pulse crankcase driven fuel pump fuel system...pulse crankcase driven fuel pump 90-889785 april 2003...

3A

PULSE CRANKCASE DRIVEN FUEL PUMP

90-889785 APRIL 2003 Page 3A-1

FUEL SYSTEMSection 3A – Pulse Crankcase Driven Fuel Pump

Table of Contents

Specifications 3A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . Special Tools 3A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel Pump 3A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel Pump Description/Operation 3A-3. . . . . . . . . Checking for Restricted Fuel Flow Causedby Anti-Siphon Valves 3A-3. . . . . . . . . . . . . . . . . . . .

Checking Fuel Pump Lift (Vacuum) 3A-4. . . . . . . . Vacuum Test Troubleshooting 3A-4. . . . . . . . . . Testing Fuel Pump 3A-5. . . . . . . . . . . . . . . . . . . .

Fuel Pump Removal/Disassembly 3A-6. . . . . . . . . Cleaning/Inspection 3A-7. . . . . . . . . . . . . . . . . . . Reassembly/lnstallation 3A-7. . . . . . . . . . . . . . .

Specifications

Model 75/90/115

FUELSYSTEM

Fuel Pressure Crankcase Pump

– @ Idle

– @ WOT

Normal – 13.7 - 20.5 kPa (2-3 psi)Minimum – 6.8 kPa (1 psi)

Normal – 41.0 - 54.8 kPa (8-10 psi)Maximum – 68.5 kPa (10 psi)

Minimum –4 psi (27.4 kPa)

NOTE: Electric fuel pump pressure, if used in conjunction with engine mechanical fuelpump, must be limited to no more than 27.4 kPa (4 psi).

Special Tools

Fuel Pressure/Vacuum Gauge 0 – 103.4 kPa (0-15

psi)

Obtain Locally

ob57721


Page 3A-2 90-889785 APRIL 2003

Fuel Pump

REFTORQUE

REF.NO. QTY. DESCRIPTION lb-in lb-ft Nm.

– 1 FUEL PUMP ASSEMBLY1 1 FUEL PUMP2 1 DIAPHRAGM KIT3 2 GASKET–BOOST

4 2 DIAPHRAGM5 1 GASKET–PULSE6 1 SPRING7 1 CAP8 1 RETAINER9 1 SPRING

10 1 CAP11 1 BASE12 1 PLATE13 1 ELBOW (45 DEGREE)14 1 ELBOW (90 DEGREE)15 2 SCREW–FUEL PUMP (M5 x 40) 60 6.816 2 SCREW–PUMP TO CRANKCASE (M6 x 50) 60 6.8

17 1 ELBOW18 3 O–RING (WB#326–028)19 1 GASKET


90-889785 APRIL 2003 A-3

Fuel Pump Description/Operation

The fuel pump is a crankcase-pressure-operated, diaphragm type pump. Crankcase pul-sating pressure (created by the up and down movement of piston) is transferred to fuelpump by way of a passage (hole) between crankcase and fuel pump.

When piston is in an upward motion, a vacuum is created in the crankcase, thus pullingin on the fuel pump diaphragm. The inlet check valve (in fuel pump) is opened and fuel(from fuel tank) is drawn into fuel pump.

Downward motion of the piston forces the mixture out of the crankcase into the cylinder.This motion also forces out on the fuel pump diaphragm, which, in turn, closes the inletcheck valve (to keep fuel from returning to fuel tank) and opens the outlet check valve,thus forcing fuel to the VST.

Checking for Restricted Fuel Flow Caused by Anti-SiphonValves

While anti-siphon valves may be helpful from a safety stand-point, they clog with debris,they may be too small, or they may have too heavy a spring. Summarizing, the pressuredrop across these valves can, and often does, create operational problems and/or powerhead damage by restricting fuel to the fuel pump and VST. Some symptoms of restricted(lean) fuel flow, which could be caused by use of an anti-siphon valve, are:

1 - Loss of fuel pump pressure 2 - Loss of power 3 - High speed surging 4 - Preignition/detonation (piston dome erosion)5 - Outboard cuts out or hesitates upon acceleration 6 - Outboard runs rough7 - Outboard quits and cannot be restarted 8 - Outboard will not start 9 - Vapor lock

Since any type of anti-siphon device must be located between the outboard fuel inlet andfuel tank outlet, a simple method of checking [if such a device (or bad fuel) is a problemsource] is to operate the outboard with a separate fuel supply which is known to be good,such as a remote fuel tank.

If, after using a separate fuel supply, it is found that the anti-siphon valve is the cause ofthe problem, there are 2 solutions to the problem; either 1) replace the anti-siphon valvewith one that has lighter spring tension or 2) replace it with a solenoid-operated fuel shutoff valve.


Page 3A-4 90-889785 APRIL 2003

Checking Fuel Pump Lift (Vacuum)The square fuel pump is designed to lift fuel (vertically) about 1524 mm (60 in.) if thereare no other restrictions in the system using a fuel hose that is 7.9 mm (5/16 in.) minimumdiameter. As restrictions are added, such as filters, fittings, valves etc., the amount of fuelpump lift decreases.

Fuel pump vacuum and air bubbles in the fuel supply can be checked with a vacuumgauge, a t-fitting and a clear piece of fuel hose. Connect the clear hose between the inletfitting on the pulse driven fuel pump and the vacuum gauge t-fitting. Keep the t-fitting andthe gauge as close as possible to the pump for the most accurate readings. Connect thefuel line from the fuel tank to the remaining connection on the t-fitting.

ob57771

a

b

c

a - Clear hoseb - T-fittingc - Vacuum gauge

Vacuum Test TroubleshootingThis test is normally performed at an idle speed. As engine rpm increases, there will bea slight increase in vacuum. The increase should not exceed specification

Normal Reading Below 2.5 in. of mercury

Reading above 2.5 in. of mercury Restriction within the fuel system – • Restricted anti-siphon valve• Restriction within the primer bulb• Kinked or collapsed fuel hose• Plugged water separating fuel filter (in the

boat)• Restriction in fuel line thru-hull fitting• Restriction in fuel tank switching valves• Plugged fuel tank pick-up screen


90-889785 APRIL 2003 Page 3A-5

Testing Fuel PumpInstall clear fuel hose between fuel pump and VST. Run engine, and inspect fuel passingthru hose for air bubbles.

Problem: Air Bubbles in Fuel LineLow fuel in tank. Fill tank with fuel.

Loose fuel line connection. Check and tighten all connectors.

Fuel pump fitting loose. Tighten fitting.

A hole or cut in fuel line. Check condition of all fuel lines and replace.

Fuel pump anchor screw loose. Tighten all screws evenly and securely.

Fuel pump filter cover anchor screw loose. Tighten screws securely.

Fuel pump filter gasket worn out. Replace gasket.

Fuel pump gasket worn out. Rebuild fuel pump.

Fuel vaporizing Fuel with high reed vapor pressure (winter gradefuel) may vaporize (form bubbles) when used inhot/warm weather. Use fuel with a lower reed va-por pressure (summer grade fuel).

Problem: Lack of Fuel Pump PressureAn anti-siphon valve. See Checking for Restricted Fuel Flow preced-

ing.

Air in fuel line. See Air Bubbles in Fuel Line , above.

A dirty or clogged fuel filter. Clean or replace fuel filter.

The fuel pickup in fuel tank is clogged or dirty. Clean or replace pickup.

Worn out fuel pump diaphragm. Rebuild fuel pump.

Worn out check valve in fuel pump. Rebuild fuel pump.

A leaky check valve gasket. Rebuild fuel pump.

Pulse hole plugged. Remove fuel pump and clean out holes.

Hole in pulse hose. Replace pulse hose.

Loose pulse hose. Tighten connection.

Fuel hose internal diameter too small. Use 5/16 I.D. fuel hose.

Primer bulb check valve not opening. Replace primer bulb.

Excessive fuel lift required. Fuel lift exceeds 2.5 in. of vacuum (mercury).


Page 3A-6 90-889785 APRIL 2003

Fuel Pump Removal/Disassembly

IMPORTANT: Fuel pump diaphragm and gaskets should not be re-used once fuelpump is disassembled.

1. Disconnect fuel hose from tank to fuel pump.

2. Disconnect pulse hose.

3. Remove 2 mounting screws.

4. Remove fuel pump.

dc

a

b

ob00884

b

a - Fuel hoseb - Pulse hoses

c - Mounting screwsd - Fuel pump

5. Disassemble fuel pump.


90-889785 APRIL 2003 Page 3A-7

Cleaning/Inspection1. Clean fuel pump housing, check valves, pulse chamber and pump base in solvent and

dry all but check valves with compressed air.

2. Inspect each check valve for splits, chips and for proper sealing against pump hous-ing.

3. Inspect boost springs for weakness or breakage.

4. Inspect fuel pump housing, pulse chamber and base for cracks or rough gasket sur-face and replace if any are found.

5. Inspect fitting on fuel pump housing for loosening or any signs of fuel or air leaks. Re-place or tighten fitting if a leak is found.

