o ............ Orange G ............ Green

Br ........... Brown

Gy .......... Gray

o o '"--'"

Ignition coil

L.

R ............. Red

B ............ Black

G/y ........ Green/yellow

B/R ........ Black/Red

B/W ...... Black/White

W/R ....... White/Red

..., I

W

~ Spark plug

~

..... <0 00

C/)

:I:1 U1

~ m

Main switch lead

Tai! Ilgl'lt lead

Olile-ve! gauge

Details of wire harness routing

Engme stop switch lead

/ MeIer assembly lead

/ ~ Head l\ghtbeam sWitch lead

~ht'w"'hl"d Tether SWItch I~ad

Fuel pipe

Fuel tank breather pipe

Fuel pump

carburetor

Fuel deJlvery plpe

Details of fuel pipe routing

SR540E RACING TIPS

Testing in Alaska has yielded the following pro-stock racing specifications and adjustments for the SR540E. Yamaha has found that these recommendations produce the best performance under specific test conditions. Different local conditions, however, may require different settings. Use these recommendations as a guide, not hard and fast rules. Always tune your machine to suit the particular conditions of each race.

ENGINE AND CLUTCH

See technical bulletin S80-012 for standard specifications.

CARBURETOR TUNING

The standard 150 main jet is too rich (especially for the left-side cylinder) even at sea level. Reduce the main jet size to get good plug color at full throttle. As you reduce the main jet, the right-side cylinder will not change, but the left-side cylinder will become more and more lean until it matches the temperature of the right-side cylinder.

CLUTCH TUNING

1. Primary Spring

Standard First Option Second Option

90501-50500-00 90501-55456-00 9050 1-55241-00 Red Silver-White Red-Pink 25 x 1.4 kg/mm 30 x 2.0 kg/mm 35 x 1.75 kg/mm

2. Clutch Weights

Select the rivet quantity and location to maintain a 7100 rv 7200 shift rpm.

3. Secondary Settings

Hole #3 (210°)

or

Stretch the spring to 8.5 inches free length. Assemble the clutch with 90° (hole #3) of twist preload. This specification improves the backshifting characteristics of the machine. Restretch the spring when its free length decreases to 7.5 inches or less.

SUSPENSION

1. Install tunnel protectors (888-21978-00-001. Since the SR540E has a longer track, the standard protectors are too short. Therefore, mount the protectors as far forward as possible to protect the steel portion of the frame.

2. Countersink the suspension pivot shafts for fast installation; install the fender washers under the slide suspension mounting bolts to protect the frame.

3. Install an additional rear idler wheel on the rear axle as shown in the illustration. This additional wheel will reduce the possibility of the track derailing.

COUNTERSINK THE SUSPENSION SHAFTS

INSTALL FENDER WASHERS

SPACERS

4. Install an additional hose clamp onto each track drive sprocket. The clamps should be mounted against one another. Check the clamps before each race; they should be tight.

SUSPENSION SETTINGS

A. Smooth Course (Lake Racing)

1. Shorten the slide rail limiter straps so the suspension has the indicated amount of travel. You will have to drill a new hole in each strap.

----- --.~-----.---------.

-==-------- ---_._-------- -.- ---- -- --~-"

2

. --------------------- ~'--~

2. Install a slide suspension limiter strap to the T. S. S. steering link bolts to limit travel to 95mm (3.7 in). Set the nitrogen pressure to 7.0 kg/cm2 (100 psi).

3. Select a rear shock absorber from the Optional Parts Summary to suit the local conditions.

4. Install the 1980 SR-V front slide-rail shock (BK4-47481-oo) if desired.

5. For W. S. R. F. lake racing, install the front stabilizer kit and select a softer T. S. S. spring from the Optional Parts Summary.

SR-V Front Stabilizer Kit SRX440E Front Stabilizer Kit

B. Rough Course (Cross Country)

BL9-WOO51-00-oo BM6-W0051-oo-oo

1. Use full travel front and rear. Adjust the slide rail limiter straps for the desired steering characteristics.

2. Use the front stabilizer kit if desired.

3. Select a rear shock absorber frQm the Optional Parts Summary. We recommend the 1980 SS440/SR540 shock (BK4-47480-oo-00).

4. Install the 19BO SR-V front slide shock absorber (BK4-47489-oo-00) if desired.

TRACK STUDS AND CARBIDES

1. Break in the track and adjust it to specification before each race.

2. Stud the track with carbide penetrators where shown in the illustration. Burn the holes in the track; do not drill them .

• • • • • • • • D 0 D 0 0 0 0 D 0 D D D D D D 0 • • • •

,

• • • • D 0 D 0 D D D D D D 0 D 0 D D 0 • • • • • • • •

3

3. Install carbides on the Kalamazoo KXC 925 host bar where shown in the illustration.

a. Lake Racing (no snow)

SKI MOUNTING BOLT

3 FLATS ". '-.., I I I, l.to I' I 'f I s I .. I 7 111 I , I

approx. 45/8"

9 CARBIDES

4 FLATS I I I

approx. 5 1/3"

b. Cross Country Racing

SKI MOUNTING BOLT

4 FLATS "". 5 FLATS '-.. , , I , I I I I I I

I 1 .... 1., I'l'l s I" I ~ 7 CARBIDES

I- -l f- ----t approx. approx. 5 3/8" 6 5/8"

CHASSIS

1. Install SRX ski tip protectors (SM6-23747-00-00), radiator hose and cable ties, or other suitable ski loop padding to satisfy W.S.R.F. recommendations.

2. Disconnect the handlebar kill switch to eliminate potential mishaps.

3. Install the accessory high windshield (ABA-SK496-00-00) for comfort in cold weather racing.

4. Tie the rear snow flap to the frame to satisfy W.S.R.F. rules (see the rule book).

5. Reinforce the rear tunnel where shown in the illustration.

REINFORCE

4

6. Install a motorcycle-type brake lever with a large free-play adjusting screw to facilitate adjustment during the race. The brake light must function.

7. Drill the hyfax in the pattern shown below. Use a 3/16 inch drill, and drill the holes 4mm (0.15 in) deep.

o o 3/16" 0 0 J9 0 3/8" 00 00 O~ O~

o

o

5

SNOWMOBILE TOOL LIST

PART NUMBER DESCRIPTION

TLS-9091 0-47-01 * Sheave Align Gauge

TLS-9091 0-47-02 Sheave Align Gauge

TLS-9091 0-47-03 * * Sheave ~istance Gauge

TLS-9091 0-48-00 TSS Strut Holder

TLS-90018-59-02 YP Primary Sheave Puller

TLS-90018-81-01 ST Primary Sheave Puller

TLS-90018-80-00 Primary Sheave Holder

908-90018-83-00 Puller, Bushing

TLS-9091 0-45-00 Track Clip Tool

TLU-90901-05-20 Flywheel Puller

TLM-9091 0-60-00 Nitrogen Charging System

TLM-90910-63-00 Carry Bracket For Nitrogen Charging System

TLM-90011-53-01 Injector Needle

TLS-9091 0-60-00 Clutch Subassembly Too!

TLU-9091 0-35-00 Vacuum Press Test Kit

TLU-9091 0-22-00 COl Tester Kit

* Updated Tool Now Available * *Tool Updates TLS-90910-47-01

6

DEALER COST

$ 10.20

15.95

5.95

5.95

12.45

12.45

19.95

8.13

43.95

30.67

148.00

14.95

6.39

14.28

72.50

67.95

PERFORMANCE SUSPENSION TUNING REAR MAIN SPRING AND DAMPER ASSEMBLY

These charts are to be used as a guide. All settings must be checked under actual running conditions.

DAMPER DAMPER SPRING SPRING SPRING TENSION COMPRESSION FIRST

PART NUMBER PRELOAD RATE RATE RATE USAGE

8K4-47480-00-00 33.1 kg 1.10 T 65 C55 SR540D,SS440D

8K2-47480-00-00 23.8 kg 1.58 T 95 C 85 SRX440D

8L8-47480-00-00 12.0 kg 1.2 - 1.6 T65 C55 SRX440E, SS444E,SR540E

NOTE: The lowest preload and damper compression rate allows the most weight transfer and best acceleration.

REAR MAIN SPRING PRELOAD ADJUSTMENT

LOWEST PRELOAD <IIIIC ... -------------... _~ HIGHEST PRELOAD

STD. SEnlNG

NOTE: The lowest preload allows the most weight transfer and best acceleration.

The highest preload is most resistant to bottoming.

7

SPRING PART NUMBER

90508-99479-00 90508-99480-00

90508-95476-00 905O8-954n-OO

90508-85471-00 90508-85472-00

90508-99482-00 90508-99483-00

90508-90409-00 90508-90408-00

90508-80410-00 90508-80411-00

PERFORMANCE SUSPENSION TUNING REAR SUSPENSION HAIR PIN SPRING

SPRING SPRING SPRING PRELOAD RATE COLOR

12.8 kg 435.8 Yellow kg mm/deg.

15.9 kg 358.1 Pink kg mm/deg.

8.5 kg 232.7 Brown kg mm/deg;

10;0 kg 437.5 Red-Green kg mm/deg.

NA 302.9 Orange kg mm/deg.

NA 191.2 Blue kg mm/deg.

NA = Information Not Available

8

FIRST USAGE

SS440D Retrofit Spring

SR540D Retrofit Spring

SS440E Standard

SR540E SRX440E

Standard

SRX440D SR540D

SS440D

PERFORMANCE SUSPENSION TUNING

The fewer number of wheels that can be used without Hyfax wear, the greater the acceleration and top speed.

CONDITION #2 CONDITION #3 ACCESSORY WHEEL CONDITION #1 HARD PACKED ICE OR

PLACEMENT SOFT SNOW OR LlnLE SNOW NO SNOW

~i~O No Hyfax Wear less Hyfax Wear less Hyfax Wear less More More

Performance Performance Performance

23_ ) ~ ) ~ ) ~

"- ~ m---=:..

" .0 , ~ , f , ,

"- - No Hyfax Wear More Hyfax Wear More Hyfax Wear More less less

Performance Performance Performance

NOTE: Wheels #1 and #3 come in the crate.

9

SPRING PART NUMBER

90501-75612-00

BlO-00000-10-00

BlO-OOOOO-OO-OO

90501-70584-00

-C; ~ -III () ~

2 z o iii fn III ~ A.

~ ()

PERFORMANCE SUSPENSION TUNING TSS SPRINGS

200

175

STRUT TRAVEL (MM)

COLOR FEELING RATE

Red Hard 1.6

Blue Medium 1.0 -1.6

White Medium Soft 1.01.4

No Color Soft 0.8 -1.2

TSS PRELOAD

, ORIGINAL

i APPLICATION

SRX440E at SR540E

Accessory

Accessory

SR540D

NOTE: TSS preload is set by adjusting the nitrogen pressure In the shock absorber.

TSS NITROGEN PRESSURE

Max. 284lbs.

Std. 2131bs.

Min. 185lbs.

10

PERFORMANCE SUSPENSION TUNING

FRONT STOPPER BAND #1

C A #5~----~.-----~~----~------~-------e~----~

CII #4 z C .. I11:III III A. A. #3 e In I11:III C III D .. #2

B #1 ~----~.-------+-------+--------

The Indicated settings provide: A. Best straight line acceleration and top speed; B. Most positive steering; C. Lowest center of gravity; D. Maximum suspension travel. * Stopper band standard position. X Un useable combination; shock will top out.

11

SPRING PART NUMBER RATE

9050.1-45534-0.0. 1.0.0.

9050.1-50.50.0.-0.0. 1.40.

90501-50.543-0.0. 1.40.

9050.1-50.351-0.0. 1.40.

9050.1-55230.-0.0. 1.50.

9050.1-50.622-0.0. 1.50.

9050.1-50447-0.0. 1.75

9050.1-55343-0.0. 1.75

90.50.1-55241-0.0. 1.75

9050.1-55403-0.0. 1.75

9050.1-55225-0.0. 1.75

90.501-55404-0.0. 1.75

90.50.1-55419-0.0. 1.80.

9050.1-5540.4-0.0. 1.80.

9050.1-55456-0.0. 2.0.0.