Reassembly/lnstallationASSEMBLY

NOTE: The new repair kits contain check valves made of a plastic material, imperviousto damage from additives. When repairing the fuel pump discard old rubber and smallplastic check valve disks, and install one new plastic disk under each retainer. Cautionmust be taken not to push the check valve retainer to tightly against the check valve, thismay cause valve to deform.

b

ob57861

a

CORRECT INCORRECT

a - Check valve retainerb - Check valve (plastic)

1. Insert retainer through plastic check valve.

a

ob23601

a

b

a - Retainerb - Plastic check valve


Page 3A-8 90-889785 APRIL 2003

2. Install check valves and retainers into fuel pump body.

3. With retainer installed in pump body, break retainer rod from retainer by bending side-ways.

a

b

ob23601

a

b

a - Rodb - Retainer cap

4. Reinstall rod into retainer cap and, use a small hammer and punch to tap rod downinto retainer until flush with top of retainer.

a

b

ob23601

a

b

a - Rodb - Retainer cap


90-889785 APRIL 2003 Page 3A-9

5. Place boost spring into pump body and place cap onto boost spring.

c

a

b

a

b

c

ob50161

a - Boost springb - Pump bodyc - Cap

6. Assemble remainder of components as shown and install retaining screws throughto align.

a


Page 3A-10 90-889785 APRIL 2003

7. Install pump onto engine. Torque attaching screws to specification.

8. Install hoses onto proper fittings and secure with cable ties.

9. Run engine and check for leaks.

dc

a

b

ob00884

b

a - Fuel hoseb - Pulse hoses

c - Mounting screwsd - Fuel pump

REFTORQUE


a 2 SCREWS 60 6.8

3B

DIRECT FUEL INJECTION

90-889785 APRIL 2003 Page 3B-1

FUEL SYSTEMSection 3B – Direct Fuel Injection

Table of Contents

Specifications 3B-2. . . . . . . . . . . . . . . . . . . . . . . . . . . Special Tools 3B-3. . . . . . . . . . . . . . . . . . . . . . . . . . . Throttle Body 3B-6. . . . . . . . . . . . . . . . . . . . . . . . . . . Reed Block 3B-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel System 3B-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . Vapor Separator Components 3B-12. . . . . . . . . . . . . Fuel Rail Components 3B-14. . . . . . . . . . . . . . . . . . . Vapor Separator/Fuel Rail Mounting 3B-16. . . . . . . Air Hoses 3B-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air Compressor Components 3B-20. . . . . . . . . . . . . DFI Operation 3B-22. . . . . . . . . . . . . . . . . . . . . . . . . .

Air Induction Through Crankcase 3B-22. . . . . . . Air Compressor System 3B-22. . . . . . . . . . . . . . . Fuel 3B-22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil 3B-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electrical 3B-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . Operation 3B-23. . . . . . . . . . . . . . . . . . . . . . . . . . .

Testing Electric Fuel Pump Pressure Output 3B-24Low Pressure Electric Fuel Pump 3B-24. . . . . . . High Pressure Electric Fuel Pump 3B-25. . . . . .

Fuel Management Assembly Removal 3B-26. . . . . Air Temperature Sensor Removal 3B-31. . . . . . Air Temperature Sensor Installation 3B-31. . . . . MAP Sensor Removal 3B-32. . . . . . . . . . . . . . . . MAP Sensor Installation 3B-32. . . . . . . . . . . . . . .

Throttle Plate Assembly Removal 3B-33. . . . . . . Throttle Plate Assembly Installation 3B-33. . . . . Reed Block Assembly Removal 3B-34. . . . . . . . Reed Block Assembly Installation 3B-34. . . . . . . Vapor Separator Tank Disassembly 3B-37. . . . . Fuel Flow Director Components 3B-40. . . . . . . . Vapor Separator Tank Reassembly 3B-41. . . . . Air Plenum Installation 3B-46. . . . . . . . . . . . . . . . Vapor Separator Installation 3B-46. . . . . . . . . . . Fuel Rail Removal 3B-48. . . . . . . . . . . . . . . . . . . . Fuel Pressure Regulator 3B-54. . . . . . . . . . . . . . Air Pressure Regulator 3B-59. . . . . . . . . . . . . . . . Air Regulator Troubleshooting 3B-60. . . . . . . . . . Fuel Rail Cleaning 3B-64. . . . . . . . . . . . . . . . . . . . Direct Injector Removal 3B-64. . . . . . . . . . . . . . . Direct Injector Leak Test 3B-67. . . . . . . . . . . . . . . Fuel Rail and Direct Injector Installation 3B-68. Air Compressor 3B-69. . . . . . . . . . . . . . . . . . . . . .

Notes: 3B-73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air Compressor Disassembly/Reassembly 3B-74Air Compressor End Cap/CrankshaftRemoval and Reassembly 3B-76. . . . . . . . . . . . . Air Compressor Flow Diagram 3B-81. . . . . . . . . Air Compressor Pressure Test 3B-82. . . . . . . . . Fuel Injector Test 3B-84. . . . . . . . . . . . . . . . . . . . .


Page 3B-2 90-889785 APRIL 2003

Specifications

Fuel System Specifications

Fuel Pressure 744.6 ± 13.8 kPa (108 ± 2 psi)

Air Pressure 648.1 ± 13.8 kPa (94 ± 2 psi)

Fuel/Air Differential 96.5 kPa ± 6.9 kPa (14.0 ± 1.0 psi)

High and Low Pressure Fuel Pump AmperageDraw

10-14 Amps

Low Pressure Electric Fuel Pump Output 137.9 kPa - 206.8 kPa (20-30 psi)

Fuel Injector Ohm Resistance 1.8 ± 0.1ΩDirect Injector Ohm Resistance 1.3 ± 0.3Ω

Air Compressor SpecificationsAir Compressor Type

Compressor Output

Reciprocating Piston(1.14 to 1 ratio with engine RPM)

@ Idle – 655 kPa (95 psi)

Cylinder Block Displacement 60 cc (3.66 cu. in.)

Cylinder Bore Diameter (Standard)Taper/Out of Round/Wear Maxi-mumBore Type

52.0 mm (2.0472 in.)

0.025 mm (0.001 in.)Cast Iron

Stroke Length 27.9 mm (1.100 in.)

Piston Piston Type Aluminum

Piston Diameter

Dimen-sion “A”at RightAngle(90°) toPiston Pin

0.300 in.

51.95 ± 0.010 mm(2.0453 ± .0004 in.)

Piston Ring End GapTop Ring

Middle Ring

Bottom Ring

0.15 - 0.30 mm(0.0059 - 0.0118 in.)

0.15 - 0.30 mm(0.0059 - 0.0118 in.)

0.10 - 0.35 mm(0.0039 - 0.014 in.)

Reeds Reed Stand Open 0.25 mm (0.010 in.)


90-889785 APRIL 2003 Page 3B-3

Special Tools

Duel Fuel/Air Pressure Gauge 1103.2 kPa (160 psi) 91-852087A1/A2/A3

Adaptors to convert pressure gauge 91-852087A1/A2

to an A3

91-803804A2

a b c d e

NOTE: 2 Adaptors 91-803804A2 are required to convert a pressure gauge set.

a - 1/2 in. to 1/4 in. Adapter – if requiredb - Female quick disconnectc - Male quick disconnectd - Screw on Schradere - O-ring 25-803803

Seal/Teflon Ring Installation Tool 91-851980--3

56015


Page 3B-4 90-889785 APRIL 2003

Seal/Teflon Ring Sizing Tool 91-851980-2

ob56014

DMT 2000 Digital Tachometer Multi-meter 91-854009T1

Direct Injector Removal Tool 91-883521


90-889785 APRIL 2003 Page 3B-5

Clamp Tool Kit 91-803146A2

ob57316

a

a - Clamp tool 91-803146T

Gearcase Leakage Tester FT-8950

ob57714

Regulator Installation Tool 91-889431

ob59361


Page 3B-6 90-889785 APRIL 2003

Throttle Body


90-889785 APRIL 2003 Page 3B-7

Throttle Body (Continued)

REFTORQUE


1 1 THROTTLE BODY ASSEMBLY

2 1 PLATE3 4 SCREW 100 11.34 1 GROMMET5 1 GROMMET6 1 CLAMP7 1 SCREW

8 1 WASHER9 1 WASHER10 1 BUSHING11 1 THROTTLE LEVER KIT12 1 THROTTLE ROLLER ASSEMBLY13 1 LOCKWASHER14 1 WASHER

15 1 WASHER16 1 SCREW17 1 ROLLER18 1 BRACKET19 3 SCREW (M6 x 16) 105 11.920 2 CABLE21 1 CAM

22 1 SPACER23 1 WASHER24 1 SCREW (M6x 40) 95 10.725 1 COUPLER26 1 TPI27 3 SCREW 24 2.728 1 CLAMP – Oetiker

29 2 CONDUIT [33 cm (13 in.)]