PRIMARY SPRINGS (Listed In Order of Spring Rates)

WIRE OUTSIDE NUMBER PRELOAD COLOR DIA. DIA. TURNS

25 Blu-Grn 4.5 55 4.68

25 Red 5.0. 55 5.0.7

20. Grn-Grn 5.0. 55 5.57

40. Yel-Grn 5.0. 54 5.30.

65 Red-SII 5.5 54.5 6.50.

30. Yel-Pnk 5.0. 55 4.83

30. Pnk-Wht 5.0. 55 4.40.

30. Red-Blu 5.5 55 5.80.

35 Red-Pnk 5.5 55 5.80.

40. Yel-Wht 5.5 54.5 5.75

45 Red-Grn 5.5 55 5.80.

55 Grn-Pnk 5.5 55 5.80.

42 Brn-Wht 5.5 55 5.50

49 Org-Wht 5.5 55 5.50.

30. SiI-Wht 5.5 55 5.50.

FREE FIRST LENGTH USEAGE

86.5 EX44o.D

79.4 ET34o.D

75.8 EC54o.

90.1 GPX-G 50.0.0. rpm N

10.4.8 GPX433F GYT Kit

81.5 SR54o.E

78.6 EX44o.A

78.6 SRX Opt. 40.0.0. rpm

81.5 GPX338/433F Std.

84.4 EX44o.

87.2 Tuning Part

92.9 Tuning Part

84.8 SRX34o. 50.0.0. rpm

88.2 SRX44o. 50.0.0. rpm

77.3 SRX44o.A Std. -_ .. --

(Continued)

SPRING PART NUMBER RATE PRELOAD

90501-55487-00 2.00 50

90501-55242-00 2.00 60

90501-55356-00 2.00 64

w 90501-50396-00 2.00 20

90501-55345-00 2.05 20

90501-55397-00 2.22 24.5

90501-55388-00 2.40 40

90501-55485-00 2.50 30

90501-55559-00 3.00 20

(Continued)

PRIMARY SPRINGS (Listed In Order of Spring Rates)

WIRE OUTSIDE NUMBER COLOR DIA. DIA. TURNS

Red-Org 5.5 54.5 5.0

Red-Org 5.5 55 5.40

Blu-Sil 5.5 55 5.40

Grn-Wht 5.0 55 4.10

Red-Red 5.5 54.5 5.30

Red-Wht 5.5 55 4.50

Blu-Wht 5.5 54.5 4.90

Brn-Wht 5.5 55 4.50

Blu 5.5 55 4.60

FREE FIRST LENGTH USEAGE

93.0 SRX440A Modified

91.5 GPX338F GYT Kit

93.5 GPXG GYT Kit

71.5 SRX340 Std.

71.3 GPXG Std.

72.5 SRX440 Std.

78.2 EX340

73.5 SRX440A Improved

68.2 ET250D

SECONDARY SPRING CHART

SPRING CONSTANT NO. COIL WIRE FREE

PART NUMBER kg/mm TURNS' DIA. DIA. LENGTH COLOR USED ON

90508-45301-00 4.86 8.0 64.5 4.5 120 Silver EX440 90508-45287-00 4.32 9.05 64.5 4.5 120 Blue EX340, A, B 90508-45286-00 4.86 8.05 64.5 4.5 85 Yellow SRX340,SRX440, A, B,C,

0, E, SR540D, E, EX440, A, B, C, 0, E, SS440D, E, EXCEL-V, EC540D

90508-40341-00 4.86 5.05 64.5 4.0 85 White SRX440, A 90508-40080-00 3.19 9.9 50.0 4.0 105 None ET250A, B, C, 0, E '<t

ET340B, C, 0, ET340EC ET30OC, 0, E

SPRING PULL CHART

Hole Number 2 3 4 1 2 3 Degrees 600 900 1200 1500 1800 2100

Preload (TWist) 1/2 3/4 1 1-1/4 1-1/2 1-3/4 Silver - Lbs. Pull 8 11 14 16 19 22 Blue - Lbs. Pull 6 9 11 13 16 19 Yellow - Lbs. Pull 7 10 12 15 18 White - Lbs. Pull 6 9 11 14 17

All ET Series 10 Lbs. Pull@1600 Preload (Twist)

Refer to service data for additional information on proper settings

CONTENTS

I NEW SERVICE PROCEDURE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 1. V-BELT CLUTCH ......................................... 1 2. FRONT AXLE ........................................... 15 3. FUEL TANK ............................................ 16 4. BELLY PAN LID ......................................... 17 5. PULSER AND CHARGING COIL TEST ....................... 18 6. LIGHTING COIL TEST .................................... 18

II SPECiFiCATIONS ........................................... 19

I. NEW SERVICE PROCEDURE

1. V-BELT CLUTCH NOTE: ________________________ _

The following items under "4-1. Drive" in the SR540E Service Manual will be changed as described below:

A. Sheave adjustment B. Primary sheave C. V-belt D. Secondary sheave

A. SHEAVE ALIGNMENT

1. Sheave distance 2. Sheave off-set

270 ~ g mm 11 ± 0.5 mm (0.43 ± 0.02 in)

(10.6 ~g.11 in)

1. Using the sheave gauge, check the sheave offset. If the gauge does not contact the primary and secondary sheaves at the four indicated points, the sheave offset is incorrect.

-1-

Sheave gauge: YS-91047 (U.S.A.) 90890-01702

2. Check the sheave center-to-center distance.

3. If the center-to-center distance or offset is not within the specification, adjust it in the following manner:

4. Loosen the four engine-mounting bolts. By moving the engine back and forth, adjust the sheave distance so that the center-to-center distance between the primary sheave mounting bolt and secondary sheave mounting bolt is equal to the sheave gauge setting spefied above.

5. Adjust the thickness of shims on both ends of the secondary sheave so that the distance (offset) between the primary fixed sheave and secondary sliding sheave is equal to the sheave gauge.

6. Repeat steps 4 and 5 above until the sheave distance and sheave offset are adjusted correctly.

NOTE: ______________________ __

Select proper shims to be used at A and B. The total clearance at A and B should be 1.0 mm (0.04 in) or less.

90201-225A4 ~~~~~~~~~~~~~~~ 90201-222FO

7. Tighten the engine mounting nuts while taking care not to move the engine.

B. CLUTCH TUNING

The clutch may require tuning depending upon the area of operation and the desired handling characteristics. The clutch can be turned by changing engagement & shifting rpm. Clutch engagement rpm is defined as the engine speed where the machine first begins to move from a complete stop. Shifting rpm is the engine speed when the

Engine rpm

t

90201-252F 1

Tightening torque: 52 Nm (5.2 m· kg, 37.6 ft·lb)

machine passes a point 200 - 300 m (650 -1000 ft) from the starting position after the

machine has been started at full-throttle from a dead stop. Normally, when a machine reaches shift rpm, the vehicle speed Increases but the engine speed remains nearly constant. Under unfavorable conditions, however (wet snow, icy snow, hills, or rough terrain), engine speed can decrease after the engine has reached shifting rpm.

Engine rpm

t Clutch shifint rpm

Clutch shifting rpm

Clutch engagement rpm


- Travelled distance

Starting position 200 - 300 mm (650 -1000 ft)

Good Condition

-2-

Travelled distance r-------------,r- -Starting position 200 - 300 mm (650 -1000 ft)

Bad Condition

1. Clutch setting data

a. Standard specification

S.t.d. SPEC High altitude spec

Engagement r.p.m. 3600± 200 +-

Shifting r.p.m. 7000 ± 200 +-

Parts No. 90501-55672 90501-50500

Set weight 36 kg 25 kg Primary spring .

Spring constant 2.1 kg/mm 1.4 kg/mm

Color GREEN - ORANGE RED

Q'ty 2 p.c.s. +-Spider shim

Part No. 90201-327E3 (3.2 t) +-90201-32710 (1.6 t)

Primary spring shim Q'ty 0 +-

Mark 8R6 8R9 Weight .

Part No. 8R6-17633-00 8 R9-17633-00

Q'ty .

2 p.c.s. 1 pc (No.1 Hole) Weight rivet

Parts No. 90261-06015 90261 -06016

Parts No. 90508-45508 +-

Twist angle 90° +-Secondary spring

Spring hole No. No.3 t +-

Color GREEN +-

NOTE: __________________________________________________________ __

The "Highland spec" applies to operation at an altitude of more than 1 ,500 meters (4,500 feet).

b. How to change clutch engagement rpms and clutch shifting rpms

~ Clutch engagement r.p.m. Clutch shifting r.p.m.

Decreasing Increasing Decreasing Increasing

Primary spring shim Lessen number Increase number

of shims of shims - -

Spring - - Decrease Increase constant

Primary spring Preload Decrease Increase - -

Centrifugal force of weight Increase Decrease Increase Decrease

Torsion spring - - Decrease Increase constant

Secondary spring Twist angle - - Smaller wind Greater wind

-3-

2. Primary clutch engagement rpm setting

The factors which change the clutch engagement rpm are the primary spring shim, primary spring preload, and centrifugal force of the weights as shown in 1-b. Therefore, the clutch engagement rpm can be adjusted by replacing the primary spring shim, the primary spring itself or the primary weight rivets.

Standard clutch engagement rpm: 3400 ~ 3800

Clutch engagement rpm for highland: 3400 ~ 3800

a. Primary weight setting By changing the position and quantity of primary weight rivets, the thrust of the weights is changed, and thus the engine rpm at which the clutch is shifted is also changed. (As a result, the engine rpm at which the clutch is engaged is changed.)

NOTE: ________________________ __

The position of rivets for the three weights must be the same.

1) Removal of rivets Drive out in the manner as illustrated.

2) Clinching of rivets After driving in the rivets, file down the rivet heads so they are flush with weight surfaces.

3. Secondary clutch shifting rpm setting The secondary clutch must be turned to match snow and weather conditions. Tuning the clutch keeps the engine operating in the proper rpm range.

-4-

Standard clutch shifting rpm: 6800 ~ 7200

Clutch shifting rpm for highland: 6800 ~ 7200

a. Secondary spring setting

1) Secondary spring position The spring seat is provided with four holes, Nos. 1 to 4, so that the secondary spring position can be changed as required.

1. Spring seat

2) Secondary spring tension The secondary spring tension can be changed by moving the spring position from the free position in order to reset the clutch shifting rpm as required. The four holes are spaced at intervals of 30° .

Secondary spring Spring wind position

No.1 30°,150°,270°

No.2 60°,180°

No.3 90°,210°

No.4 0°,120°,240°

Winding the spring more (i.e., from 30°

to 60°) will increase the clutch shifting

rpm and vise versa. Snow conditions will

also require a change of the spring

tension in order to attain the standard

shifting rpm. The spring tension must be

greater on wet snow than on packed

snow. Less tension is needed on icy snow.

3) Secondary spring setting The secondary spring settings are

classified into two types as shown below.

Select a proper setting according to

operating conditions. (For the setting

procedure, refer to "E. Secondary

Sheave.")

Course Trail and tour

Setting factor Position of spring seat

Ice snow No.2

Packed snow Std.

Wet snow Std.

C. V-BELT

1. Removal a. Turn the secondary sliding sheave clock

wise and push it towards the chain case. b. While holding the sliding sheave in this

compressed position, remove the V-belt from the secondary sheave, then from the primary.

2. Inspection a. Visually inspect the V-belt for signs of

damage. Replace the belt if it is damaged.

b. Measure the width of the V-belt. If the belt is worn beyond the wear limit, replace it.

Wear limit: 26 mm (1.02 in)

\ \ \ \ \ \ \ \ \ \ \

I I I I I I I I I

1. New: 31.5 mm (1.24 in) 2. Wear limit: 26 mm (1.02 in)

Twist

60°

Std.

Std.

-5-

Std. secondary spring:

PIN: 90508-45508

Color code: Green

Std. secondary spring position: No.3

Std. secondary spring twist: 90°

Lake surface

Position of spring seat Twist

No.2 60°

Std. Std.

Std. Std.

c. Measure the length of the V-belt. It should be within specification, if not, replace the belt.

Part No. Length of V -Belt

SF2-17641-00 1,099 mm (42.S in)

Q)

1. V-belt length

0_ PRIMARY SHEAVE

Washer

Tightening torque: 362 tt-Ib) 500 Nm (50 m-kg,

• NOTE: X

Oiling Point

No oiling or greasing is allowed.

Apply Three Bon . d No 1305 to the top four threads.

Steel shim Weight

Roller pin

Spider

Slider

Tightening torque: e First tighten the bolt to a torqu f A then loosen it.

~eti~hten bolt to a final torque of

!.: 120 Nm (12 m-kg, 87 ft-Ib)

B: 58 Nm (5.8 m-kg, 47 tt-Ib)

-6-

Plastic washer

Sliding sheave

CAUTION: Always use a self-locking bolt. Self-locking bolts must never be reused.

Tightening torque: 54 ftolb) 7.5 Nm (0.75 m-kg, .

Sheave cap

Sheave cap bolt

Tightening torque: 11 ft-Ib) 15 Nm (1.5 m-kg,

1. Removal a. Remove the drive guard, and remove the

V-belt. b. Hold the fixed sheave with the primary

sheave holder and remove the clutch bolt. Drive the primary sheave off the crankshaft with the primary sheave puller.

Primary sheave holder: YS-01880 (U.S.A.) 90890-01701

Primary sheave puller: YS-01882 (U.S.A.) 90890-01890

1. Sheave holder 2. Sheave puller

2. Disassembly a. Loosen the six sheave cap bolts b. Remove the three sliders. c. Loosen the six weight pin securing bolts

and remove the weights. d. Loosen the six collar pin securing bolts

and remove the collars. e. Disassembling the spider, sliding sheave,

and bushing (large)

NOTE: ______________________ _ For this operation, the special tools and

. Three Bond No. 1305 (required for spider and fixed sheave assembly) are necessary. If these are unavailable, avoid disassembling.

1) Secure the primary sheave assembly to the tool (1) gripped in a vise, using the primary sheave bolt.

Yamaha spider wrench: 90890-01711 YS-28890 (U.S.A.)

-7-

Tightening torque: 120 Nm (12 m·kg, 87 ft·lb)

. , 1. Yamaha spider wrench YS-28890 90890-01711 NOTE: ______________________ __ Thoroughly clean the tapered portions of the primary sheave and tool (1).

2) Install the tool (2) onto the spider and loosen the spider.

Loosening torque: 500 '" 1 ,000 N m (50'" 1 00 m· kg, 360'" 730 ft·lb)

WARNING:

To loosen the spider, high torque is required and therefore, make sure the primary sheave, vise, and tools are tightely secured also take care not to crack the spider.

3) Remove the primary sheave bolt, and using the primary sheave puller, remove the primary sheave assembly from the tool (1).

Primary sheave puller: 90890~01898 YS-01882 (U.S.A.)

3. Inspection a. Inspect the tapered ends of the crank

shaft and the primary fixed sheave for scraches. If either is severely scratched, replace it. If scratches are minor, burnish the component with emery cloth.

b. Check the primary sheave cap bushing and the sliding sheave bushing for wear. If worn beyond tolerance, replace the bushing. Use the bushing tool if a bushing is difficult to remove.

Bushing tool: 90890-01713

1. Bushing tool

-8-

~ Bushing clearance, limit

Small bushing Large bushing

Inside 0.25 mm (0.01 in) 0.25 mm (0.01 in)

Outside 0.25 mm (0.01 in) 0.25 mm (0.01 in)

c. Weights Check the bushing bore inside diameter of each weight and its contact surface with the collar. If worn more than limits, replace them with new ones.

Bushing bore Contact surface with collar

Wear diameter (d) A B

limit 10.20 mm 0.5mm 1.0mm (0.40 in) (0.021 in) (0.04 in)

Contact surface with collar B

d. Roller Check the inside diameter of the roller bushing, then check the contact surface of the roller and the weight. If either surface is worn unevenly or more than acceptable limits, replace them.

Bushing bore Contact surface Wear diameter (d) with weight (D) limit

10.3 mm (0.41 in) 15.0 mm (0.59 in)

Contact surface with weight

d

Uneven wear

If the outer surface of the roller is worn unevenly, the roller is probably seized to the pin. Be sure to check the roller pin.

e. Weight pins and roller pins Check both weight and roller pins. If metal dust collects on pins, remove it using sandpaper (# 800 - # 1000). If the chrome-plated surface of the pin scales off, replace the pin with a new one.

f. Slider Install the slider onto the sliding sheave, and check for wear on its contact surface with the spider. If worn more than limits, replace the slider. Also if it is cracked, it should be replaced.


-9-

1. Wear limit

g. Spider Check the contact surface of the spider with the slider. If it is worn more than limits or cracked, replace it with a new one.


1. Wear limit

h. Primary spring Check the primary spring for damage or fatique, and replace it as required.

4. Assembly a. Install the large bushing into the sliding

sheave. Using the weight pin, install the weight, washers, and steel shim in the sliding sheave.

Weight

Plastic washer

Sliding sheave

NOTE: ____________ _

The weight should be adjusted so that it has no thrust play. If any Fe-washer is added, it should be installed in the position indicated by the arrow mark.

No. of standard steel shim: 1 pc. I·

Weight pin tightening torqu.e: 75 Nm (0.75 m· kg, 5.4 ft·lb)

b. Using the roller pin, install the collar and washer on the slider.

Roller pin tightening torque: 7.5 Nm (0.75 m· kg, 5.4 ft·lb)

c. Install the spider, sliding sheave and fixed sheave

1) Install the sliding sheave, spider shim and washer onto the fixed sheave.

2) Apply Three Bond No. 1305 to the threaded portion of the fixed sheave.

Apply to the top four threads

-10-

Apply Three Bond No. 1305 to:

4 threads

1. Three Bond should be applied only to the area apecified. Never apply to the outer surface of the bushing (large) or other areas.

2. Do not use the clutch until the Three Bond has completely cured. Wait 24 hours before using the clutch.

3) Align the arrow mark on the spider with the slot in the sliding sheave edge, and install the spider onto the fixed sheave.

Slot in sliding sheave,

4) While sliding the slider toward the spider, install the slider onto the sliding sheave.

5) According to "e-l) and 2)," install the tool (2) on the spider and tighten.

Tightening torque:

500 Nm (50 m' kg, 360 ft·lb)

1. Yamaha spider wrench YS-28890 90890-01711

WARNING:

Since tightening torque is high, make sure the primary sheave, vise, and tools are tightely secured. Also take care not to crack the spider.

6) Remove the primary sheave according to "2 Disassembly e-3".

d. Install the primary spring, and align the arrow mark on the sheave cap with the slot in the sliding sheave (and also with the arrow mark on the spider), and install the sheave cap.

1. Sliding sheave slot 2. Spider arrow mark 3. Sheave cap arrow mark

- 11 -

e. Tighten the sheave cap bolts.

Tightening torque: 15 Nm (1.5 m'kg, 11 ft·lb)

5. Installing Hold the primary fixed sheave with the primary sheave holder, and torque the sheave bolt to specification.


Tightening torque:

Tighten the bolt to A to properly seat the primary sheave on the crankshaft. Loosen the bolt, then torque it to B, the final torque.

A: 120 Nm (12 m'kg, 87 ft·lb) B: 58 Nm (5.8 m' kg, 42 ft·lb)

E. Secondary sheave

Tightening torque: 4 ~ 7 Nm (0.4 ~0.7 m·kg. 2.9 ~ 5 ft'lb)

CAUTION:------------, Turn the screw securing the collar clockwise when viewed from the collar side. and lock the secondary shaft and collar. tighten the secondary sheave.

Check the ramp shoes on secondary sliding sheave for wear. Replace ramp shoes as required.

Sliding sheave

Fixed sheave

Tightening torque: 50 ~ 70 Nm (5.0 ~ 7.0 m·kg. 36.2 ~ 50.6 ft'lb)

Greasing point ... -+ NOTE: X -+

No oiling or greasing is allowed

1. Removal a. Apply the brake and remove the secon

dary sheave mounting bolt. b. Remove the secondary sheave from the

jack shaft.

2. Disassembly

WARNING:

Use extreme CAUTION when disassembling the secondary sheave. Serious injury can occur from the sudden release of spring tension. Use the Yamaha Secondary Sheave Assemoly Tool to contain the spring tension before removing the retaining circlip. DO NOT attempt this procedure unless you have the proper tools and understand the instructions thoroughly.

-12-

a. Install the secondary sheave onto the tools (1) and (2) so that the fixed sheave faces downward.

Secondary Compressor: 90890-01712 YS-28891 (U.S.A.)

b. Hold the spring seat with the tool (3), screw in the tool (4), and separate the spring seat from the plain washer by pushing the spring seat downward.

c. Remove the circlip, and while screwing out the tool (4), set the secondary spring free.

d. Remove the spring seat, secondary spring, sliding sheave and fixed sheave.

3. Inspection a. Inspect both sheaves. If either is warped,

replace it. b. Inspect the ramp shoes on the sliding

sheave; replace as necessary. c. Check the sheave bushings for wear; re

place the sheave as required. d. Check the spring. If it is fatigued or

damaged, replace it.

4. Assembly a. Install the secondary fixed sheave and

sliding sheave onto the tools (1) and (2). b. Hook the end of the secondary spring

onto the spring hole in the sliding sheave.

c. Hook the other end of the secondary spring onto the hole (indicated by No.) in the spring seat.

Std. spring position: No.3 hole

-13 -

d. Install the plain washer and circlip. e. Install the tools (3) and (4), and screw in

the tool (4) to the position at which the splined portion of the spring seat nearly aligns with the splined portion of the fixed sheave.

f. Bring the spring seat splines to align with the fixed sheave splines by hand.

NOTE: ________________________ __

Make sure that the three cams of the spring seat are in a position where they can move into the guide hole in the sliding sheave cam.

g. Screw in the tool (4) so that the spring seat is splined to the sliding sheave.

h. Screw in the tool (4) to bring down the spring seat to a position where the spring seat cam does not contact the sliding sheave cam when they turn.

~----------Spring seat cam

Clearnace

~-----Sliding sheave cam

-14-

i. Turn the sliding sheave the specified degrees in the c?unterclockwise direction, and screw in the tool (4) so that the spring seat engages with the sliding sheave.

Standard twist angle: 90°

1. Sliding sheave

j. Screw in the tool (4), and while pushing the spring seat, fit the circlip to the fixed sheave to lock the spring seat.

. Circlip k. Remove the secondary sheave from the

tool.

2. FRONT AXLE

The A and B items under "4-1-F-3. Installation" in the SR540E are altered as follows:

L/H GUIDE WHEEL

99mm (3.90 in)

104 mm (4.09 in)

A. Installation 1) Press-fit the sprocket wheels (8R6-

W4753-00) onto the front axle ..

50mm (.1.97 in)

189.5 mm (7.46 in)

NOTE: ________________________ _ The right and left sprocket wheels shoud be installed so that the arrow marks on the A surfaces are aligned.

2) Secure both guide wheels to the front axle with the collar set bolts.

Tightening torque: 5.5 Nm (0.55 m· kg, 4 ft·lb)

104 mm (4.09 in)

NOTE: ________________________________________________________ __

The left side guide wheel should be set to the position shown in the figure after installing the front axle onto the chassis.

-15-

3. FUEL TANK

The "5-6. Fuel tank" in the SR540E is changed as follows:

1. Check all lines. If any are cracked, crimped or damaged in any way, replace them.

2. Be sure all lines are secured in place by a retaining clip.

-16 -

....... __ ._ .. _. pipe

uel filter

3. Be sure that all lines are routed correctIy. The breather pipe must be routed so that no fuel will leak during operation.

4. Replace the fuel filter each season.

,

4. BELLY PAN LID

Two belly pan lids are attached to the front part of the belly pan. These lids should be used in the following manner.

Holed lid

Belly pan

2. When it is not so cold When it is not so cold in early spring, the blind lid should be removed and the

Holed lid

-17-

1. Standard type As shown below, the holed lid is attached to the engine room side, and the blind lid is attached to the outside of the belly pan.

Engine room side

Outside

holed lid should be installed as shown below for better cooling of the engine and clutch.

Engine room side

Outside

5. PULSER AND CHARGING COl L TEST

The "6-1-G" in the SR540E is changed as fol!ows.

Check the resistance of each coil as shown in the illustration. If the resistance is not within specification, the coil is not working. Check the connections. If the connections are good, the coil is damaged internally; it should be replaced.

Pulser coil ----Charge coil--

590Q (Pulser coil!

Pocket tester: YU-03112

Charging coil resistance: Black to Brown leads:

590 Q ± 10% at 20°C (68° F)

Pulser coil resistance: Black to White/Red leads:

15.1 Q ± 10% at 20°C (68°F)

® 15.1 Q (Charge coil!

.QXl

r- "'--'----,..,... I I I

L--::==-_*-CDCJ i ® : ~--+®C>_- __ 1 I ®~ _________ J

6. LIGHTING COl L TEST The "6-2-C" in the SR540E is changed as follows.

Check the resistance between the yellow lead and ground. If the resistance is not within specification, the coil is not working. Check

1. Yellow 2. Brown 3. Black 4. White/Red 5. Flywheel magneto 6. Pocket tester 7. Set tester at "R x 1" position

the connections. If the connections are good, the coil is broken internally; it should be replaced.

Lighting coil resistance: Black & Yellow:

0.19 Q ± 1 0% at 20° C (68° F)

===T---®

0.,90"0% ~ Q x 1

o ~/'<Jr-_

1. Yellow 2. Brown 3. Black 4. White/Red 5. Flywheel magneto 6. Pocket tester 7. Set tester at "R x 1" position

-18 -

,

SPECIFICATIONS A. General * New specification (Compared with 1981 SR540E)

Model SR540F

Model: Model (I.B.M. No.) *SR540F (8R6) Frame I.D. & starting number *8R6·027101 Engine I.D. & starting number * SA535·0271 0 1

Dimension: Overall length 2,610 mm (102.7 in) Overall width (std) 1,080 mm (42.5 in) Overall height (W/windshield) 970 mm (38.2 in)

B. Engine


induction, twin cylinders Engine model SA535 Displacement 535 cc (32.65 cu.in) Bore x Stroke 73 x 64 mm (2.874 x 2.52 in) Effective compression ratio 6.0: 1 Starting system Recoil hand starter Ignition system C.D.I. Lubrication system "Autolube" oil injection

Cylinder head: Combustion chamber volume (with spark plug) 27.5 cc (1.68 cu.in) Compression chamber type Dome + Squich Head gasket thickness x q'ty 0.5 mm (0.02 in) x 1 pc.

Cylinder: Material Cast iron sleeves aluminum Bore size 73 mm (2.874 in) Taper limit 0.05 mm (0.0020 in) Out of round limit 0.01 mm (0.0004 in)

Piston: Piston skirt clearance (measuring point) 0.055 - 0.060 mm (0.0022 - 0.0024 in)

[17 mm (0.67 in) from piston skirt end) Piston oversize 1st 73.25 mm (2.884 in)

2nd 73.50 mm (2.894 in) 3rd 73.75 mm (2.904 in) 4th 74.00 mm (2.913 in)

Piston pin outside diameter x length cf> 20 x 56 mm (cf> 0.787 x 2.20 in)

Piston ring: Piston ring design Keystone Ring end gap (installed) *0.2 - 0.4 mm (0.008 - 0.Q16 in)

Small end bearing: Type Needle bearing

Big end bearing: Type Needle bearing


Crankshaft assembly width (F) 6 +0 (6 +0 o -0.05 mm 2.3 2 _ 0.002 in)

Crankshaft deflection (D) D·1: 0.03 mm (0.0012 in) D·2: 0.04 mm (0.0016 in) D·3: 0.04 mm (0.0016 in) D·4: 0.05 mm (0.0020 in)

-19 -

Connecting rod big end side clearance (C) 0.25 - 0.75 mm (0.010- 0.030 in) Connecting rod small end deflection (P) 2.0 mm (0.079 in)

I -jf- P

Q

I J

LI~A~~ Crank pin outside diameter x length et> 24 x 59 mm (et> 0.945 x 2.323 in) Crank pin type Solid shaft assembly type with serration Crank bearing type (Left) x q'ty #6306 special x 2 pcs. Crank bearing type (Center) x q'ty #6206 special x 2 pcs. Crank bearing type (Right) x q'ty #6206 special x 1 pc. Crank oil seal type (Left) x q'ty FWJ-3278 9.5 TS x 1 pc. Crank oil seal type (Center) x q'ty Labyrinth seal x 1 pc. Crank oil seal type (Right) x q'ty FWJ-3248 10-1 TS x 1 pc.

Cooling fan: Fan belt tension 4 - 6 kg/8 mm (8.8 - 13.2Ib/0.31 in)

Carburetor: Type & manufacturer/quantity B D44-38/K E I H I N/1 pc. I.D. Mark *8R600 Main jet (M.J.) *#155 Main air jet (M.A.J.) #180 Power jet (Pw.J.) #150 Power air jet (Pw.A.J.) #170 Slow jet (S.J.) #92 Slow air jet (S.A.J.) #100 Pilot screw (P.S.) *2.0 turns out Starter jet (St.J.) #160 Float height 15+ 2 mm (O.59+ 0.08 in) -3 -0.12 Idling engine speed 1500 r/min

* Main jet setting chart

1""- Temperature _30oe -20oe -10oe oOe 100e 200e Altitude

"" ' (- 22°F) (_4°F) (14°F) (32°F) (50°F) (SSoF)

.. #150 .. Sea level

r----#155 #145 .. .. .. #145 --600 m (2000 ttl 1--#150 #140 .. -.. #140 ..