Page 3B-8 90-889785 APRIL 2003

Reed Block

14

25

TubeRef. # Description Mercury Part Num-

berQuicksilver Part

Number

142 Cycle Premium Out-

board Oil92-802813A1 92-802813Q1

25 Liquid Neoprene 92-25711-3 92-25711-3


90-889785 APRIL 2003 Page 3B-9

Reed Block (Continued)

REFTORQUE


1 1 SHIFT RAIL

2 2 TAB WASHER3 2 SCREW (M8 x 25) 18 24.44 1 SLIDE5 1 NUT6 1 WASHER

7 1 NUT Drive tight; but jointmust be free to pivot

8 1 GASKET9 1 LOWER END CAP ASSEMBLY10 1 CHECK VALVE11 1 OIL SEAL12 1 O-RING

13 3 SCREW (M10 x 25)14 1 REED ADAPTOR PLATE15 1 GASKET16 1 FITTING17 1 COVER18 1 GASKET

19 9 SCREW (M8 x 45) 18 24.420 15 SCREW (M8 x 35) 18 24.421 3 REED BLOCK22 3 GASKET23 6 SCREW (M6 x 20) 90 10.224 1 MAP SENSOR25 1 BRACKET

26 1 SCREW (M6 x 16) 90 10.227 1 TEMPERATURE SENSOR 13 1.428 1 O-RING29 1 NEGATIVE BATTERY CABLE30 2 SCREW (M8 x 14) 18 24.431 4 WASHER32 1 CLAMP


Page 3B-10 90-889785 APRIL 2003

Fuel System

NOTE: A = To Crankcase

NOTE: B = To Vent Fitting


90-889785 APRIL 2003 Page 3B-11

Fuel System (Continued)

REFTORQUE


1 1 HOSE – VENT

2 AR CABLE TIE (8 in.)3 1 HOSE ASSEMBLY4 1 HOSE ASSEMBLY5 1 SCHRADER VALVE6 1 O–RING7 1 CLIP

8 1 SCREW (M6 x 12) 90 10.29 1 TUBING (10-1/2 in.)10 1 FITTING11 1 TUBING (28 in.)12 1 TUBING (4-1/2 in.)13 1 CLAMP (15.3)14 1 HOSE

15 1 SEAL


Page 3B-12 90-889785 APRIL 2003

Vapor Separator Components

A


90-889785 APRIL 2003 Page 3B-13

Vapor Separator Components (Continued)

REFTORQUE

REF.NO. QTY. DESCRIPTION lb. in. lb. ft. N·m

1 1 COVER KIT2 1 SEAT3 1 BAFFLE PLATE4 2 SCREW 22 2.55 1 GASKET6 1 FITTING 75 8.57 1 O-RING

8 1 FITTING 50 5.59 1 PLUG 45 510 1 FUEL FILTER11 1 FLOAT KIT12 1 FLOAT PIN13 1 FUEL PUMP–HIGH PRESSURE

14 1 SLEEVE15 1 O-RING16 1 SEAL17 1 RETAINER18 11 SCREW 40 4.519 1 BOOST PUMP20 1 GROMMET

21 1 O-RING22 1 SEAL23 1 BOWL KIT24 1 WIRE25 1 CHECK VALVE26 2 FITTING27 1 INLET VALVE KIT

28 2 DRAIN SCREW 15 1.729 2 O-RING30 1 WATER SENSOR31 1 ELBOW (90 DEGREE) Note32 2 O-RING33 1 INSERT

NOTE: Install elbow fitting in to VST 5 turns minimum – 7 turns maximum.

A – Torque retainer screws to 2.5 Nm (22 lb. in.)


Page 3B-14 90-889785 APRIL 2003

Fuel Rail Components


90-889785 APRIL 2003 Page 3B-15

Fuel Rail Components (Continued)

REFTORQUE

REF.NO. QTY. DESCRIPTION lb. in. lb. ft. N·m

1 1 FUEL RAIL ASSEMBLY2 1 FUEL PLUG3 2 SEAL4 2 CLAMP5 9 SCREW (M5 x 10) 70 86 1 O-RING7 1 FITTING

8 1 BRACKET9 3 INJECTOR10 1 O-RING KIT11 1 O-RING KIT12 3 RETAINER13 2 VALVE KIT - SCHRADER

14 2 CAP15 1 O-RING KIT16 2 CLAMP17 1 ELBOW18 1 AIR PLUG19 1 FITTING20 1 O-RING

21 2 CLAMP22 1 O-RING KIT23 1 O-RING (16 per kit)


Page 3B-16 90-889785 APRIL 2003

Vapor Separator/Fuel Rail Mounting


berQuicksilver Part

Number

1104 Stroke 10W30 Out-

board Oil92-802833A1 92-802833Q1


90-889785 APRIL 2003 Page 3B-17

Vapor Separator/Fuel Rail Mounting (Continued)

REFTORQUE

REF.NO. QTY. DESCRIPTION lb-in lb-ft Nm

1 2 STUD (M10 x 91) Drive Tight

2 2 NUT 33 44.73 3 AIR INJECTOR4 3 CUPPED WASHER5 2 SPACER6 3 GROMMET7 3 WASHER

8 2 SCREW (M8 x 60) 18 24.49 1 SCREW (M8 x 35) 18 24.410 1 BUSHING


Page 3B-18 90-889785 APRIL 2003

Air Hoses


90-889785 APRIL 2003 Page 3B-19

Air Hoses (Continued)

REFTORQUE

REF.NO. QTY. DESCRIPTION lb-in lb-ft Nm

1 1 TUBING [20.3 cm (8 in.)]

2 2 CLAMP (15.3)3 1 HOSE4 1 HOSE ASSEMBLY5 2 CABLE TIE [20.3 cm (8 in.)]6 1 AIR MUFFLER7 1 HOSE [11.4 cm (4-1/2 in.)]


Page 3B-20 90-889785 APRIL 2003

Air Compressor Components

7

7

14

14

9

9

9

14

14

Tube Ref.#

Description Mercury Part Number Quicksilver Part Number

7Loctite 271

Threadlocker92-809819 92-809819

9Loctite 567 PST Pipe

Sealant92-809822 92-809822

142 Cycle Premium Outboard

Oil92-802813A1 92-802813Q1


90-889785 APRIL 2003 Page 3B-21

Air Compressor Components (Continued)

REFTORQUE


1 1 AIR COMPRESSOR2 1 END CAP3 1 O–RING4 1 CONNECTING ROD5 1 PISTON ASSEMBLY (WITH RINGS)6 2 LOCK RING7 1 REED PLATE ASSEMBLY

8 1 GASKET9 1 GASKET10 1 COMPRESSOR HEAD11 1 ELBOW (45 Degree)12 4 SCREW (M8 x 1.25) 20 27.113 2 ELBOW

14 1 FITTING 25 33.915 1 O–RING16 1 TEMPERATURE SENSOR 13 1.417 1 O–RING18 3 CHECK VALVE 58 6.619 1 PIN 45 5.120 1 ELBOW

21 5 CABLE TIE22 1 HOSE23 1 CHECK VALVE24 1 SCREW (M6 x 20) 100 11.325 1 PULLEY26 3 SCREW (M6 x 12) 100 11.327 1 TENSIONER ARM

28 1 PULLEY29 1 SCREW (M10 x 25) 18.8 25.430 1 BEARING31 1 BUSHING32 2 TUBING [45.7 cm (18 in.)]33 1 SPRING34 1 SCREW (M10 x 45) 16.7 22.6

35 1 WASHER36 1 TUBING [55.8 cm (22 in.)]37 6 CABLE TIE [20.3 cm (8 in.)]38 3 SCREW (M8 x 90) 18 24.4


Page 3B-22 90-889785 APRIL 2003

DFI Operation

Air Induction Through CrankcaseCombustion air enters the cowl through holes located in the top aft end of the cowl. Thecowl liner directs this air to the bottom of the powerhead. This limits the exposure of saltair to the components inside the engine cowl.

Once inside the cowl the air enters the plenum through the throttle shutter which is locatedin the plenum assembly. The air then continues through the reed valves and into thecrankcase. The throttle shutter is actuated by the throttle shaft. Mounted on a separateshaft is a throttle position sensor (TPS). This sensor tells the propulsion control unit (PCM)the position of the throttle.

Air Compressor System

Air from inside the engine cowl is drawn into the compressor through an air filter in theair attenuator. This attenuator acts like a muffler to quiet compressor noise and containsa filter to prevent the ingestion of debris into the compressor. The compressor is drivenby a belt from a pulley mounted on the flywheel and is automatically self-adjusted usinga single idler pulley. This air compressor is a single cylinder unit containing a connectingrod, piston, rings, bearings, reed valves, and a crankshaft. The compressor is watercooled to lower the temperature of the air charge and is lubricated by oil from the engineoil pump assembly. As the compressor piston moves downward inside the cylinder, airis pulled through the filter, reed valves and into the cylinder. After the compressor pistonchanges direction, the intake reeds close and the exhaust reeds open allowing com-pressed air into the hose leading to the air/fuel rails.

The air/fuel rails contain two passages; one for fuel, the second for air. The air passageis common between all the cylinders included in the rail. A hose connects the rail air pas-sage to the air compressor. An air pressure regulator will limit the amount of pressure de-veloped inside the air passages to approximately 96.5 kPa (14 psi) below the pressureof the fuel inside the fuel passages [i.e. 648.1 kPa (94 psi) air vs 744.6 kPa (108 psi) fuel].Air exiting the pressure regulator is discharged through a muffler into the lower cowling.