-1200 m (4000 ttl r----#145 #135 .. .. .. #135 --1800 m (6000 tt) 1----#140 #130 .. .. .. #130 ..

-2400 m (8000 tt) -#135 #125 - -.. #125 ..

- 3000 m (10000 tt) -#130 #120 - ..

-20-

Intake reed valve: Type Bending limit Stopper height

Lubrication: Autolube pump - Color code Autolube pump - Minimum stroke Autolube pump - Maximum stroke Autolube pump - Reduction ratio Autolube pump - Output Min./200 strokes Autolube pump - Output Max./200 strokes Autolube pump wire free play Oil tank capacity Oil grade


Transmission: Type Drive ratio Engagement rpm Shfiting rpm Primary spring:

Part No. Color code

Secondary spring: Part No. Color code

Secondary spring pre·load (twist)

Sheave distance

Sheave off·set V-belt width and outer line length V·belt wear limit

Track suspension: Type Damper type Spring color code (Front) Spring color code (Rear) Slide runner wear limit Track width Track deflection Length on ground Wheel sprocket material and number of teeth Stopper band length (Front) Stopper band length (Rear)

Secondary drive: Type Reduction ratio Chain pitch x Number of links

Free play


Brake: Type Brake pad thickness Brake pad wear limit Brake cable "L" distance Clearance between lining pad and disc

V type 0.6 mm (0.024 in)

* 12 ± 9.2 mm (0.4724± 0.0079 in)

*Gray

0.20 - 0.25 mm (0.0079 - 0.0098 in) 1.65 - 1.87 mm (0.0650 - 0.0736 in)

* 1/36 0.95 - 1.19 cc (0.0321 - 0.0402 oz) 7.84 - 8.89 cc (0.2651 - 0.3006 oz) 25 ± 1 mm (0.98 ± 0.04 in) at idle 2.5 Liter (2.6 US. qt) YAMALUBE 2-cycle

V-belt automatic centrifugal engagement 3.5: 1 - 1 : 1 3400 - 3800 rpm

* 6800 - 7200 rpm

*90501-55672 * Green - Orange

*90508-45508 * Green *900 (No.3 holes)

270~g mm (10.63~g.11 in)

11 ± 0.5 mm (0.433 ± 0.020 in) 31.6 x 1,099 mm (1.24 x 43.3 in) 26 mm (1.02 in)

Slide rail suspension Oil and gas damper Red - Green No painted 10 mm (0.394 in) 381 mm (15 in) 25 - 30 mm/l0 kg (0.98 -1.18 in/22Ib) 942 mm (37.1 in) Double polyethylene 9 teeth

*243 mm (9.57 in) (No.1 hole from the bottom) * 168 mm (6.61 in) (No.3 hole from the bottom)

Chain (#35K-3) 17/31 (1 : 1.824) 9.525 mm (0.375 in) x 66L

10 + 5 (04+ 0.2 . ) _2 mm . -o.oa m

250 cc (8.5 oz) Gear oil API "GL-3" (SAE #75 or 80)

Floating disc type 5 mm (0.20 in) 1.0 mm (0.04 in) 57 mm (2.24 in) 0.15 - 0.3 mm (0.006 - 0.012 in)

- 21-

D. Chassis

Frame: Material

Steering system: Caster (ski column)

Chamber Ski length x width x thickness Ski stance Ski toe-out Steering linkage type Lock to lock angle (Ski)

Steering angle

Front suspension: Type (YAMAHA T.S. SUSPENSION) Damper type

Fuel tank: Capacity Fuel grade

E. Electrical

Ignition system: Type - flywheel magneto (C.D.I. Type)

Model/Manufacturer Voltage Charging coil resistance Pulser coil resistance

Ignition timing: B.T.D.C.

Ignition coil: Manufacturer/Model/Quantity Spark gap

Primary winding resistance

Secondary winding resistance

Diode (Yes or No)

Spark plug: Type & quality Spark pi ug gap

Spark plug cap: Type Noise suppressor resistance

C.D.I. unit: Model/Manufactu rer

Lighting system: Lighting output Lighting coil resistance Headlight type

Bulb wattage/q'ty Tail/Brake light wattage

Aluminum + Steel

25° 0° 980 x 120 x 2 mm (38.6 x 4.7 x O.OS in) 880 mm (34.6 in) o mm (0 in) Tie-rod Right ski Left ski Right: 46° Left: 46°

Coil spring

L: 27.9° L: 33.4°

Oil and gas damper

R: 33.4° R: 27.9°

26.6 L (5.9 Imp gal, 7.0 US gal) Regular gasoline

F3T352/mitsubishi 12V

*590 Q ± 10% at 20°C (68°F) (Brown-Black) *15.1 Q± 10%at20°C (68°F) (White/Red-Black)

1.5 mm (0.059 in)

HITACHI i TOYO-DENSO

*CM62·21/1 pc. : YW-51/1 pc. I

9 mm (0.4 in)/300 rpm I +-I

11 mm (0.6 in)/3,OOO rpm :+-0.15 Q ± 10% at : 0.12 Q ± 10% at

20°C (6SoF) I 20°C (68°F) I

*3.6 kQ ± 10% at : 4.0 kQ ± 20% at 20°C (6SoF)*

I

20°C (6SoF) I I

No I +-I

NGK BR9EV x 2 pcs. 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)

Resign type with noise suppressor 5 kQ ± 20% at 20°C (6SoF)

* SN4-20/MITSUBISH I

12V-100W 0.19 Q ± 10% at 20°C (68°F) (Yellow-Black)

Halogen light 12V-60/55W x 1 pc. 12V-SW!23W

-22 -

A.C. regulator: Model/Manufacturer Voltage

F" Tightening torque

Part to be tightened

[Engine] Spark plug Cylinder head Cylinder Flywheel magneto Crankcase upper and lower

Tightening sequence

~-$ 7 6

Thread size

M14 Pl.25 M8 Pl.25 M8 Pl.25 M16 Pl.0 M8 Pl.25

M6 Pl.0

·3 ·2

*TRIZ,50 HITACHI or S85 16B TOSHIBA 13.8 ± 0.5V

Tightening torque

28 Nm (2.8 m"kg, 20 ft°lb) 25 Nm (2.5 mokg, 18 ft-lb) 25 Nm (2.5 mokg, 18 ft-lb) 73 Nm (7.3 mokg, 53 ftolb) First: 10 Nm (1.0 mokg, 7 ft-lb) Final: 20 Nm (2.0 mokg, 15 ft"lb) First: 5 Nm (0.5 m"kg, 3.5 ft°lb) Final: 10 Nm (1.0 mokg, 7 ft°lb)

/ ·10

Remarks

- -------- ----- -

8-$ -$ 5 1. 4~ .9 11

~ ,

Ring weight and stay M6 Pl.0 10 Nm (1.0 mokg, 7.2 ft"lb) Use Neji Lock (Adhesive)

Flywheel magneto and stay M8 Pl.0 15Nm (l.5mokg,10.8ftolb) Use Neji Lock (Adhesive)

Fan shaft and pulley 2 M16 Pl.0 43 Nm (4.3 mokg, 31.1 ftolb) Starter pulley M8 Pl.25 23 Nm (2.3 mokg, 16.5 ft"lb) Crankcase and engine bracket M8 Pl.25 23 Nm (2.3 m"kg, 16.5 ft"lb)

[Drive and track suspension] Primary sliding sheave and cap M6 Pl.0 15 Nm (1.5 mokg, 10.8 ft-lb) Installation of primary sheave UNF 1/2" Initial: Use motor oil

120 Nm (12 m"kg, 87 ft"lb) Loosen once and retighten: 65 Nm (6.5 mokg, 47 ftolb)

Installation of secondary sheave M14 Pl.5 64 Nm (6.4 mokg, 46 ftolb) Bearing housing M8 Pl.25 23 Nm (2.3 m"kg, 16.5 ftolb) Brake caliper and houisng chain Ml0 Pl.25 48 Nm (4.8 m"kg, 35 ft"lb) Installation of drive chain sprocket M20 Pl.0 60 Nm (6.0 mokg, 43.5 ft-lb) Installation of driven chain sprocket Ml0 Pl.25 48 Nm (4.8 m"kg, 35 ftolb) Chain housing and frame M8 Pl.25 23 Nm (2.3 mokg, 16.5 ft"lb) Installation of front axle L.H. M22 Pl.0 85 Nm (8.5 mokg, 61.5 ft"lb) Front axle housing and frame M8 Pl.25 23 Nm (2.3 mokg, 16.5 ft"lb) Front pivot shaft Ml0 Pl.25 64 Nm (6.4 m"kg, 46 ft-lb) Rear pivot shaft Ml0 Pl.25 64 Nm (6.4 m"kg, 46 ftolb) Rear axle M14 Pl.25 80 Nm (8.0 mokg, 58 ft°lb) Sliding runner M6 Pl.0 2.5 Nm (0.25 mokg, 1.8 ftolb)

[Chassis] Engine mounting bolt Ml0 Pl.25 52 Nm (5.2 m"kg, 37.6 ft°lb) Steering column and gate M8 Pl.25 23 Nm (2.3 mokg, 16.5 ft"lb) Use lock washer

-23-

Part to be tightened Thread size Tightening torque Remarks

Steering gate M8 Pl.25 14 Nm (1.4 m·kg, 10 ft·lb) Steering relay rod adjusting nut Ml0 Pl.25 47 Nm (4.7 m·kg, 34 fHb) Steering lower bracket M8 Pl.25 23 Nm (2.3 m·kg, 16.5 ft·lb) Use lock washer Installation of steering column 1,2 M8 Pl.25 14.5Nm (1.45m·kg,10.5ft·lb) Steering relay ass'y Ml0 Pl.25 47 Nm (4.7 m·kg, 34 fHb) Use cotterpin Front shock absorber and bracket M8 Pl.25 21 Nm (2.1 m·kg, 15.2 ft·lb) Bracket 1, 2 set bolt M6 Pl.0 2 Nm (0.2 m·kg, 1.4 ft·lb) Front arm Ml0 Pl.25 16 Nm (1.6 m· kg, 11.6 ft·lb) Ski installation Ml0 Pl.25 43 Nm (4.3 m·kg, 31.1 ft·lb)

-24-

Particularly important information is distinguished in this manual by the following notations:

NOTE:

WARNING:

A NOTE provides key information to make procedures easier or clearer.

A CAUTION indicates special procedures that must be followed to avoid damage to the machine.

A WARNING indicates special procedures that must be followed to avoid injury to a machine operator or person inspecting or repairing the machine.

CONTENTS

I. NEW SERVICE PROCEDURE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3 V-BELTCLUTCH .. ..................................... 3

II. SPECiFiCATION ......................................... 23

MAINTENANCE AND LUBRICATION CHART

PERIODIC MAINTENANCE

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally 400km 800km 1,600 km necessary (250mi) (500mi) (1,000 mil

ENGINE:

Tightness of bolts and nuts 0

Bends, cracks and wear 0

Abnormal noise 0

Loose connection and breaks of fuel and pulse pipes 0

Loose connection and breaks of oil pipes 0

Loose connection and breaks of oil delivery pipe 0

Manual rope starter system 0

Carburetor:

• Operation of starter jet 0

• Mixing adjuster (pilot screwl 0

• Idling speed adjustment 0

Operation and adjustment of oil pump 0

Ignition timing 0

Engine compression 0

Cyl inder head/exhaust pipe decarbonization 0

Fan belt tension, damage 0

Spark plug condition, gap and cleaning 0

Tightening of the cylinder head**

DRIVE:


Wear on slide runners 0

Primary drive system 0

V·belt 0

Secondary drive system 0

Sheave distance 0

Sheave offset 0

Brake pad wear 0

Brake operation and adjustment 0

Guide wheel rubber 0

Wear of drive track wheel sprocket 0

Drive track adjustment 0

Breaks in drive track 0

Bends in front and rear axles 0

Checking of lock washers 0

Drive chain 'adjustment 0

Drive chain oil level 0

BODY:


Bends and cracks 0

Welded/riveted, jOints 0

Ski adjustment 0

Breaks in fuel tank 0


Fuel filter 0

Loose connection and breaks in fuel pipe 0

Breaks in oil tank 0

Oil filter 0

* * Retighten every 10hours from the first use.

-1-

Every


ELECTRICAL:

Wear, breakage of wire covering 0

Breaks in high-tension cord 0


Operation of engine stop switch 0

Operation of tether switch 0

Headlight 0

Taillight 0

Brake light 0

LUBRICATION INTERVALS

Every

Lubrication point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally Oil/Grease

400 km 800km 1,600 km necessary Brand name (250mi) (500 mil (1,000 mil

ENGINE:

Starter case 0

Oil pump control box 0 Aeroshell grease #7A or Esso Beacon 325 grease

Pump drive cover 0

Oil in the oil tank 0 Y AMALUBE 2-cycle oil

DRIVE:

Secondary shaft and 0 Molybdenum disulfide sl id i ng sh eave snowmobile grease

Front axle housing 0

Shaft 1 and shaft 2 Light all-purpose grease

(Slide rail) 0

Drive chain oil 0 Gear oil API GL-3 replacement SAE #75 or #80

BODY:

Steering column lower 0 Light all-purpose grease bearing

Steering column upper 0 Motor oil bearing

Steering links 0 Light all-purpose grease

Brake wire and stopper 0 0 Esso Beacon 325 grease and brake lever

Telescopic strut 0 suspension

-2-

I. NEW SERVICE PROCEDURE

CARBURETOR

Carburetor tuning 1. Standard specification

The carburetor is set at the factory to run at temperatures of O°C to -20°C (32° F to _4° F) at sea level. If the machine has to be operated under conditions other than specified above, the carburetor must be reset as required. Special care should be taken in carburetor setting so that pistons will not be holder or seized.