FuelFuel for the engine is stored in a typical fuel tank. A primer bulb is installed into the fuelline to allow priming of the fuel system. A vapor separator mounted diaphragm fuel pumpdraws fuel through the fuel line, primer bulb and fuel pump assembly. The pump thenpushes the fuel through a water separating fuel filter. This filter removes any contaminatesand water before the fuel reaches the vapor separator. Fuel vapors are vented throughthe bottom cowling into the atmosphere. The electric fuel pump is capable of developingfuel pressures in excess of 744.6 kPa (108 psi). Fuel inside the rail must remain pressur-ized at exactly 96.5 kPa (14 psi) over the air rail pressure or the PCM (map) calibrationswill be incorrect. Fuel from the vapor separator is supplied to the top of the fuel rail. Fuelis stored inside the rail until an injector opens. A fuel pressure regulator controls pressurein the fuel rail, and allows excess fuel to return into the vapor separator. The fuel regulatornot only regulates fuel pressure but also regulates it at 96.5 kPa (14 psi) higher than what-ever the air rail pressure is. The fuel regulator diaphragm is held closed with a spring thatrequires 96.5 kPa (14 psi) to force the diaphragm off the diaphragm seat. The back sideof the diaphragm is exposed to air rail pressure. As the air rail pressure increases, the fuelpressure needed to open the regulator will equally increase. Example: If there is 344.7kPa (50 psi) of air pressure on the air rail side of the diaphragm, 441.3 kPa (64 psi) of fuelpressure will be required to open the regulator. The fuel rail is water cooled.


90-889785 APRIL 2003 Page 3B-23

OilOil in this engine is not mixed with the fuel before entering the combustion chamber. Oil is storedinside an engine mounted reservoir.

A remote oil tank is available as an option. Crankcase pressure will force oil from the remoteoil tank into the oil reservoir on the front of the powerhead.

Oil will flow from the oil reservoir into the oil pump. The oil pump is a solenoid design. It is acti-vated by the PCM and includes 7 pistons with corresponding discharge ports. The oil pumpis mounted on the electrical plate. Each cylinder is lubricated by one of the discharge ports. Theoil is discharged into the crankcase. The seventh passage connects to the hose that leads tothe air compressor for lubrication. Excess oil from the compressor returns into the cylinderbores.

The PCM will change the discharge rate of the oil pump, depending upon engine demand. ThePCM will also pulse the pump on initial start up to fill the oil passages eliminating the need tobleed the oil system. The PCM provides additional oil for break-in, as determined by its internalclock. The oil ratio varies with engine RPM and load.

ElectricalThe electrical system consists of the PCM, crank position sensor (flywheel speed & crankshaftposition), throttle position sensor (TPS), MAP sensor, engine temperature sensor, ignition coilsand injectors (fuel & direct). The engine requires a battery to start (i.e. the ignition and injectionwill not occur if the battery is dead). The system will run off of the alternator.

OperationThe operation of the system happens in milliseconds (ms). Exact timing is critical for engineperformance. As the crankshaft rotates, air is drawn into the crankcase through the throttleshutter, into the plenum and through the reed valves. As the piston nears bottom dead center,air from the crankcase is forced through the transfer system into the cylinder. As the crankshaftcontinues to rotate the exhaust and intake ports close. With these ports closed, fuel can beinjected into the cylinder. The PCM will receive a signal from the throttle position sensor (TPS),engine temperature sensor (TS) and the crank position sensor (flywheel speed and positionsensor). With this information, the PCM refers to the fuel calibration (maps) to determine whento activate (open and close) the injectors and fire the ignition coils. With the piston in the correctposition, the PCM opens the fuel injector, 744.6 kPa (108 psi) fuel is discharged into a ma-chined cavity inside the air chamber of the air/fuel rail. This mixes the fuel with the air charge.Next the direct injector will open, discharging the air/fuel mixture into the combustion chamber.The direct injector directs the mixture at the bowl located in top of the piston. The piston’s bowldirects the air/fuel mixture into the center of the combustion chamber. This air fuel mixture isthen ignited by the spark plug.

Compressor Notes: To aid in starting when the air rail pressure is low and before the compres-sor has time to build pressure, some direct injectors are held open by the PCM. This allowsthe compression from inside the cylinders to pressurize the air rail faster (1 or 2 strokes, or 60°

of crankshaft rotation).

Idle Notes: Idle quality is controlled by fuel volume and fuel timing. The throttle shutter will beopen at idle speed. The shift switch is mounted on the exhaust adaptor plate and is activatedby a cam/notch in the upper shift shaft. The switch has a closed circuit when the engine is ingear (forward or reverse) and an open circuit when the engine is in neutral. The switch is moni-tored by the PCM. The PCM will change fueling, timing and RPM limit according to whetherthe engine is in gear or in neutral.

The TPS signals the PCM to change the fuel and spark without movement of the throttleshutters. The throttle cam is manufactured to allow the TPS sensor shaft to move beforeopening the throttle shutter.


Page 3B-24 90-889785 APRIL 2003

Testing Electric Fuel Pump Pressure Output

Low Pressure Electric Fuel Pump1. Connect Dual Fuel/Air Pressure Gauge [91-852087A1/A2/A3] to Schrader valve on

VST. Gauge should indicate 137.9 – 206.8 kPa (20 – 30 psi).

ob57416

a

ob59586

a - Low pressure electric fuel pump Schrader valve


90-889785 APRIL 2003 Page 3B-25

High Pressure Electric Fuel Pump1. Install Pressure Gauge Assembly 91-852087A1/A2/A3 to fuel rail pressure test valve.

NOTE: After 15 seconds of cranking engine with starter motor, fuel pressure gaugeshould indicate 744.6 ± 13.8 kPa (108 ± 2 psi).

ob59607

91-852087A1/A2/A3

a

b

a - Fuel pressure gauge [should indicate 744.6 ± 13.8 kPa (108 ± 2 psi)]b - Fuel pressure test valve (bottom of fuel rail)


Page 3B-26 90-889785 APRIL 2003

Fuel Management Assembly Removal

CAUTIONFuel system must be bled off prior to removal of fuel system components.

WARNINGDrain fuel from vapor separator tank (VST) into a suitable container. Even thoughVST has been drained, fuel may still remain in fuel rails and hoses. Normal pre-cautionary procedures should be adhered to while working with the fuel system.Avoid sparks, smoking and open flame while in the presence of liquid fuel or fuelvapors.

NOTE: Use Fuel/Air Pressure Gauge 91-16850--1 or 91-852087A1/A2/A3 to de-pressur-ize air hose first and then fuel hose.

1. De-pressurize fuel system.

ob59594

a b

c

d

e

a - Air pressure gaugeb - Fuel pressure gaugec - Air pressure port

d - Fuel pressure port (Design 1)e - Fuel pressure port (Design 2)


90-889785 APRIL 2003 Page 3B-27

2. Cut cable tie securing VST vent hose.

3. Place suitable container underneath vapor separator drain fittings. Turn respectiverelease screw to allow fuel to drain from fitting. Use rubber hose connecting drain fit-tings to direct fuel into suitable container. After fuel is drained from VST, close off eachrelease screw and reattach hose to each drain fitting.

4. Disconnect water separator sensor connector.

ob00526

bb

a

cd

e

a - Cable tiesb - Release screwsc - Water separator sensor lead

d - Rubber hosee - Drain fittings

5. Disconnect electric fuel pump harness connector.

ob59610

a

a - Electric fuel pump connector


Page 3B-28 90-889785 APRIL 2003

6. Remove the inlet fuel hose from the pulse fuel pump.

7. Remove pulse fuel pump vacuum hoses (2 each).

8. Remove the fuel outlet hose and fuel return hose on vapor separator tank (VST).

9. Remove 3 mounting bolts and remove separator.

ob00883

a

b

c

de

e

a - Fuel inlet hose to pulsepump

b - Fuel outlet hose (dis-connect at fuel rail)

c - Fuel return hosed - Mounting boltse - Pulse pump vacuum

hoses


90-889785 APRIL 2003 Page 3B-29

10. Remove throttle arm screw and throttle cable platform screw.

11. Disconnect MAP sensor, air temperature sensor and throttle position sensor harnessconnectors.

ob00694

c

d

e

ob00712

a

b

a - Throttle arm screwb - Throttle cable platform screwc - MAP sensor connector

d - Air temperature sensor connectore - Throttle position sensor connector


Page 3B-30 90-889785 APRIL 2003

12. Remove 9 screws securing air plenum and remove plenum/throttle body assembly.

ob00707

a

a

a

a

aa

a

a

a

a - Screws


90-889785 APRIL 2003 Page 3B-31

Air Temperature Sensor Removal1. Disconnect sensor harness.

2. Unscrew sensor from air plenum.

ob59574

a

b

a - Air temperature sensor harness connectorb - Air temperature sensor

Air Temperature Sensor Installation1. Screw sensor into air plenum.

2. Reconnect sensor harness.

REFTORQUE


b 1 TEMPERATURE SENSOR 13 1.4


Page 3B-32 90-889785 APRIL 2003

MAP Sensor Removal1. Disconnect wiring harness.

2. Remove screw securing MAP sensor retainer and remove sensor.

a

ob59575

b

c

a - MAP sensorb - Screwc - Harness connector

MAP Sensor Installation1. Install sensor into air plenum.

2. Reconnect sensor harness connector.

REFTORQUE


b 1 SCREW (M6 x 16) 90 10.2


90-889785 APRIL 2003 Page 3B-33

Throttle Plate Assembly RemovalNOTE: The throttle plate assembly is calibrated and preset for proper running character-istics and emissions at the factory. Other than complete assembly removal from the airplenum, no further disassembly should be made.

1. Remove 4 bolts securing throttle plate assembly to air plenum and remove assembly.

ob00356

a

b

a - Screws (4) b - Throttle plate assembly

Throttle Plate Assembly Installation1. Secure throttle plate assembly to air plenum with 4 screws.

REFTORQUE


a 4 SCREW 100 11.3


Page 3B-34 90-889785 APRIL 2003

Reed Block Assembly Removal1. Remove 9 screws securing cover to reed block adaptor plate.

2. Remove 15 screws securing reed block adaptor plate to crankcase cover.

3. Remove 2 screws securing each reed block to adaptor plate.

a

b

c

e

d

f

g

a - Screws (9 each) (M8 x 45)b - Coverc - Adaptor Plated - Screws (6 each) (M6 x 20)e - Crankcase Coverf - Reed Block (3 each)g - Screws (15 each) (M8 x 35)

Reed Block Assembly InstallationNOTE: Replace all gaskets for lasting repair.

1. Secure each reed block with 2 screws to adaptor plate.

REFTORQUE


d 6 SCREW (M6 x 20) 90 10.2


90-889785 APRIL 2003 Page 3B-35

2. Secure adaptor plate to crankcase cover with 15 screws. Torque screws in followingsequence.

ob00792

a

REFTORQUE


a 15 SCREW (M8 x 35) 18 24.4


Page 3B-36 90-889785 APRIL 2003

3. Reinstall cover with 9 screws. Torque screws in following sequence.

ob00820

a

1

2

3

4

5 6

78

9

REFTORQUE


a 9 SCREW (M8 x 45) 18 24.4


90-889785 APRIL 2003 Page 3B-37

Vapor Separator Tank Disassembly1. Remove 2 screws securing pulse fuel pump to VST and remove pump. Refer to Sec-

tion 3A for disassembly, inspection and reassembly of pulse fuel pump.

ob59376

b

a

a - Pulse fuel pump b - Screws

2. Remove fuel/water separator filter from VST. Inspect filter O-rings for cuts or abrai-sions. Replace O-rings as required. Inspect filter element for debris. Remove debrisor replace element as required.

ob59372

b

ob59375

a

c

a - Fuel/water separatorfilter

b - O-ringsc - Filter element


Page 3B-38 90-889785 APRIL 2003

3. Remove water sensor from VST and inspect for debris or corrosion. Clean or replaceas required. Inspect sensor O-ring for cuts or abrasions. Replace as required.

ob59370

b

ob59371

a

a - Water sensorb - O-ring

4. Remove 9 screws securing VST cover and remove cover. Inspect cover sealing ringfor cuts or abraisions. Replace as required.

ob59378

ob59374

a

b

a - Screws (9)b - Sealing ring


90-889785 APRIL 2003 Page 3B-39

5. Loosen screw securing float assembly and remove float. Inspect float for deteriorationor fuel retention. Replace float as required. Inspect float needle and seat for wear, de-bris or corrosion. Replace needle and seat as required.

ob59342a

b

c

a - Floatb - Screw

c - Float needle

6. Remove 2 screws securing low pressure fuel pump.

7. Remove low and high pressure pumps from VST. Disconnect electrical connectorsfrom each pump. Inspect O-rings on each pump and on harness for cuts or abraisions.Replace as required.

b ca

ob59377

ee

e

dd

b

c

ob59378

a - Screwsb - Low pressure pumpc - High pressure pump

d - Electrical connectorse - O-rings


Page 3B-40 90-889785 APRIL 2003

Fuel Flow Director ComponentsCOMPONENTS

ob00815

a

b

c

a - Fuel director insertb - Sealc - Seal

ASSEMBLY VIEW

ob00816

a

b

ce

d

a - High pressure fuel pumpb - Sealc - Fuel director insertd - Check valvee - Seal (install on fitting)


90-889785 APRIL 2003 Page 3B-41

Vapor Separator Tank Reassembly1. Apply light oil to fuel pump elbow O-rings to aid installation into vapor separator.

2. Align gasket between fuel pump and VST. Secure fuel pump to VST with 2 screws.

3. Retorque assembly screws.

ob59376

a

b

c

c

d

e

a - Elbowb - Fuel pumpc - Assembly screws

d - Attaching screwse - Gasket (hidden)

REFTORQUE

REF.NO. QTY. DESCRIPTION lb-in lb-ft Nm.c/d 4 SCREW 60 6.8

4. Apply light oil to water sensor O-ring and reinstall sensor in VST.

ob59370

b

ob59371

a

a - Water sensorb - O-ring


Page 3B-42 90-889785 APRIL 2003

NOTE: If the fuel pump harness must be replaced, the new harness must be routedthrough the VST casting before installing the RED and BLACK wire pins into the harnessconnector. To ensure correct electrical polarity, the RED wire pin must be installed intothe (A) pin receptacle and the BLACK wire pin must be installed into the (B) pin receptacle.After both pins are installed and locked into the connector, slide the pin retainer over theharness and lock in place on the connector.

ob59373

e

f

a

bc d

a - (A) pin receptacleb - Pin retainerc - RED wired - BLACK wiree - (B) pin receptaclef - Connector


90-889785 APRIL 2003 Page 3B-43

5. Apply light oil to electric fuel pump O-rings and pump harness O-rings.

6. Attach electrical harnesses to each fuel pump. Secure high pressure pump harnessto pump with cable tie.

ob59377

a a

a

b

c

a - O-ringsb - Electrical harnessc - Cable tie

7. Install both fuel pumps into VST. Secure low pressure pump with retainer and 2screws.

ob59378

a

b c d

a - Screwsb - Retainerc - Low pressure pumpd - High pressure pump

REFTORQUE


a 2 SCREW 22 2.5


Page 3B-44 90-889785 APRIL 2003

8. Secure float, needle and pivot pin assembly to separator cover with screw.

ob59382ab

c

d

a - Floatb - Needle

c - Pivot pind - Screw

REFTORQUE


d 1 SCREW 10 1

9. Install cover sealing ring on VST. Secure cover to VST with 9 screws.

ob59378

ob59374

ab

a - Sealing ringb - Screws

REFTORQUE


b 9 SCREW 37 4.2


90-889785 APRIL 2003 Page 3B-45

10. Apply 2-4-C with Teflon to fuel/water separator filter O-rings. Thread filter into VSTcover until filter seats.

ob59372

b

ob59375

a

95

a - Fuel/Water separator filterb - O-rings


berQuicksilver Part

Number

95 2-4-C with Teflon 92-802859A1 92-802859Q1


Page 3B-46 90-889785 APRIL 2003

Air Plenum InstallationSecure plenum to crankcase with 9 screws. Torque bolts in sequence shown.

ob00707

a

b

a - Air plenum b - Screws

REFTORQUE


b 9 SCREW (M8 x 45) 18 24.4

Vapor Separator Installation1. Secure vapor separator to air plenum with 3 bolts.

2. Reconnect pulse fuel pump vacuum hose.

3. Connect fuel inlet hose to pulse pump.

IMPORTANT: Only use tool 91-803146T (or Snap-On equivalent YA3080) to crimpfull circle clamps. Using a different tool could result in a crimp that is too loose, ortoo tight. Do not use screw type metal hose clamp as it may damage hose.

4. Secure fuel outlet hose with 15.3 mm full circle clamp (54-856880) using crimping tool91-803146T.


90-889785 APRIL 2003 Page 3B-47

5. Connect fuel return hose to vapor separator. Secure hose with retainer and screw

d

d

e

f

ab

b

c

d

g

ob00882

a - Screwsb - Pulse pump vacuum hosesc - Inlet fuel hosed - Fuel return hose

e - Retainerf - Screwg - Outlet fuel hose

REFTORQUE


a 3 SCREW (M8 x 60) 18 24.4f 1 SCREW (M6 x 12) 90 10.2


Page 3B-48 90-889785 APRIL 2003

Fuel Rail Removal

CAUTIONFuel system must be bled off prior to removal of fuel system components.

NOTE: Use Fuel/Air Pressure Gauge 91-16850--1 or 91-852087A1/A2 to de-pressurizeair hose first and then fuel hose.

1. De-pressurize fuel system.

2. Remove fuel injector harness from each injector by compressing spring clip with flattip screw driver while pulling on connector.

ob54871

57798

ce d

b

a

ob59586

f

a - Fuel pressure port(bottom of fuel rail)(De-sign 1)

b - Air pressure portc - Fuel injector

d - Harness connectore - Spring clipf - Fuel pressure port (Design 2)


90-889785 APRIL 2003 Page 3B-49

NOTE: Always remove fuel/air hose and fitting together by removing fitting retainer ratherthan cutting clamps.

IMPORTANT: If air hose is removed from barbed fitting, replace hose, as interiorsurface of hose will be damaged during removal.

3. Remove allen screws securing air and fuel hose retainers.

4. Remove fuel, water and air hoses from fuel rail.

ob59605

ob59609

ob59592

ab

c

d

e

a - Fuel hoseb - Water hosec - Fuel hose retainer allen screwsd - Air hose retainer allen screws (bottom of rail)e - Air hose


Page 3B-50 90-889785 APRIL 2003

NOTE: It is recommended that direct injectors remain in the cylinder head (if they are notto be replaced) while removing the fuel rail. The direct injectors have a teflon seal whichmay expand if the injector is removed from the head. This expansion may cause rein-stallation difficulty or require the replacement of the seal.

5. Remove 2 nuts securing fuel rail.

ob59602

a

a - Nuts

6. As fuel rail is removed, use a flat tip screw driver to hold direct injectors in cylinderhead.

ob59601

ab

ba - Fuel rail b - Direct injectors

NOTE: The fuel rail contains 3 fuel injectors, 1 fuel fuel regulator, and 1 air regulator.