~ -300e _200e Altitude

(_22°F) (-4°FI

I

Sea level #155

- 600 m (2,000 ttl #150

- 1,200 m (4,000 ttl #145

- 1,SOO m (6,000 ttl #140

- 2,400 m (S,OOO ttl #135

- 3,000 m (10,000 ttl #130

V-BELT CLUTCH

NOTE: ____________ _

The following items under "4-1. Drive" in the SR540E Service Manual will be changed as described below: A. Sheave adjustment B. Primary sheave C. V-belt D. Secondary sheave

I ...

...

...

...

...

...

...

...

...

...

...

..

-3-

Main jet #150 Power jet #150 Slow jet #92 Pilot screw 2.0 turns out Starter jet #160

Float height 15~~ mm (059 +0.079 in) . -0.118

Idling engine speed 1,500 r/min

-100e oOe 100e 200e (14°FI (14°FI (50°FI (6SoFI

I I I I

#150 ... .. #145

#145 .... ... #140

#140 ... ... #135

#135 ~

... #130

#130 ... ... #125

#125 ~

... #120

A. SHEAVE ALIGNMENT

Sheave offset Place the sheave gauge against inner surfaces of the primary fixed sheave and the secondary sliding sheave. If the sheave gauge contacts the sheaves at four points as illustrated, the offset is correct.

NOTE: ____________ _

Be sure to remove the V-belt before adjusting the sheave offset.

Sheave offset: 13 ± 0.5 mm (0.51 ± 0.02 in)

~ Sheave gauge: YS-91047 (U.S.A.) 90890-01702

~ Sheave gauge adapter: YS-33274 90890-01718

Sheave distance If both ends of the primary shaft and the secondary shaft are aligned with the graduations, this indicates on the sheave gauge that the sheave distance is correct.

Sheave distance:

270~g mm (1O.6~g.12 in)

-4-

Adjustment If the center-to-center distance or offset is not within the specification, adjust it in the following manner:

1. Loosen the four engine mounting bolts. By moving the engine back and forth, adjust the sheave distance so that the center-to-center distance between the primary sheave mounting bolt and secondary sheave mounting bolt is equal to the sheave gauge set specified above.


1. Adjusting shim



Tightening torque: 52 Nm (5.2 m- kg, 37.6 ft-Ib)

NOTE: ___________ _

Select proper shims to be used at A and B. The total clearance at A and B should be 1.0 mm (0.4 in) or less.

(t = 1.0 mm) 90201-222FO (t = 0.5 mm)

90201-25526 (t = 2.0 mm) 90201-25527 (t = 1.0 mm) 90201-252F1 (t = 0.5 mm)

B. CLUTCH TUNING

The clutch may require tuning depending upon the area of operation and the desired handling characteristics. The clutch can be changed by changing engagement & shifting rpm. Clutch engagement rpm is defined as the engine speed where the machine first begins to move from a complete stop. Shifting rpm is the engine speed when the machine passes a point 200 - 300 m (650 -1,000 ft) from the starting position after the machine has been started at full-throttle from a dead stop.

Engine rpm

Clutch shifting rpm

CI utch engagement rpm

t

--

Good condition

Normally, when a machine reaches shift rpm, the vehicle splines Increases but the engine speed remains nearly constant. Under unfavorable conditions, however (wet snow, icy snow, hills, or rough terrain), engine speed can decrease after the engine has reached shifting rpm.

Engine rpm

Clutch shifting rpm


Bad condition

Travelled distance

I-------t--_- Travelled distance -Starting position 200 _ 300 m (650 -1,000 ttl Starting position 200 _ 300 m (650 -1,000 ft)

-5-

CLUTCH SETTING DATA

1. Standard specification

Engagement r.p.m.

Shifting r.p.m.

Parts No.

Set weight Primary spring

Spring constant

Color

O'ty Spider shim

Part No.

O'ty V-belt shim

Part No.

Mark Weight

Part No.

Parts No.

Twist angle Secondary spring

Spring hole No.

Color

S.t.d. spec High altitude spec

3,700 ± 200 4,200 ± 200

7,000 ± 200 +-

8U7-17643-00 8U7-17643-10

28.6 kg 46.2 kg

1.73 kg/mm 2.4 kg/mm

SILVER/RED SILVER/GREEN

1 p.c. +-

8 U7 -17654-00 +-

1 p.c. (t = 1.4 mm) +-

8U9-17687-00 +-

A-1 A - 1 (Modify)

8U7-17633-00 8U7-17633-10

90508-50571 +-

20° 50°

A - No.1 A- No.2

PINK +-

NOTE: ________________________________________________________ ___

The "High altitude spec" supplies to operation at an altitude of more than 1,500 meters (4,500 feet).

2. How to change clutch engagement rpms and clutch shifting rpms.

~ Clutch engagement r.p.m. Clutch shifting r.p.m.

Decreasing

Spring constant -Primary spring

Preload Decrease

Torsion spring -Secondary spring constant

Twist angle -

Primary clutch engagement rpm setting The factor which change the clutch engagement rpm is the primary spring preload. Therefore, the clutch engagement rpm can be

adjusted by replacing the primary spring itself.

Standard clutch engagement rpm:

3,500 - 3,900

-6-

Increasing Decreasing Increasing

- Decrease Increase

Increase - -

- Decrease Increase

- Smaller wind Greater wind

For high altitude: 4,000 - 4,400

Secondary clutch shifting rpm setting The secondary clutch must be tuned to match snow and weather conditions. Tuning the clutch keeps the engine operating in the proper rpm range.

Standard clutch shifting rpm:

6,800 - 7,200

Secondary spring setting 1. Secondary spring position

The spring seat is provided with four holes, No. 1 to 4, so that the secondary spring position can be changed as required.

2. Secondary spring tension The secondary spring tension can be changed by moving the spring position from the free position in order to reset the clutch shifting rpm as required. The four holes are spaced at intervals of 30°.

Course Trail and tour

Spring factor Position of spring seat and sliding sheave

Icy snow Std.

Packed snow Std.

Wet snow B - No. 1 or C - No.2

~ spring NO.1 No.2 No.3 No.4 Hole of sliding sheade

C 10° 40° 70° 100°

A 20° 50° 80° 110°

B 30° 60° 90° 120°

Winding the spring more (i.e., from 10° to 40°) will increase the clutch shifting rpm and vise versa. Snow conditions will also require a change of the spring tension in order to attain the standard shifting rpm. The spring tension must be greater on wet snow than on packed snow. Less tension is needed on icy snow.

3. Secondary spring setting

Twist

Std.

Std.

30° or 40°

-7-

Std. secondary spring: PIN: 90508-50571 Color code: Pink

Std. secondary spring position:

A - No.1

Std. secondary spring twist: 20°

The secondary spring settings are classified into two types as shown below. Select a proper setting according to operating conditions. (For the setting procedure, refer to "d. Secondary Sheave.")

Lake surface

Position of spring seat and Twist sliding sheave

Std. Std.

Std. Std.

Std. or B - No.1 Std. or 30°

Co PRIMARY SHEAVE

V-belt shim

173 Nm (17.3 mokg, 125 ftolbl

• ~ Oiling point

NOTE: X ~ No oiling or greasing is allowed.

Tightening torque:

Apply Loctite® #262 to the top four threads.

First tighten the bolt to a torque of A, then loosen it. Retighten bolt to a final torque of B.

A: 120 Nm (12 mokg, 87 ftolbl B: 58 Nm (5.8 mokg, 47 ftolbl

Sheave cap Sheave cap bolt

•

Loctite #262

Weight pin

-8-

Removal 1. Remove the drive guard, and remove the

V-belt. 2. Hold the fixed sheave with the primary

sheave holder and remove the clutch retaining bolt and washer. Drive the primary sheave off the crankshaft with the primary sheave puller.

To remove the clutch, a sheave puller and a sheave holder are required.

1. Sheave puller 2. Sheave holder


Primary sheave puller: YS-33272 (U.S.A.) 90890-01719

-9-

Disassembly 1. Loosen the six sheave cap bolts. 2. Remove the sheave cap and spring. 3. Remove the primary sheave by using the

clutch sprider separater.

Yamaha spider wrench: 90890-01711 YS-28890 (U.S.A.)

Center post: YS-33273 (cp = 14 mm)

1. Center post (YS·33273)

WARNING:

To loosen the spider, high torque is required and therefore, make sure the primary sheave, vise, and tools are tightely secured also take care not to crack the spider.

Do not use steal wool or a wire brush to clean components having a duralon bushing: damage will result it bushing is contacted with the steal wool or a wire brush.

Inspection 1. I nspect the tapered ends of the crank·

shaft and the primary fixed sheave for scraches. If either is severely scratched, replace it. If scratches are minor, burnish the component with emery cloth.

2. Bushings Check the primary sheave cap bushing and the sliding sheave bushing for wear. If worn beyond tolerance, replace the bushing, or cap assembly.

-10-

Bush inside Sheave cap Sliding sheave diameter

Standard 28.6 mm 41.7 mm (1.23 in) (1.64 in)

Wear limit 0.25 mm 0.25 mm (0.01 in) (0.01 in)

3. Weights Check the bushing bore inside diameter of each weight and its contact surface with the collar. If worn more than limits, replace them with new ones.

Bushing bore Contact surface with collar

Wear diameter (d) A B limit 6.7mm 0.5mm i.o mm

(0.26 in) (0.021 in) (0.04 in)

Contact surface with collar

4. Roller Check the inside diameter of the roller bushing, then check the contact surface of the roller and the weight. If either surface is worn unevenly or more than acceptable limits, replace them.

Bushing bore Contact surface Wear diameter (d) with weight (0) limit

9.9 mm (0.39 in) 13.0 mm (0.51 in)

Contact surface with weight

Uneven wear

-~

~===:::::j----t I ---r--d -0-----+-

I========l---t I __ ----1

If the outer surface of the roller is worn unevenly, the roller is probably seized to the pin. Be sure to check the roller pin.

5. Weight pins and roller pins Check both weight and roller pins. If metal dust collects on pins, remove it using sandpaper (#800 - #1,000). If the pin is damaged or bent, replace the pin with a new one.

6. Spider Check the contact surface of the spider with the slider. If it is worn more than limits or cracked, replace it with a new one.

Maximum clearance: 2.0 mm (0.08 in)

1. Wear limit

7. Primary spring Check the primary spring for damage or fatique, and replace it as required.

Assembly 1. Pay attention the following points when

replace the weight arm.

-11 -

a. Make sure the threads of the pivot bolt are clean and dry, and apply a generous amount of red loctite® #262 to the threads of each bolt.

b. Immediatly install new lock nuts on pivot bolts, and tighten them until they just touch the aluminum casting. Never reuse lock nuts.

Do not over tighten the pivot-bolt nuts; overtightening may cause binding of the weight arms. Check the operation of the weight arms after tightening the pivot-bolt nuts.

VVARNING:

To maintain the balance of the clutch, the pivot bolts all must be installed with their threaded portions pointing in a clockwise direction; see illustration 1.

ILLUSTRATION 1

2. Install the spider, sliding sheave and fixed sheave.

NOTE: Install the duralon bushing carefully so it is not damaged.

a. I nstall the sl iding sheave, spider shim, V-belt shim onto the fixed sheave.

b. Apply Loctite® #262 to the threaded portion of the fixed sheave.

Apply to the top four threads

Fixed sheave

Spider shim

Apply Loctite® #262 to:

J_~t==r 4 threads

Outer surface of bushing (large)

1. Loctite® should be applied only to the area specified. Never apply to the outer surface of the bushing (large) and other areas.

2. Do not use the clutch until the Loctite® has completely cured. Wait 24 hours before using the clutch.

c. Tightening the spider with special tool.


-12 -

WARNING:

Since tightening torque is high, make sure the primary sheave, vise, and tools are tightely secured. Also take care not to crack the spider.

3. Tighten the sheave cap bolts.


NOTE: ______________________ ___

Make sure the cap bolts are clean and dry. Apply blue Loctite® Lock N'Seal to the threads of the bolts.

Installing Hold the primary fixed sheave with the primary sheave holder, and torque the sheave bolt to specification.


Tightening torque:

Tighten the bolt to A to properly seat the primary sheave on the crankshaft. Loosen the bolt, then torque it to B, the final torque.

A: 120Nm(12m·kg,87ft·lb) B: 70 Nm (7.0 m' kg, 49 ft·lb)

D. SECONDARY SHEAVE

Jackshaft /4-7 Nm (0.4-0.7 m·kg, 2.9-~

/

Turn thel:scre~ securing the collar clockwise when viewed from the collar side, and lock the secondary

, shaft and collar, tighten the secondary sheave.

~~, ~~~

'" ~ '~ Plaine washer

CircliP __ ---W~ Spring seat

~ "00""',,, 'P';o,

Check the ramp shoes on secondary sliding ~~ Sliding sheave sheave for wear. Replace reamp shoes as re·1 ~ _ quired. '

X~- Fixed sheave

NOTE: .-'Greasing point

N.B.: .......... X-,...-No oiling or greasing is allowed

Removal 1. Apply the brake and remove the secon

dary sheave mounting bolt. 2. Remove the secondary sheave from the

jack shaft.

-13-

Disassembly

WARNING:

Use the Yamaha Secondary Compressor to contain the spring tension before removing the retaining circlip. DO NOT attempt this procedure unless you have the proper tools and understand the instructions thoroughly.

1. I nstall the secondary sheave onto the secondary sheave compressor so that the fixed sheave faces downward.

2. Hold the spring seat with the sheave compressor, screw in the wing nut.

3. Remove the circlip, and while screwing out the wing nut set the secondary spring free.

Secondary Compressor:

YS-28891 (U.S.A.) 90890-01712

1. Secondary sheave compressor

4. Remove the spring seat, secondary spring, sliding sheave and fixed sheave.

Inspection 1. Inspect both sheaves. If either is warped,

replace it. 2. Inspect the ramp shoes on the sliding

sheave, replace as necessary. 3. Check the sheave bushings for wear; re

place the sheave as required. 4. Check the spring. If it is fatigued or

damaged, replace it.