90-889785 APRIL 2003 Page 3B-51

NOTE: Each fuel/air inlet or outlet hose adaptor has 2 O-ring seals. These O-rings shouldbe inspected for cuts or abraisions and replaced as required when fuel rail is disas-sembled for cleaning.

ob00774

e

f

g

i

a

a

a

b

c

d

h

j

k

l

a - Fuel injectorb - Fuel regulatorc - Air regulatord - Coolant outlet to tell-talee - Excess fuel return to VSTf - Water inlet for cooling fuel railg - Excess air to mufflerh - 751.5 kPa (109 psi) fueli - 655 kPa (95 psi) airj - Air pressure Schrader valvek - Fuel pressure Schrader valve (Design 1)l - Fuel pressure Schrader valve (Design 2)


Page 3B-52 90-889785 APRIL 2003

FUEL INJECTOR REMOVAL

1. Remove 2 screws securing injector.

NOTE: Use a cotter pin extractor tool in pry holes to remove injectors.

2. Gently pry up on injector to loosen O-ring adhesion and remove injector.

ob57967

b

ob57970

a

a - Screwsb - Pry holes

3. Inspect fuel injector orifices for foreign debris, O-rings for cuts or abraisions, and plas-tic components for heat damage. Replace components as required.

4. An ohm test of the fuel injector may be made by connecting test leads to injector termi-nals. Ohm reading should be 1.8 ± 0.1 ohm.

ob56002ob56124

a

b

c

a

b

c

a - Fuel injectorb - Fuel nozzlec - O-rings


90-889785 APRIL 2003 Page 3B-53

FUEL INJECTOR INSTALLATION

NOTE: Apply anti-seize grease (obtain locally) or 2-4-C with Teflon to fuel injector attach-ing screw threads.

1. Insert fuel injector into fuel rail with connector pins facing (inwards) towards center ofengine.

NOTE: Turn injector back and forth slightly to seat injector O-rings in fuel rail while secur-ing injector with retainer and 2 screws.

b 9 0

a

ob57970

9595

a - Injectorb - Retainer

c - Screws


berQuicksilver Part

Number

95 2-4-C with Teflon 92-802859A1 92-802859Q1

REFTORQUE


c 2 SCREW 70 8


Page 3B-54 90-889785 APRIL 2003

Fuel Pressure RegulatorThe fuel regulator is located on the port fuel rail.

a

ob59587

a - Fuel pressure regulator

The fuel pump is capable of delivering more fuel than the engine can consume. Excessfuel flows through the fuel pressure regulator, interconnecting passages/hoses, fuel cool-er, and back to the vapor separator tank. This constant flow of fuel means that the fuelsystem is always supplied with cool fuel, thereby preventing the formation of fuel vaporbubbles and minimizing the chances of vapor lock.

The fuel pressure regulator is calibrated to raise the fuel pressure to 96.5 kPa (14 psi)above the air pressure.

The fuel regulator is mounted on the fuel rail, near the top. This regulator relies on bothair and spring pressure to control the fuel pressure. Inside the regulator assembly is a 14lb. spring, this spring holds the diaphragm against the diaphragm seat. The contact be-tween the diaphragm and diaphragm seat closes the passage between the incoming fuel[from the electric fuel pump] and the fuel return passage.

When the engine is not running (no air pressure on the spring side of the diaphragm) thefuel pressure required to move the diaphragm is 96.5 kPa (14 psi).

When the engine is running, air pressure from the air compressor 648.1 kPa (94 psi) isrouted through the air passages, to the spring side of the fuel pressure regulator dia-phragm.

The air pressure 648.1 kPa (94 psi) and spring pressure 96.5 kPa (14 psi) combine to reg-ulate system fuel pressure to 744.6 kPa (108 psi) - or 96.5 kPa (14 psi) higher than theair pressure in the DFI system fuel/air rails.


90-889785 APRIL 2003 Page 3B-55

FUEL PRESSURE REGULATOR CUTAWAY

Regulator Closed Regulator Open

ÇÇ ÇÇ ÇÇ ÇÇ

1

23

4

5

67

8

9

10

11

12

13

1

23

4

5

67

8

9

10

11

1 - Top cover2 - Expansion plug3 - O-ring4 - Spring retainer5 - Spring6 - O-ring7 - Diaphragm seat

8 - Air rail9 - Air passage (from air compressor)

10 - Fuel return passage (to vapor separator)11 - Fuel inlet passage (from electric fuel pump)12 - Diaphragm assembly13 - Calibration screw (do not turn)


Page 3B-56 90-889785 APRIL 2003

FUEL REGULATOR REMOVAL

1. Remove 4 screws securing regulator and remove regulator.

2. Inspect regulator diaphragm for cuts or tears.

3. Inspect regulator housing O-ring for cuts and abraisions. Replace components as re-quired.

a

b ob57968 ob57969

fde

c

a

a - Screwsb - Fuel regulatorc - Diaphragm

d - Springe - Cupf - O-Ring


90-889785 APRIL 2003 Page 3B-57

FUEL REGULATOR INSTALLATION

NOTE: Apply a light coat of 2-4-C with Teflon to diaphragm surface and O-ring to aid inthe retention of diaphragm and O-ring on fuel rail during reassembly.

ee

ab

c

d

ob57975

ob57968

9595

a - Diaphragmb - O-ringc - Spring

d - Cupe - Screws

TubeRef. No. Description Mercury Part

NumberQuicksilver Part

Number

95 2-4-C with Teflon 92-802859A1 92-802859Q1

1. Position diaphragm on fuel rail.

2. Position O-ring on fuel rail.

3. Position spring and cup onto diaphragm.

NOTE: Apply anti-seize grease (obtain locally) or 2-4-C with Teflon to regulator attachingscrew threads.

4. Place cover over spring/cup/diaphragm assembly. Place the alignment pins from thespecial tool (91-889431) through two of the regulator cover mounting holes andthread them into the corresponding threaded holes in the fuel rail.

ob00205

aa

a - Alignment Pins


Page 3B-58 90-889785 APRIL 2003

5. Push the regulator cover against the fuel rail. While holding the cover down install twocover retaining screws through the open holes in the cover. Thread the two screwsdown until the head of the screw makes contact with the cover. Do not torque screwsat this time.

ob00204

a

a - Screw

6. Remove the alignment pins and install the two remaining screws.

ob56126

aa

a - Screws

REFTORQUE


e 4 SCREW

1st torque 5.6 Nm(50 lb. in.); 2nd

torque 7.9 Nm (70lb. in.)


90-889785 APRIL 2003 Page 3B-59

Air Pressure RegulatorThe air pressure regulator is located on the fuel rail.

ob59585

a

a - Air pressure regulator

The air pressure regulator is designed to limit the air pressure inside the rails toapproximately 648.1 kPa (94 psi).

The air regulator uses a spring (pressure) to control the air pressure. This spring648.1 kPa (94 psi) holds the diaphragm against the diaphragm seat. The contact areablocks (closes) the air inlet passage from the excess air, return passage. As the airpressure rises (below the diaphragm), it must reach a pressure equal to or greaterthan the spring pressure holding the diaphragm closed. Once this pressure isachieved, the spring compresses, allowing the diaphragm to move. The diaphragmmoves away from the diaphragm seat, allowing air to exit through the diaphragm seat,into the excess air passage leading to the air plenum.


Page 3B-60 90-889785 APRIL 2003

Air Regulator TroubleshootingCorrect air pressure and volume is critical to proper operation. Although air pressuregauge may show correct pressure, it does not confirm good volume. Air pressure shouldbe measured at the air schrader valve located near the middle of the fuel rail assembly.

YesNo

Is air pressure within [641.2 – 668.8 kPa (93 – 97 psi)] range at neutral idle position?

Momentarily pinch off air discharge hose.Does pressure rise very quickly to approximately 744.6 kPa (108 psi) or higher?

Air compressor output and volume OK.Air regulator faulty. Inspect regulator

diaphragm, spring and cup.

Yes

Obstruction at compressor inlet or outlet or failed compressor.

No

Momentarily pinch off air discharge hose.Does pressure rise very quickly to approximately

No Yes

Air regulator OK. Compressor output low.Check compressor.

Air compressor output and volume OK.Regulator OK.

744.6 kPa (108 psi) or higher?

Regulator Closed Regulator Open

ÇÇ ÇÇÇÇ ÇÇ

1 2

34

5

6

7

8

9

10

12

11

1

12

10

9

8

7

6

5

43

2

1 - Top cover2 - Expansion plug3 - Spring retainer4 - Vent5 - Spring6 - Diaphragm seat

7 - Air rail8 - Air passage (from air compressor)9 - Excess air passage (to exhaust adaptor)

10 - Fuel inlet passage (from electric fuel pump)11 - Diaphragm assembly12 - Calibration screw (do not turn)


90-889785 APRIL 2003 Page 3B-61

AIR REGULATOR REMOVAL

NOTE: Due to the stiffness of the regulator spring, it is recommended that RegulatorInstallation Tool 91-889431 be utilized when removing the air regulator cover. Clean areaarea around regulator prior to disassembly to keep debris out of fuel system.

1. Remove two opposing screws from regulator cover and install regulator installationtool.

ob59360

2. With installation tool applying pressure to regulator cover, remove remaining coverscrews.

ob59357

3. Loosen installation tool and remove cover.

ob59356


Page 3B-62 90-889785 APRIL 2003

4. Inspect regulator diaphragm for cuts or tears. Replace as required.

a a

b

c

d

e

ob57974

a - Screwsb - Air regulator coverc - Diaphragm

d - Springe - Cup

AIR REGULATOR INSTALLATION

NOTE: Apply a light coat of 2-4-C with Teflon to diaphragm surface to aid in the retentionof diaphragm on fuel rail during reassembly.

1. Remove fuel rail from engine and place rail in a horizontal position when assemblingair regulator to rail to prevent damage to diaphragm.

NOTE: Mount fuel rail in vice to keep rail stable while reassembling.

2. Position diaphragm, spring and cup onto fuel rail with fuel rail in horizontal position.

NOTE: Apply anti-seize grease (obtain locally) or 2-4-C with Teflon to regulator attachingscrew threads.

NOTE: Due to the stiffness of the regulator spring, it is recommended that RegulatorInstallation Tool 91-889431 be utilized when installing the air regulator cover.

a

c

b

a - Cupb - Springc - Diaphragm


90-889785 APRIL 2003 Page 3B-63

3. Position cover over diaphragm spring and install Regulator Installation Tool91-889431.

ob59356

a

a - Regulator Installation Tool (91-889431)

4. Gently apply pressure to cover with installation tool until cover is just seated againstfuel rail. Do not over tighten center screw during installation or damage to regulatorcover may occur.

ob59357

5. Install two retaining screws. Remove installation tool. Install remaining two screws.

ob59360

aa95

95

a - Screws

NOTE: After installation of rail on engine, verify function of regulator with pressure gaugeand check for air leaks using soapy water.

TubeRef. No. Description Mercury Part

NumberQuicksilver Part

Number

95 2-4-C with Teflon 92-802859A1 92-802859Q1

REFTORQUE


a 4 SCREW 70 8


Page 3B-64 90-889785 APRIL 2003

Fuel Rail CleaningAfter all fuel injectors, air regulator, fuel regulator, inlet hoses and outlet hoses have beenremoved, the fuel rails may be flushed out with a suitable parts cleaning solvent. Use com-pressed air to remove any remaining solvent.

IMPORTANT: If mechanical failure should occur in the air compressor or direct in-jector assemblies, the fuel rail and attached hoses should be removed and flushedwith a suitable parts cleaning solvent to remove any metal debris.

Direct Injector Removal1. Remove harness connectors from direct injectors.

2. Remove direct injector from cylinder head using

ob00783

b

a

91-883521

a - Direct Injector (3 each)b - Direct Injector Removal Tool 91-883521


90-889785 APRIL 2003 Page 3B-65

3. Inspect injector teflon sealing ring (white) for signs of combustion blowby (teflon ringwill be streaked brownish black). If blowby is present, replace teflon sealing ring. Ifblowby is not present, sealing ring may be reused.

4. Inspect O-rings and teflon ring for cuts or abraisions. Replace components as re-quired.

5. If teflon seal requires replacement, use Teflon Seal Installation Tool to slide new sealonto injector. Following installation of teflon ring, the Teflon Ring Sizing Tool can beused to compress the teflon seal to aid in the installation of the injector into the cylinderhead.

d

ab

c e e

91-851980-1

f

ob57983

a - Teflon sealing ringb - O-ringc - Teflon seal

d - Seal Installation Tool (91-851980--3)e - O-ringf - Teflon Ring Sizing Tool (91-851980-2)


Page 3B-66 90-889785 APRIL 2003

NOTE: It is recommended that a digital ohm meter be used due to it’s improved accuracywhen measuring small ohm readings inherit with direct injectors.

6. An ohm test of the direct injector may be made by connecting test leads to injectorterminals. Ohm reading should be 1.3 ± 0.3 ohm.

7. An ohm test to determine if direct injector windings are shorted to ground can be madeby connecting one ohm lead to either injector pin while touching the other ohm leadto the injector metal case. There should be no continuity. If there is continuity, the inter-nal windings are shorted and the injector must be replaced.

ob00051

ob00052

ba

a - Direct injector ohm test (1.3 ± 0.3 ohm)b - Direct injector short to ground ohm test (no continuity)


90-889785 APRIL 2003 Page 3B-67

Direct Injector Leak Test1. Attach Gearcase Leakage Tool to discharge side of injector.

ob57714

ab

a - Gearcase Leakage Tool (FT-8950)b - Direct injector

2. Pump up leakage tool to indicate 172.4 - 206.8 kPa (25 - 30 psi).

3. Direct injector should not leak down more than 3.5 kPa (1/2 psi) in 1 minute.

4. If injector does not meet the above specifications, replace injector.

NOTE: If cylinder block is going to be replaced, remove cup washers from each direct in-jector port by prying out with a flat tip screwdriver. Reinstall washers with retainers intonew cylinder block. Washers provide tension between direct injectors, cylinder head andfuel rails.

ob59600

b

a

a - Cup washerb - Retainer


Page 3B-68 90-889785 APRIL 2003

Fuel Rail and Direct Injector Installation1. Use Teflon Ring Sizing Tool (91-851980-1) to compress new teflon sealing rings prior

to installation of injector into cylinder head.

2. Carefully slide fuel rail over mounting studs and onto direct injectors.

IMPORTANT: ALL fuel and air hoses attached to the fuel rails MUST be secured withstainless steel hose clamps.

3. Secure each fuel rail with 2 nuts.

4. Reinstall direct injector harness connectors.

ab

ob59608

a - Nutsb - Direct injector harness connectors

REFTORQUE


a 2 NUT 33 44.7


90-889785 APRIL 2003 Page 3B-69

Air CompressorAir compressor is a single cylinder, water cooled and lubricated by the outboard oil pump.

Air Compressor SpecificationsAir Compressor Type

Compressor Output

Reciprocating Piston(1.14 to 1 ratio with engine RPM)

@ Idle – 648.1 kPa (94 psi)

Cylinder Block Displacement 60 cc (3.66 cu. in.)

Cylinder Bore Diameter (Standard)Taper/Out of Round/Wear Maxi-mumBore Type

52.0 mm (2.0472 in.)

0.025 mm (0.001 in.)Cast Iron

Stroke Length 27.9 mm (1.100 in.)

Piston Piston Type Aluminum

Piston Diameter

Dimen-sion “A”at RightAngle(90°) toPiston Pin

0.300 in.

51.95 ± 0.010 mm(2.0453 ± .0004 in.)

Piston Ring End GapTop Ring

Middle Ring

Bottom Ring

0.15 - 0.30 mm(0.0059 - 0.0118 in.)

0.15 - 0.30 mm(0.0059 - 0.0118 in.)

0.10 - 0.35 mm(0.0039 - 0.014 in.)

Reeds Reed Stand Open 0.25 mm (0.010 in.)


Page 3B-70 90-889785 APRIL 2003

COMPRESSOR REMOVAL

1. Disconnect battery cables from battery terminals.

2. Remove top cowling.

3. Remove flywheel cover.

4. Use 3/8 inch drive on belt tensioner arm to relieve belt tension. Remove belt.

ob00397

a

b

a - Belt tensionerb - 3/8 in. drive


90-889785 APRIL 2003 Page 3B-71

CAUTIONIf engine has been recently run, air pressure outlet hose fittings may be extremelyhot. Allow components to cool off before beginning disassembly.

NOTE: Remove 2 screws securing retainer plate to remove air pressure outlet hose. In-spect O-rings on air pressure hose fitting for cuts or abraisions. Replace O-rings as re-quired.

5. Remove air pressure outlet hose.

ob59605

a

b

a - Air pressure outlet hoseb - Screws

6. Remove air compressor water outlet hose.7. Disconnect air compressor temperature sensor connector.8. Disconnect compressor air inlet hose.

ob00523ob59611

a

b c

a - Compressor water outlet hoseb - Compressor temperature sensor connectorc - Compressor air inlet hose


Page 3B-72 90-889785 APRIL 2003

9. Disconnect air compressor oil inlet hose.

10. Disconnect water outlet hose (to fuel rail).

11. Disconnect excess oil return hoses.

ob00784

a

b

c

d

a - Air compressor oil inlet hoseb - Water inlet hosec - Excess oil return hosesd - Oil return check valves (3)

12. Remove 3 screws securing air compressor to outboard and remove compressor.

ob00772

a

a - Screws


90-889785 APRIL 2003 Page 3B-73

Notes:


Page 3B-74 90-889785 APRIL 2003

Air Compressor Disassembly/ReassemblyIMPORTANT: If an internal failure of the air compressor has occurred, all airhoses, excess oil return hose check valves, fuel rails and injectors should bedisassembled and inspected for metal debris. Failure to remove all metal debriswill result in poor performance and/or powerhead failure.

NOTE: If cylinder bore is scored, air compressor must be replaced as an assembly.

NOTE: Piston Installation – use a metal hose clamp for piston ring compressor. Staggerpiston ring openings.