-14-

Assembly 1. Grease the secondary shaft, and sliding

sheave boss and mount the sliding sheave

on the shaft.

Recommended grease: Molybdenum disulfide snowmobile

grease

2. Install the secondary fixed sheave and sliding sheave onto the secondary sheave compressor.

3. Hook the end of the secondary spring onto the spring hole in the sliding

sheave. 4. Hook the other end of the secondary

spring onto the hole (indicated by No.) in the spring seat.

Std. spring position: A - No.1 hole

5. Install the plain washer and circlip.

6. Screw in the wing nut to the position at which the splined portion of the spring seat nearly alignes with the splined portion of the fixed sheave.

7. Bring the spring seat splines to align with the fixed sheave splines by hand.

NOTE: ____________ _

Make sure that the three cams of the spring seat are in a position where they can move into the guide hole in the sliding sheave cam.

8. Screw in the wing nut so that the spring seat is splined to the sliding sheave.

9. Screw in the wing nut to bring down the spring seat to a position where the spring seat cam does not contact the sliding sheave cam when they turn.

-4---- Spring seat cam

Sliding sheave cam

-15 -

10. Turn the sliding sheave the specified degrees in the counterclockwise direction, and screw in so that the spring seat engages with the sliding sheave.

Standard twist angle: 20°

11. Screw in the wing nut, and while pushing the spring seat, fit the circlip to the fixed sheave to lock the spring seat.

12. Install the secondary sheave assembly and adjust the sheave off-set.

Lubrication of transmission To keep the machine in the best operating condition, the sheaves should be lubricated with low temperature grease and motor oil periodically as illustrated.

+-. Oiling point

+- X Free from oil

+- Greasing point

-16-

1. Do not apply grease to the area marked X. For other parts, oiling is unnecessary.

2. When installing the primary sheave, clean the oil off the taPered portion of crankshaft using a lacquer thinner.

Eo FRONT SUSPENSION

Installation

2Nm (0.2 m-kg, 1.4 ftolb)

I Arm outside I

21 Nm (2.1 mokg, 15.2 ftolb)

NOTE: .. Greasing ... . pOint

(ESSO beacon 325)

-17-

'D-a-m-pe-r s-u-b-a-ss-em-~-IY-'- - -r~l--; --1 ~ I

i '~l I ,I

_J e9 --- . I ~--'

I I I I I I I I I I I I I I I I I I I L- __________ .J

43 Nm (4.3 m-kg, 31.1 ftolb)

F. REAR SUSPENSION

Removal

NOTE: ___________ _

It is advisable to loosen the track adjusting nut and the rear axle nut.

1. Remove the two front pivot shaft mounting bolts and four rear pivot shaft mounting bolts.

2. Remove the slide rail suspension assembly.

1. Front shock 2. Rear shock

Inspection 1. Check to see if slide runners are worn

excessively. If the slide runner thickness is less than specified value, replace slide runner.

Wear limit: 10 mm (0.4 in) Slide runner securing screw tightening torque:

4.5 Nm (0.45 m' kg, 3.3 ft·lb)

-18 -

-----.--- ---

1. Wear limit: 10 mm (0.4 in) 2. New:: 15 mm (0.6 in)

@

I

2. Check the suspension wheel for damage. If damaged, replace it.

"DE CARBON" type shock absorber

WARNING:

These shock absorbers contain highly pressurized nitrogen gas. Read and understand the following information before handling the shock absorber. The manufacturer cannot be held responsible for property damage or personal injury that may result from improper handling.

1. Do not tamper with or attempt to open the cylinder assembly. Injury may result.

2. Do not subject shock absorber to an open flame or other high heat. This may cause the unit to explode due to excessive gas pressure.

3. Do not deform or damage the cylinder in any way. Cylinder damage will result in poor damping performance.

4. Gas pressure must be released before disposing of the shock absorber. To do so, drill a 2 - 3 mm (0.08 - 0.12 in) hole through the cylinder wall at a point 10 - 15 mm (0.4 - 0.6 in) above the bottom of the cylinder.

10 -15 mm (0.4 -0.6 in)

2 -3 mm (0.08-0.12 in) "' 1-"" ' I

WARNING:

Wear eye protection to prevent eye damage from escaping gas and/or metal chips.

1. Check the rod, and if it is bent or damaged, replace the shock absorber.

2. Check for oil leakage. If oil leakage is evident, replace the shock absorber.

3. By compressing the shock absorber, check to see there is no gas leakage.

Slide rail suspension adjustment The setting of suspension greatly affects the stability and steering of the machine. Therefore, it is necessary to adjust the suspension setting according to course conditions and rider's driving technique.

1. Front stopper band setting The height (L) of the front suspension can be properly adjusted by changing the length of the stopper band.

Standard setting: No.1 hole from the bottom

Tightening torque: 3.8 Nm (0.38 m' kg, 2.75 ft·lb)

1. Stopper band

1. Stopper band

No.5 NO.4

No.3 No.2

No.1 (STD)

This adjustment will affect the stability and maneuverability of the machine.

Snow condition Length of Track side slip stopper band

Lower (No.5) Increase Hard packed

Std. (No.1) Normal

Lower Increase Soft deep snow

Std. (No.1) Normal

Rear stopper band setting The height (L) of the rear suspension can be properly adjusted by changing the length of the stopper band.

Standard setting: No.1 hole

Tightening torque: 3.8 Nm (0.38 m' kg, 2.75 ft·lb)

- 19--

Performance of Bumping and Riding comfort straight running pitching

Poor Less Poor

Normal Normal Normal

Good -- Poor

Normal -- Normal

1. Stopper band

No.5 No.4

No.3 No.2

No.1 (STD)

This adjustment will affect the stability and meneuverability of the machine.

i Handling Track side slip

Lower Hard Decrease

Std. (No.1) Normal Normla

Main arm adjustment The location of the main arm can be changed on this model. This helps to control acceleration when the machine pulls out.

- --- --------- -- - ---- - - - - -- --

1. Main arm 2. Lower 3. Upper (Std.)

Handling Performance of Sett i ng facto r straight running

Packed, wet Std. Normal Std. Normal

Ice snow No.2 Poor No.2 Increase

Std. Normal Std. Normal Deep snow

No.2 Poor No.2 Decrease

Rear spring The rear springs are determining factor in machine stability. Consider the ground surface condition and the rider's weight when setting rear springs. The suspension should be set as soft as possible, unless it impairs the stability of the machine. -20-

Performance of Bumping and Riding comfort

straight running pitching

Good More Poor

Normal Normal Normal

Front side spring

~ No.2

1. Normal riding (less gap) Std. weight rider (No.2)

2. Trail riding (more gap) Heavy weight rider

Rear side spring

~ No.4 No.1

1. Normal riding (less gap) 2. Trail riding (more gap) Std. weight rider (No.1) Heavy weight rider

Front side rear spring

~ Handling Track side slip

Increase Poor Decrease

Decrease Good Increase

Rear side rear spring

-------------Handling Track side slip

Increase Good Increase

Decrease Poor Decrease

Installation Grease the slide rail suspension as indicated by arrows in the illustration. For easy installation of the slide rail suspension in the frame, proceed as follows .

/ ... --- ---- -~-.--~--.-.--.--~- -~ -

I /

Hard packed Deep snow performance of +- Riding comfort straight running

Good Poor Poor

Poor Good Good

Performance of Riding comfort Heavy weight straight riding rider

Poor Poor Good

Good Good Poor

----.--.--.--------.-----.~-- ----_.-

1. Fully loosen the drive track adjusting screws.

2. Place the slide rail suspension into track and fit the forward pivot shaft using washers and bolts.

-21 -

NOTE: ___________ _

I nstall bolts finger-tight. Bolts will be tightened to proper torque when slide rail installation is complete.

3. Fit the rear pivot shaft to the frame. The rear pivot shaft is being forced toward the rear by the shock absorber.

NOTE: ________________________ _

When installation of slide rail is complete, tighten front and rear bolts to proper torque.

Tightening torque: Front pivot shaft mounting bolt:

64 Nm (6.4 m· kg, 46 ft·lb) Rear pivot shaft mounting bolts:

64 Nm (6.4 m· kg, 46 ft·lb)

4. Adjust the track tension by turning the track adjusting nuts.

-22-

SPECI FICATIONS

A. General * New specification (Compared with 1982 SR540F)

Model SR540G

Model: Model (I.B.M. No.) *SR540G (8U7) Frame 1.0. & Starting number *8R6-039101 Engine 1.0. & Starting number *SA535

Dimension: Overall length *2,675 mm (105.3 in) Overall width (Std.) 1,080 mm ( 42.5 in) Overall height (W/windshield) 970 mm ( 38.2 in)

B. Engine

Model SR540G


induction, twin cylinders Engine model SA535 Displacement 535 cc (32.65 cu.in) Bore x Stroke 73 x 64 mm (2.874 x 2.52 in) Effective compression ratio 6.0: 1 Starting system Recoil hand starter Ignition system C.D.1. Lubrication system "Autolube" oil injection

Cylinder head: Combustion chamber volume (with spark plug) *25.5 cc (1.68 cu.in) Compression chamber type Dome + Squich Head gasket thickness x Q'ty 0.5 mm (0.02 in) x 1 pc.


Piston: Piston skirt clearance (measuring point) 0.055 - 0.060 mm (0.0022 - 0.0024 in)

[17 mm (0.67 in) from piston skirt end] Piston oversize 1 st 73.25 mm (2.884 in)

2nd 73.50 mm (2.894 in) 3rd 73.75 mm (2.904 in) 4th 74.00 mm (2.913 in)

Piston pin outside diameter x Length cfJ 20 x 56 mm (cfJ 0.787 x 2.20 in)

Piston ring: Piston ring design Keyston'e Ring end gap (installed) 0.2 - 0.4 mm (0.008 - 0.016 in)




Crankshaft assembly width (F) 60 ~ g.osmm (2.362 ~ g.002 in)

Crankshaft deflection (D) 0·1: 0.03 mm (0.0012 in) 0·2: 0.04 mm (0.0016 in) 0·3: 0.04 mm (0.0016 in) 0-4: 0.05 mm (0.0020 in)

-23-

Model SR540G

Connecting rod big end side clearance (C) I 0.25 - 0.75 mm (0.010 - 0.030 in) Connecting rod small end deflection (P) Df- P 2.0 mm (0.079 in)

0-1 0-2 0-3 0-4

I~I! ! :

I 'J I ~ L ___ A_~-F-Crank pin outside diameter x Length cf> 24 x 59 mm (cf> 0.945 x 2.323 in) Crank pin type Solid shaft assembly type with serration Crank bearing type (left) x Q'ty #6306 special x 2 pcs. Crank bearing type (Center) x Q'ty #6206 special x 2 pcs. Crank bearing type (Right) x Q'ty #6206 special x 1 pc. Crank oil seal type (Left) x Q'ty FWJ-3278 9.5 TS x 1 pc. Crank oil seal type (Center) x Q'ty Labyrinth seal x 1 pc. Crank oil seal type (Right) x Q'ty FWJ-3248 10-1 TS x 1 pc.

Cooling fan: Fan belt tension 4 - 6 kg/8 mm (8.8 - 13.2 Ib/0.31 in)

Carburetor:: Type & Manufacturer/Quantity B044-38/KE I H I N/l pc. 1.0. Mark *8R601 Main jet (M.J.) *#150 Main air jet (M.A.J.) #180 Power jet (Pw.J.) #150 Power air jet (Pw.A.J.) #170 Slow jet (S.J.) #92 Slow air jet (S.A.J.) #100 Pilot screw (P.S.) 2.0 turns out Starter jet (St.J.) #160

Float height 15 + 2 mm (0.59 + 0.08 - 3 - 0.12

in)

Idling engine speed 1,500 r/min

*Main jet setting chart

~ -30°C -20°C -10"e oOe 10°C 20°C Altitude (-22°FI (-4°FI (14°FI (14°FI (50°FI (68°FI

I I I I I I • #150 ..