NOTE: The piston and rings are not sold separately. They must be replaced as an assem-bly. The connecting rod and bearings are not sold separately. They must be replaced asan assembly. End cap bearing and seal are not sold separately. End cap must be replacedas an assembly.

a

bc

d

g

hi

f

9

9

9

7

7

14

14

e

c

7

14

14

a - Screw (pulley)b - Screw (tensioner)c - Screw (end cap)d - End cap assembly (inspect bearing

for roughness)e - O-ring (inspect for cuts or abrai-

sions)

f - Reed plate (inspect for broken or chippedreeds/stops) maximum reed stand-open –0.254 mm (0.010 in.)

g - Screw (4 each)h - Temperature sensori - Fitting (outlet)


90-889785 APRIL 2003 Page 3B-75

Tube Ref.# Description Mercury Part Number Quicksilver Part Num-

ber

7Loctite 271 – Thread

Locker92-809819 92-809819

9Loctite 567 PST Pipe

Sealant92-809822 92-809822

142 Cycle Premium Out-

board Oil92-802813A1 92-802813Q1

REFTORQUE


a 3 SCREW 100 11.3

b 1 SCREW 16.7 22.6c 1 SCREW 100 11.3d 3 SCREW 18 24.4h 4 SCREW 20 27.1i 1 TEMPERATURE SENSOR 13 1.4j 1 FITTING 25 33.9


Page 3B-76 90-889785 APRIL 2003

Air Compressor End Cap/Crankshaft Removal and ReassemblyDISASSEMBLY

1. Remove flywheel cover.

2. Use 3/8-inch drive on belt tensioner arm to relieve belt tension, and remove belt.

3. Remove the 3 bolts that retain the pulley to the pulley flange.

ob00397

b

c

a

a - Pulley retaining bolts (3)b - Tensionerc - 3/8 in. square drive


90-889785 APRIL 2003 Page 3B-77

4. Remove the 4 bolts that retain the end cap to the compressor body.

a

ob57809

a - End cap retaining bolts (4)

5. While rotating the pulley flange alternately clockwise and counterclockwise about 1/8to 1/4 turn, pull outward on the pulley flange. Continue rotating until the end cap as-sembly has been removed from the compressor body.


Page 3B-78 90-889785 APRIL 2003

REASSEMBLY

1. Lubricate end cap O-ring and O-ring contact area in compressor body with two cycleoil.

2. Slide the new end cap assembly into the compressor body, keeping the connectingrod journal lined up with the open end of the connecting rod, until the crankshaft justenters the open end of the connecting rod.

a

b

a - Connecting rod open endb - Crankshaft connecting rod journal

3. While rotating the pulley flange clockwise and counterclockwise, push the end capinto the compressor. Continue rotating the flange until the end cap is all the way downagainst the compressor body.

4. To confirm that the connecting rod journal has properly engaged with the connectingrod, rotate the flange until you feel resistance from the piston trying to compress airin the cylinder.


90-889785 APRIL 2003 Page 3B-79

5. Apply Loctite 271 to the threads of the end cap retaining screws and torque to specifi-cation.

a

ob57809

7

a - End cap retaining screws (4)


ber


Locker92-809819 92-809819

REFTORQUE


a 4 SCREW 100 11.3


Page 3B-80 90-889785 APRIL 2003

6. Apply Loctite 271 to the pulley retaining screws. Torque screws to specification.

ob00397

a 7

a - Screws


ber


Locker92-809819 92-809819

REFTORQUE


a 3 SCREW 190 21.5

7. Install compressor/alternator belt.

8. Run engine to confirm that compressor is functioning correctly.


90-889785 APRIL 2003 Page 3B-81

Air Compressor Flow Diagram

b

ob59589

a

c d

e

fg

h

i

k

l

m

n

o

p

j

a - Excess air return to adaptor plateb - Air mufflerc - Water outlet from fuel raild - Air regulator – 648.1 ± 13.8 kPa (94 ± 2 psi)e - Fuel regulator – 744.6 ± 13.8 kPa (108 ± 2 psi)f - Fuel railg - Fuel inlet to fuel rail – 744.6 ± 13.8 kPa (108 ± 2 psi)h - Excess fuel return to VSTi - Air pressure test valve (hidden)j - Water inlet hose to air compressork - High pressure air to fuel rail – 648.1 ± 13.8 kPa (94 ± 2 psi)l - Air compressor

m - Compressor air inletn - Air filtero - Air inletp - Oil tank/air attenuator


Page 3B-82 90-889785 APRIL 2003

Air Compressor Pressure Test1. Install Pressure Gauge Assembly 91-852087A1/A2/A3 to fuel rail pressure test

valves.

NOTE: After 15 seconds of cranking engine with starter motor, air pressure gauge shouldindicate 648.1 ± 13.8 kPa (94 ± 2 psi) and fuel pressure gauge should indicate 744.6 ±13.8 kPa (108 ± 2 psi).

ob59594

a b

c

d

e

a - Air pressure gauge – should indicate 648.1 ± 13.8 kPa (94 ± 2 psi)b - Fuel pressure gauge – should indicate 744.6 ± 13.8 kPa (108 ± 2 psi)c - Air pressure test valved - Fuel pressure test valve (Design 1)e - Fuel pressure test valve (Design 2)

Fuel/Air pressures within the above listed ranges are important, but the difference be-tween the two pressures is even more important. There should be a 96.5 ± 6.9 kPa (14± 1 psi) difference. If the pressure difference is outside this range, confirm gauge accura-cy. Reversing the dual pressure gauge connections is a good way to confirm gauge accu-racy.


90-889785 APRIL 2003 Page 3B-83

NOTE: Proper pressure does not necessarily confirm good fuel/air volumes.

To confirm good air volume, momentarily pinch off the air discharge hose on the port sideof the engine. Pressure should rise very quickly to about 827.4 kPa (120 psi) or higher.

a

0b59595

a - Air discharge hose pinched off to raise pressure

If air pressure does not rise quickly to 827.4 kPa (120 psi), the following items should bechecked:

Dirty air compressor air filter.

Leaking air hoses.

Broken air compressor reed valves.

Scuffed air compressor piston.

Defective direct injector.

To confirm good fuel volume, momentarily pinch off the fuel return hose on the port sideof the engine. Pressure should rise very quickly to about 827.4 kPa (120 psi) or higher.

a

0b59596

a - Fuel discharge hose pinched off to raise pressure

If fuel pressure does not rise quickly to 827.4 kPa (120 psi), the following items shouldbe checked:

Proper fuel level in vapor separator tank.

Check low pressure fuel pump output.


Page 3B-84 90-889785 APRIL 2003

Fuel Injector TestIf a fuel injector, fuel pressure regulator or injector O-ring is leaking, fuel will enter the airpressure side of the rail. Fuel in the air side of the rail will cause spark plug fouling. A sim-ple test is to connect a pressure gauge to the fuel pressure test port and turn the ignitionkey to the “ON” position.

NOTE: Prior to making this test, prime the fuel system using the primer bulb in the fuelsupply hose to confirm that the Vapor Separating Tank (VST) is filled with fuel.

• The electric fuel pumps should run for about 2 – 3 seconds.

• The fuel pressure should rise to about 227.5 – 296.5 kPa (33 – 43 psi) at the fuelrail when the pumps are running.

• Fuel pressure at the boost pump Schrader valve on the VST should be 137.9 –206.8 kPa (20 – 30 psi).

• When the pumps stop, the pressure should level off to about 68.9 – 137.9 kPa (10– 20 psi) and hold.

• If the pressure drops below 68.9 kPa (10 psi) quickly, it is an indication of a fuelleak.

If a fuel leak is suspected, proceed as follows:

• Remove the fuel rail retainer nuts.

• Remove the water outlet hose.

• Slide the rail away from the cylinder block (keep the direct injectors in place in thecylinder block).

• Turn the ignition key to the “ON” position to pressurize the system and look for fuelleaks at the injector openings.

• Replace any leaking injectors.

ob59486

a

b

a - Fuel rail pulled back from cylinder blockb - Fuel injector openings


90-889785 APRIL 2003 Page 3B-85

FUEL PRESSURE AND AIR PRESSURE TROUBLESHOOTING CHART

PROBLEM CORRECTIVE ACTION

Fuel pressure and air pressure are both low 1. Inspect air compressor air intake for blockage.

2. Inspect air compressor for scuffing of cylinderwall. Inspect for broken reeds and/or reed stops.

3. Air Regulator – inspect diaphragm for cuts ortears on diaphragm and rail.

Fuel pressure low or fuel pressure drops whilerunning (air pressure remains normal)

1. Each time key is turned to the “RUN” position,both electric pumps should operate for 2 se-conds. If they do not run, check 20 ampere fuseand wire connections.

2. If pumps run but have no fuel output, check va-por separator (remove drain plug) for fuel.

3. If no fuel present in vapor separator, check fuel/water separator for debris. Check crankcasemounted fuel pump for output.

4. High and low pressure pumps are on the sameelectrical circuit. Amperage draw for both com-bined should be 10 – 14 amperes. If amperageis low, check for insufficient fuel to pumps or anopen circuit in one or both pumps. If amperageis high, check low pressure pump output. Itshould be 137.9 – 206.8 kPa (20 – 30 psi). Ifpressure is low, replace low pressure pump. Ifpressure is correct, replace high pressure pump.

5. Fuel Regulator – inspect diaphragm for cuts ortears.

Fuel pressure high and air pressure is normal 1. Debris blocking fuel regulator hole.

2. Faulty pressure gauge

Fuel and air pressure higher than normal 1. Debris blocking air regulator passage.

2. Air dump hoses (rail to muffler) blocked/plugged.

3. Air muffler plugged.

pulse crankcase driven fuel pump fuel system...pulse crankcase driven fuel pump 90-889785 april 2003...

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