Sea level

F#155 .. . #145----

.. #145 ... - 600 m (2,000 ttl

r---#150 .. .. #140 .. #140 .. - 1 ,200 m (4,000 ttl

r---#145 .. .. #135

.. #135 .. - 1,800 m (6,000 ttl

r---#140 .. .. #130

• #130 .. - 2,400 m (8,000 ttl

-#135 .. • #125----.. #125 .. - 3,000 m (10,000 ttl

-#130 • .. #120

-24-

Model


lubrication: Autolube pump - Color code Autolube pump - Minimum stroke Autolube pump - Maximum stroke Autolube pump - Reduction ratio Autolube pump - Output Min'/200 strokes Autolube pump - Output Max./200 strokes Autolube pump wire free play Oil tank capacity Oil grade


Transmission: Type Drive ratio Engagement rpm Shifting rpm Primary spring:

Part No. Color code


Model

Secondary spring pre·load (twist) Sheave distance

Sheave off-set V-belt width and outer line length V-belt wear limit

Track suspension: Type Damper type Spring color code (Front) Spring color code (Rear) Slide runner wear limit Track width Track deflection length on ground Wheel sprocket material and number of teeth Stopper band length (Front) Stopper band length (Rear)


Free play


SR540G

V type 0.6 mm (0.024 in) 12 ± 0.2 mm (0.4724 ± 0.0079 in)

Gray 0.20 - 0.25 mm (0.0079 - 0.0098 in) 1.65 - 1.87 mm (0.0650 - 0.0736 in) 1/36 0.95 - 1.19 cc (0.0321 - 0.0402 oz) 7.84 - 8.89 cc (0.2651 - 0.3006 oz) 25 ± 1 mm (0.98 ± 0.04 in) at idle 2.5 l (2.6 US qt, 2.2 Imp qt) Yamalube 2-cycle

SR540G

V-belt automatic centrifugal engagement 3.5: 1 - 1 : 1 *3,500 - 3,900 rpm *6,800 - 7,200 rpm

*8U7 -17643-00 *Silver - Red

*90508-50571 *Pink *200 (No.1)

270~~ mm(10.63~g.11 in)

*13 ± 0.5 mm (0.433 ± 0.020 in) 31.6 x 1,099 mm (1.24 x 43.3 in) 26 mm (1.02 in)

Slide rail suspension Oil and gas damper No painted No painted 10 mm (0.394 in) 381 mm (15 in)

25 - 30 mm/10 kg (0.98 -1.18 in/22Ib) 902 mm (35.5 in) Double polyethylene 9 teeth *250 mm ( 9.84 in) (No.1 hole from the bottom) *267 mm (10.51 in) (No.1 hole from the bottom)

Chain (#35-3) 17/31 (1 : 1.824) 9.525 mm (0.375 in) x 66l

10~~ mm (0.4~g:~8in) 250 cc (8.5 oz) Gear oil API "Gl-3" (SAE #75 - 80)

-25-

Model SR540G

Brake: Type Floating disc type Brake pad thickness 5 mm (0.20 in) Brake pad wear limit 1.0 mm (0.04 in) Brake cable "L" distance 57 mm (2.24 in) Clearance between lining pad and disc 0.15 - 0.3 mm (0.006 - 0.012 in)

D. Chassis

Model SR540G


Steering system; Caster (ski column) 25°

Chamber 0° Ski length x Width x Thickness 980 x 120 x 2 mm (38.6 x 4.7 x 0.08 in) Ski stance 880 mm (34.6 in) Ski toe-out o mm (0 in) Steering linkage type Tie-rod Steering angle Right: 46°

Left: 46° Lock to lock angle (Ski) Right ski L: 27.9° R: 33.4°

Left ski L: 33.4° R: 27.9°


Fuel tank:

I Capacity 26.6 L (5.9 Imp gal, 7.0 US gal) Fuel grade Regular gasoline

E. Electrical

Model SR540G

Ignition system: Type - Flywheel magneto (C.D.1. Type)

Model/Manu factu rer F3T352/MITSUBISHI Voltage 12V Charging coil resistance 5900 ± 10% at 20°C (68°F) (Brown - Black) Pulser coil resistance 15.10 ± 10% at 20°C (68°F) (White/Red - Black)

Ignition timing: B.T.D.C. 1.5 mm (0.059 in), 15° at 7,000 r/min

Ignition coil: HITACHI ! TOYO-DENSO Manufacturer/Model/Quantity CM62-21 /1 pc. YW-51/1 pc. Spark gap 9 mm (0.4 in)/300 rpm +-

11 mm (0.6 in)/3,000 rpm +-

Primary winding resistance 0.150 ± 10% at 0.120 ± 10% at 20°C (68°F) 20°C (68°F)

Secondary winding resistance 3.5 kO ± 10% at 4.0 kO ± 20% at 20°C (68°F) 20°C (68°F)

Diode (Yes or No) No +-

Spark plug: Type & Quality NGK BR9EV x 2 pcs. Spark plug gap 0.7 - 0.8 mm (0.028 - 0.031 in)

-26-

Model SR540G

Spark plug cap: Type Resign type with noise suppressor Noise suppressor resistance 5 k,Q ± 20% at 20°C (68°F)

C.D.1. unit: Model/Manufacturer 8N4-20/M ITSUBISH I

Lighting system: Lighting output 12V-100W Lighting coil resistance 0.19,Q ± 10% at 20°C (68°F) (Yellow - Black) Headlight type Halogen light

Bulb wattage/Q'ty 12V -60/55W x 1 pc. Tail/Brake light wattage 12V-8W/23W

A.C. regulator: I

Model/Manufacturer TRIZ-50/HITACHI or S85 16B/TOSHIBA Voltage 13.8 ± 0.5V


Part to be tightened Thread size Tightening torque

Remarks Nm mokg ftolb

Engine: Spark plug M14 P1.25 28 2.8 20 Cylinder head M8 P1.25 25 2.5 18 Cylinder M8 P1.25 25 2.5 18 Flywheel magneto M16 P1.0 73 7.3 53 Crankcase upper and lower: First M8 P1.25 10 1.0 7

Final M8 P1.25 20 2.0 15 Tightening sequence: First M6 P1.0 5 0.5 3.5

Final M6 P1.0 10 1.0 7

I ~-$

$3 4-2 ·10 7 6 - . - " .. __ ... _- - - ------ ---

8~~ 5 1. 4~ $9

11

~

Ring weight and stay M6 P1.0 10 1.0 7 Use Loctite® (Adhesive)

Flywheel magneto and stay M8 P1.0 15 1.5 10.8 Use Loctite® (Adhesive)

Fan shaft and pulley 2 M16 P1.0 43 4.3 31.1 Starter pulley M8 P1.25 23 2.3 16.5 Crankcase and engine bracket M8 P1.25 23 2.3 16.5

Drive and track suspension: Primary sliding sheave and cap M6 P1.0 15 1.5 10.8 Installation of primary sheave:

Initial UNF 1/2" 120 12 87 Use m~tor oil Loosen once and retighten UNF 1/2" 65 6.5 47

Installation of secondary sheave M14 P1.5 64 6.4 46 Bearing housing M8 P1:25 23 2.3 16.5 Brake caliper and housing chain M10 P1.25 48 4.8 35 Installation of drive chain sprocket M20 P1.0 60 6.0 43.5 Installation of driven chain sprocket M10 P1.25 48 4.8 35 Chain housing and frame M8 P1.25 23 2.3 16.5 Installation of front axle L.H. M22 P1.0 85 8.5 61.5

-27 -


Remarks Nm m'kg ft'lb

Front axle housing and frame MS Pl.25 23 2.3 16.5 Front pivot shaft Ml0 Pl.25 64 6.4 46 Rear pivot shaft Ml0 Pl.25 64 6.4 46 Rear axle M14 Plo25 SO S.O 5S Sliding runner M6 PLO 2.5 0.25 1.S

Chassis: Engine mounting bolt Ml0 Pl.25 52 5.2 37.6 Steering column and gate MS Pl.25 23 2.3 16.5 Use lock washer Steering gate MS Pl.25 14 1.4 10 Steering relay rod adjusting nut Ml0 Pl.25 47 4.7 34 Steering lower bracket MS Pl.25 23 2.3 16.5 Use lock washer Installation of steering column 1,2 MS Pl.25 14.5 1.45 10.5 Steering relay ass'y Ml0 Pl.25 47 4.7 34 Use cotterpin Front shock absorber and bracket MS Pl.25 21 2.1 15.2 Bracket 1, 2 set bolt M6 PLO 2 0.2 1.4 Front arm Ml0 Pl.25 16 1.6 11.6 Ski installation Ml0 Pl.25 43 4.3 31.1

-2S -

MAINTENANCE AND LUBRICATION CHART

PERIODIC MAINTENANCE

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally 400 km 800 km 1,600 km necessary (250mi) (500mi) (1,000 mil

ENGINE:


Bends, cracks and wear 0

Abnormal noise 0

Loose connection and breaks of fuel and pulse pipes 0

Loose connection and breaks of oil pipes 0

Loose connection and breaks of oil delivery pipe 0

Manual rope starter system 0

Carburetor:

• Operation of starter jet 0

• Mixing adjuster (pilot screw) 0

• Idling speed adjustment 0

Operation and adjustment of oil pump 0

Ignition timing 0

Engine compression 0

Cylinder head/exhaust pipe decarbonization 0

Fan belt tension, damage 0

Spark plug condition, gap and cleaning 0

Tightening of the cylinder head**

DRIVE:


Wear on slide runners 0

Primary drive system 0

V-belt 0

Secondary drive system 0

Sheave distance 0

Sheave offset 0

Brake pad wear 0

Brake operation and adjustment 0

Guide wheel rubber 0

Wear of drive track wheel sprocket 0

Drive track adjustment 0

Breaks in drive track 0

Bends in front and rear axles 0

Checking of lock washers 0

Drive chain adjustment 0

Drive chain oil level 0

BODY:


Bends and cracks 0

Welded/riveted, joints 0

Ski adjustment 0

Breaks in fuel tank 0


Fuel filter 0

Loose connection and breaks in fuel pipe 0

Breaks in oil tank 0

Oil filter 0

* * Retighten every 1 Ohours from the first use.

-1-

Every


ELECTRICAL:

Wear, breakage of wire covering 0

Breaks in high-tension cord 0


Operation of engine stop switch 0

Operation of tether switch 0

Headlight 0

Taillight 0

Brake light 0

LUBRICATION INTERVALS

Every

Lubrication point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally Oil/Grease 400 km 800km 1,600 km necessary Brand name (250mi) (500mi) (1,000 mil

ENGINE:

Starter case 0

Oil pump control box 0 Aeroshell grease #7A or Esso Beacon 325 grease

Pump drive cover 0

Oil in the oil tank 0 Y AMALUBE 2-cycle oil

DRIVE:

Secondary shaft and 0 Molybdenum disulfide sl id ing sheave snowmobile grease

Front axle housing 0

Shaft 1 and shaft 2 Light all-purpose grease

(Slide rail) 0

Drive chain oil 0 Gear oil API GL-3 replacement SAE #75 or #80

BODY: -

Steering column lower 0 Light all·purpose grease bearing

Steering column upper 0 Motor oil bearing

Steering links 0 Light all-purpose grease

Brake wire and stopper 0 0 Esso Beacon 325 grease and brake lever

Telescopic strut 0 suspension

-2-

NEW SERVICE PROCEDURE SECONDARY SHEAVE V-belt shim There are two V-belt shims between the fixed and sliding sheaves. By removing one or both of the shims when the V-belt is worn you can obtain the same reduction ratio (3.5:1) as a new V-belt.

Fixed sheave - ---

V-belt

V-belt shim (2 pes.)

Spare V-belt shim

1. V-belt shim (2 pes.) -

1. When the V-belt width is wron to 30.6 mm (1.20 in): Remove one shim.

NOTE: ______________________ __

The removed shim can be reused when the V-belt has been replaced, so it should be stored between the sliding sheave and spring seat.

-3-

- 2 mm (0.0787 in)

Sliding sheave

Spring seat

2. Spare V-belt shim

V-belt width NEW: 31.6 mm (1.24 in)

2. When the V-belt width is further worn to 29.6 mm (1.17 in): Remove both two shims.

3. When the V-belt width is further worn to 26.0 mm (1.02 in): Replace the V-belt with a new one and install the two shims.

WARNING:

When replacing the V-belt, be sure to install the two shims and check to see that there is a 2 mm (0.0787 in) clearance between the fixed and sliding sheaves. If no shims are installed, the clutch-in rpm will drop; this may cause the snowmobile to lurch when the engine is started.

Clutch alignment To achieve clutch alignment, both the sheave distance and sheave offset must be properly adjusted. When they are properly adjusted, the clutch can function correctly.

Standard sheave distance:

. 270 ~g mm (10.63 ~g.11 in)

Standard sheave offset: 11 ± 0.5 mm (0.433 ± 0.0196 in)

Tool name Tool No.

Sheave gauge YS-91047

1. Sheave distance 2. Sheave offset

1. Removing the V-belt a. Turn the secondary sliding sheave clock

wise when facing toward the chain housing, and push the sliding sheave.

b. When the sliding sheave is pushed, it separates from the fixed sheave so that the V-belt can be removed from the fixed sheave side.

-4-

2. Loosen the four engine mounting bolts. 3. Adjust sheave guage to the specified

standard sheave distance. By moving the engine back and forth, adjust the sheave distance so that the center-tocenter distance between the primary sheave mounting bolt and secondary sheave mounting bolt is equal to the specified standard sheave distance.

1. Sheave gauge


NOTE: ______________________ ___

• When the sheave distance and offset are properly adjusted, the sheaves are in contact with the sheave gauge at the four points as illustrated.

• The secondary sheave mounting bolt should be tightened to the following specification.

Tightening torque: 60 Nm (6.0 m- kg, 43 ft-Ib)

• Select proper shims to be used at A and B. The total clearance at A and B should be 1.0 mm (0.4 in) or less.

It = 1.0 mm) 90201-222FO (t = 0.5 mm)

90201-25526 It = 2.0 mm) 90201-25527 (t = 1.0 mm) 90201-252F1 It = 0.5 mm)



Tightening torque: 52 Nm (5.2 m o kg, 37 ft-Ib)

7. I nstall the V -belt.

-5-

SUSPENSION Front stopper band setting

1. Stopper band

CD

1. Stopper band

No.5 No.4

No.3 No.2

No.1 (STD)

No.O

Snow condition Length of

Track side slip Performance of Bumping and Riding comfort

stopper band

Lower (No.5) Increase

Hard packed Std. (No.1) Normal

Higher (No. 0) Decrease

Lower Increase

Soft deep snow Std. (No.1) Normal

Higher (No. 0) Decrease

Shock absorber spring adjustment Screwing in the spring seats on the front and rear shock absorbers shortens the spring set length, thus making the shock absorbers hard. Screwing them out softens the shock absorbers. Adjust, as required.

straight running

poor

Normal

Good

Good

Normal

Poor

'-~---------Spring set length--------... -~I

I~:~~:":"'::::~ ::::::::::=~=====":'.:A

7-Spring Shock absorber Spring seat

~ Front shock Rear shock absorber absorber

Std. spring 196 mm 269 mm set length (7.72 in) (10.6 in)

-6-

pitching

Less Poor

Normal Normal

More Good

- Poor

- Normal

- Good

Lock nut

1. Front shock absorber spring

----- STIFFER 4 ~ SOFTER

Spring set Mini. Max. 184 mm .. ~ 200 mm length (7.24 in) (7.87 in)

~ Hard packed Deep snow

Handling Track side slip performance of ~

Riding comfort straight running

Increase Good Increase Poor Poor Good

Decrease Poor Decrease Good Good Poor

2. Rear shock absorber spring

------ STIFFER .. ~ SOFTER

Spring set Mini. Max. 269 mm • ~ 269mm length (10.6 in) (10.6 in)

s~ Handling Track side slip Performance of

Riding comfort Heavy weight

straight riding rider

Increase Poor Decrease Good Good Poor

Decrease Good Increase Poor Poor Good

-7-

SPECI FICATIONS

A. General

Model SR540H

Model: Model (I.B.M. No.) SR540H (8V9) Frame I.D. & Starting number 8V9·060101 Engine I.D. & Starting number SA535-060 101

Dimension: Overall length 2,675 mm (104.3 in) Overall width (Std.) 1,080 mm ( 42.5 in) Overall height (W/windshield) 970 mm ( 38.2 in)

B. Engine

Model SR540H


induction, twin cylinders Engine model SA535 Displacement 535 cc (32.65 cu.in) Bore x Stroke 73 x 64 mm (2.874 x 2.52 in) Effective compression ratio 6.0: 1 Starting system Recoil hand starter Ignition system C.D.1. Lubrication system "Autolube" oil injection

Cylinder head: Combustion chamber volume (with spark plug) 25.5 cc (1.68 cu.in) Compression chamber type Dome + Squich Head gasket thickness x Q'ty 0.5 mm (0.02 in) x 1 pc.


Piston: Piston skirt clearance (measuring point) 0.055 ~ 0.060 mm (0.0022 ~ 0.0024 in)

[17 mm (0.67 in) from piston skirt end] Piston oversize 1 st 73.25 mm (2.884 in)

2nd 73.50 mm- (2.894 in) Piston pin outside diameter x Length I/J 20 x 56 mm (I/J 0.787 x 2.20 in)

Piston ring: Piston ring design Keystone Ring end gap (installed) 0.2 ~ 0.4 mm (0.008 ~ 0.016 in)




Crankshaft assembly width (F) 60+0 ( +0· _ 0.05mm 2.362 _ 0.002'")

Crankshaft deflection (D) D-1: 0.03 mm (0.0012 in) D-2: 0.04 mm (0.0016 in) D-3: 0.04 mm (0.0016 in) D4: 0.05 mm (0.0020 in)

-8-

Model SR540H

Connecting rod big end side clearance (C) I 0.25 - 0.75 mm (0.010 - 0.030 in) Connecting rod small end deflection (P) QI- P 2.0 mm (0.079 in)

0·, 0-2 0-3 0-4 97mm C "93mm

Crank pin outside diameter x Length if> 24 x 59 mm (if> 0.945 x 2.323 in) Crank pin type Solid shaft assembly type with serration Crank bearing type (left) x Q'ty #6306 special x 2 pes. Crank bearing type (Center) x Q'ty #6206 special x 2 pcs. Crank bearing type (Right) x Q'ty #6206 special x 1 pc. Crank oil seal type (Left) x Q'ty FWJ-32 789.5 TS x 1 pc. Crank oil seal type (Center) x Q'ty Labyrinth seal x 1 pc. Crank oil seal type (Right) x Q'ty FWJ-3248 10-1 TS x 1 pc.

Cooling fan: Fan belt tension 4 - 6 kg/8 mm (8.8 - 13.2 Ib/0.31 in)

Carburetor: Type & Manufacturer/Quantity BD44-38/KE I HI N/1 pc. I.D. Mark 8R601 Main jet (M.J.) #150 Main air jet (M.A.J.) #180 Power jet (Pw.J.) #150 Power air jet (Pw.A.J.) #170 Slow jet (S.J.) #92 Slow air jet (SAJ.) #100 Pilot screw (P.S.) 2.0 turns out Starter jet (St.J.) #160 Float height 12 - 17 mm (0.47 - 0.67 in) Idling engine speed 1,500 r/min

Main jet setting chart

~ -30oe _20oe _1Oo e oOe 200e 100e Altitude (_22°F) (--4°F) (14°F) (32°F) (50°F) (68°F)"

I I I I I I .. #150 ~

Sea level f---#155 .. .. #145 .. #145 ..

- 600 m (2,000 ft) f---#150 .. .. #140 .. #140 ..

- 1,200 m (4,000 ft) 1---#145 ,.. .. #135 .. #135 ..

- 1,800 m (6,000 tt) 1---#140 .. .. #130 .. #130 ..

- 2,400 m (8,000 ft) f---#135 ,.. .. #125 .. #125 ..

- 3,000 m (10,000 ft) f---#130 ,.. .. #120

-9-

Model


Lubrication: Autolube pump - Color code Autolube pump - Minimum stroke Autolube pump - Maximum stroke Autolube pump - Reduction ratio Autolube pump - Output Min.l200 strokes Autolube pump - Output Max.l200 strokes Autolube pump wire free play Oil tank capacity Oil grade

c. Drive and track suspension

Transmission: Type Drive ratio Engagement rpm Shifting rpm Primary spring:

Part No. Color code


Model

Secondary spring pre·load (twist) Sheave distance

Sheave off-set V-belt width and outer line length V-belt wear limit

Track suspension: Type Damper type Spring color code (Front) Spring color code (Rear) Slide runner wear limit Track width Track deflection Length on ground Wheel sprocket material and number of teeth Stopper band length (Front) Stopper band length (Rear)


Free play


SR540H

V type 0.6 mm (0.024 in) 12 ± 0.2 mm (0.4724 ± 0.0079 in)

Green 0.20 - 0.25 mm (0.0079 - 0.0098 in) 1.65 - 1.87 mm (0.0650 - 0.0736 in) 1/36 0.95 -1.19 cc (0.0321 - 0.0402 oz) 7.84 - 8.89 cc (0.2651 - 0.3006 oz) 25 ± 1 mm (0.98 ± 0.04 in) at idle 2.5 L (2.6 US qt, 2.2 Imp qt) Yamalube 2-cycle

SR540H

V-belt automatic centrifugal engagement 3.5: 1 ~ 1 : 1 3,500 - 3,900 rpm 6,800 - 7,200 rpm

8U7-17643-00 Silver - Red

90508-50571 Pink 30° (No.1)

270~~ mm(10.63~g.11 in)

11 ± 0.5 mm (0.433 ± 0.020 in) 31.6 x 1,099 mm (1.24 x 43.3 in) 26 mm (1.02 in)

Slide rail suspension Oil and gas damper No painted No painted 10 mm (0.394 in) 381 mm (15 in) 25 ~ 30 mm/10 kg (0.98 ~ 1.18 in/22 Ib) 902 mm (35.5 in) Double polyethylene 9 teeth 250 mm ( 9.84 in) (No.1 hole from the bottom) 267 mm (10.43 in) (No.1 hole from the bottom)

Chain (#35-3) 17/31 (1 : 1.824) 9.525 mm (0.375 in) x 66L

1 0 + 5 (0 4 + 0.2 . ) _ 2 mm . _ o.oa ln

250 cc (8.5 oz) Gear oil API "GL-3" (SAE #75 ~ 80)

-10 -

Model SR540H

Brake: Type Floating disc type Brake pad thickness 5 mm (0.20 in) Brake pad wear limit 1.0 mm (0.04 in) Brake cable "L" distance 57 mm (2.24 in) Clearance between lining pad and disc 0.15 - 0.3 mm (0.006 - 0.012 in)

D. Chassis

Model SR540H


Steering system; Caster (ski column) 25°

Chamber 0° Ski length x Width x Thickness 980 x 120 x 2 mm (38.6 x 4.7 x O.OB in) Ski stance 880 mm (34.6 in) Ski toe-out o mm (0 in) Steering linkage type Tie-rod Steering angle Right: 46°

Left: 46° Lock to lock angle (Ski) Right ski L: 27.9° R: 33.4°

Left ski L: 33.4° R: 27.9°


Fuel tank: Capacity 26.6 L (5.9 Imp gal, 7.0 US gal) Fuel grade Regular gasoline

E. Electrical

Model SR540H

Ignition system: Type - Flywheel magneto (C.D.I. Type)

Model/Manufacturer F3T352/MITSUBISHI Voltage 12V Charging coil resistance 1,29012 ± 10% at 20°C (68°F) (Brown - Black) Pulser coil resistance 1712 ± 10% at 20°C (6BoF) (White/Red - Black)

Ignition timing: B.T.D.C. 1.5 mm (0.059 in), 15° at 7,000 r/min

Ignition coil: HITACHI i TOYO·DENSO Manufacturer/Model/Quantity CM62-21 /1 pc. I

I YW-51/1 pc. Spark gap 9 mm (0.4 in)/300 rpm I

I+-

11 mm (0.6 in)/3,000 rpm: +-

Primary winding resistance 0.15n ± 10% at I 0.12n ± 10% at 20°C (68°F) : 20°C (6BoF)

Secondary winding resistance 3.5 kn ± 10% at i 4.0 kn ± 20% at 20°C (68°F) 120°C (6BoF)

I Diode (Yes or No) No I+-

Spark plug: Type & Quality NGK BR9EV x 2 pcs. Spark plug gap 0.7 - O.B mm (0.028 - 0.031 in)

-11 -

Model SR540H

Spark plug cap: Type Resign type with noise suppressor Noise suppressor resistance 5 kn ± 20% at 20°C (68°F)

C.D.1. unit: Model/Manufacturer 8N4·20/M ITSUB ISH I

Lighting system: Lighting output 12V·l00W Lighting coil resistance 0.19n ± 10% at 20°C (68°F) (Yellow - Black) Headlight type Halogen light

Bulb wattage/O'ty 12V -60/55W x 1 pc.

Tail/Brake light wattage 12V-8W/23W Grip heater coil resistance 0.66n ± 10% at 20°C (68°F) (Yellow/Black - Black)

A.C. regulator: Model /M anufactu rer TRIZ-50/HITACHI or S85 16B/TOSHIBA Voltage 13.8 ± 0.5V



Remarks Nm m'kg ft'lb

Engine: Spark plug M14 Pl.25 28 2.8 20 Cylinder head M8 Pl.25 25 2.5 18 Cylinder M8 Pl.25 25 2.5 18 Flywheel magneto M16 Pl.0 73 7.3 53 Crankcase upper and lower: First M8 Pl.25 10 1.0 7

Final M8 Pl.25 20 2.0 15 Tightening sequence: First M6 Pl.0 5 0.5 3.5

Final I M6 Pl.0 10 1.0 7

/ ~~ ~3 ·2 -$-10 7 6

-

8~~5 1. 4'- ~9

11

~

Ring weight and stay M6 Pl.0 10 1.0 7 Use Loctite® Flywheel magneto and stay M8 PloD 15 1.5 10.8 Use Loctite® Fan shaft and pulley 2 M16 Pl.0 43 4.3 31.1 Starter pulley M8 Pl.25 23 2.3 16.5 Crankcase and engine bracket M8 Pl.25 23 2.3 16.5

Drive and track suspension: Primary sliding sheave and cap M6 Pl.0 15 1.5 10.8 Installation of primary sheave:

Initial UNF 1/2" 120 12 87 Use motor oil Loosen once and retighten UNF 1/2" 65 6.5 47

Installation of secondary sheave M14 Pl.5 60 6.0 43 Bearing housing M8 Pl.25 23 2.3 16.5 Brake caliper and housing chain Ml0 Pl.25 48 4.8 35 Installation of drive chain sprocket M20 P1.0 60 6.0 43.5 Installation of driven chain sprocket Ml0 Pl.25 48 4.8 35 Chain housing and frame M8 Pl.25 23 2.3 16.5 Installation of front axle L.H. M22 Pl.0 85 8.5 61.5

-12 -


Remarks Nm mokg ftolb

Front axle housing and frame MB P1.25 23 2.3 16.5 Front pivot shaft M10 P1.25 64 6.4 46 Rear pivot shaft M10 P1.25 64 6.4 46 Rear axle M14 P1.25 BO B.O 5B Sliding runner M6 P1.0 2.5 0.25 1.B

Chassis: Engine mounting bolt M10 P1.25 52 5.2 37.6 Steering column and gate MB P1.25 23 2.3 16.5 Use lock washer Steering gate MB P1.25 14 1.4 10 Steering relay rod adjusting nut M10 P1.25 47 4.7 34 Steering lower bracket MB P1.25 23 2.3 16.5 Use lock washer Installation of steering column 1,2 MB P1.25 14.5 1.45 10.5 Steering relay ass'y M10 P1.25 47 4.7 34 Use cotterpin Front shock absorber and bracket MB P1.25 21 2.1 15.2 Bracket 1 , 2 set bolt M6 P1.0 2 0.2 1.4 Front arm M10 P1.25 16 1.6 11.6 Ski installation M10 P1.25 43 4.3 31.1

-13 -

~

I

Wiring diagram Tachometer (12V 3.4W)

~r------li9ht ~

Speedometer light ~ ~ ~ Oil caution light (12V 3.41) _ _ _ I (12V 3.4W)

L-,_

Color code L ...... Blue Y ...... Yellow O ...... Orange G ...... Green

, B ...... Black , G/Y .... GreenlYeliow . B/R .... Black/Red

B/W .... Black/White Br ...... Brown W/R .... White/Red R ...... Red Y/B .... Yellow/Black

Opt. (Grip heater)

Headlight (12V SOW/SSW)

cn ~Y :~~ ~Q B Y/B II q T.;,~"k.,;""

t I r,m I I f l-~IY 11-- I! I ~ __ 3 Bj~~ii33W1

B/W

Main switch

Headlight beam switch ~

~ L-G-

G Y , . Y-

Br~e li:~~:~~t~h = _~~J G/Y

G/Y

G I B/R

1---' I I

Oil level switch

C.D.I. magneto

o-D::::J-O

<=J.

-=-Ignition coil

C.D.I. unit

1981-1991 yamaha srv540 snowmobiles (1)

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