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RIDERS MANUAL

WELCOME RUPP RIDER!

We are pleased at the confidence you have shown inselecting a Rupp snowmobile from the many modelsavailable. Your Rupp snowmobile represents the finestin engineering, design, and workma nsh ip which aretraditiona l at Rupp Industries.

We ask that you read this manual caref ully so youwilt be able to give your snowmobi le the care andconsideration it deserves. With such atte nt ion, you' llenjoy all the perform ance and durability built Intoyour new Rupp mach ine. Make it a point to familiar­ize yourself with every phase at your snowmobile'soperation and care.

Your complete satisfac tion is our goal. Aupp dealersstand ready to help you with your maintenance needs,repairs, parts or any help you may need.

Than k you for choosing Rupp.

INDEX1975NITRO F/ARIDERSMANUAL Operation Information

Safety Precaut ions

Page

2

5

Maintenance . . . .... .. .. .• .... . . •. . .. .. • . . .. 6

Trouble Shooting . .... . .. .. • • . . . .. • .... . • .... 14Rupp /MU",I••, Inc .,n, A/rpo rl ROld"'. nll/, Id , Ohio 44llO3

Storage . . . 15Alllnrorm.l/on, JIIl/tfr.tlon. and .~clflc."on. cOn­,,'n.d In rhl, m.llu.1 . r. bu.d On f'" ,ar•• r prod­u" Iflform. tion .~. II.lJl••t t'" rim. 01 lI ublle. /l OII,TIl. ,/girt I. ,...,...d to mal, cll'''Q' ' . t '11)' lim•../Ill our noF/c•.

Set-Up Instructions . . ... ... •• . . . . . • . . . . • • .. . . 15

Specifications ' " . . . .• , ' , , , .. ' , " 16

·"OPERATION INFORMATION

FUEL

The z-cycte air coo led engine In yourRupp snowmobile uses a gasoli ne andoil mixture for luel. Use Rupp SuperSynthe llc lubr icant or a known brand ofSAE 40 dil uted z-cycte (ai r cooled type)eng ine oil. GASOLINE TO Oil MIX­TURE OF 20 TO 1 MUST BE USED. USEONLY PREMIUM GRADE GASOLINE' ,MINIMUM OCTANE 92. DO NOT USEWHITE GAS, NAPTHA, METHANOL,OR OTHER FUELS.

FUELMIX'NGPROCEDURE

WARNING: Observe fire preventionrules. Mix luel outdoors whenever pos­sible or in a well -ventila ted location.Put out all ctqarettes and never mix fuelnear an open lIame.

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Thoroughly mix 1 quart 01oi l to live U.S.gall ons 01 premium gasolin e in a cleancon tainer. Measure gasoline and oil ac­cu rately . Pour about a gallon 01 gaso­line into the con tainer fi rst. Add thequart of oil and shake vigorously to mixthoroughly. Add the balance of gaso­line and mix again. At temperatures be­low freezing, oil does net mix readilywith gasoline and extr a care must betaken to get a good mixture.

Cleanliness is important in mixinglue l. A small part icle of d irt can causecarburetor troub le. Always use freshgasoli ne.

• Non-or-lo w leaded gasol ines havenot been approved for z-cycre engines.

Gum and varnish deposits found in oldgasoline may cause carburetor troubleand spark plug loul ing. DO NOT POUROIL DIRECTLY INTO THE SNOWMO­BILE FUEL TANK.

Carburetor adjustments are sensitiveto fuel mix ture variations which resultf rom use of diffe rent gaso line and oi lratios due to inaccurate measuring ormix ing. Be cons istent, Prepare eachbatch of fuel exactly the same as previ­ous one. Using more than the recom­mended propor tio n of oi l will causeerrati c ca rbu reuon. excess ive smokingand faster-than-normal carbon accu ­mulation. Using less al l wi ll result indamage to the engine.

After mix ing, pour fuel into the snow­mobile fuel tank. Take care when fill inggas tank. Do not spi ll fuel on the rna­chine. WARNING : DO NOT FILL GASTANK WHILE ENGINE IS RUNNING ORHOT!

Spill ed gasoline on a hot engine or ex·baust pip e will c reate a fire hazard.Avoid problems by allowing the engineand exhaust system to coo l down prior10 addi ng gasol ine. Use a l unnel andpour carefully. Wipe up any spill ageat once.

IGNITION/LIGHT SWITCH

The key s..... itch on the dash con trols allelec tr ica l functi ons of you r snowmo­bile. The "off " posi tion grounds theignition circui t and stops the motor.The head l ight and tail ligh ts are cper­ated by turning the key 10 the "ligh ts"positi on with the motor running.

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0-<:,. I O~

~~-START

BRAKE

The brake con trol lever is at the lefthandgrip on the hand lebars. To operatebrake, squeeze rever with fingers.WARNING : CHEC K BRA KE CO N·TROLS FOR PROPER OPERATION BE­FORE STARTING ENGINE.

THROTILE

The thro tt le control lever, or accelera­tor, is attached 10 the handg rip on theright-hand side of the handlebars. De­press the thro ttle lever to move thevehicle forward and to increase speedand power. When the lever is released,engine speed wi ll return to id le. WARN·ING: CHECK THROn LE CONTROLSTO BE SURE THROTTLE RETURNS TOIDLE FREELY AND NORMAL FORCETO OPERATE BOTH CARBURETORSIS FELT BEFORE STARTING ENGINE.NEVER STAR T EN GINE WI THOUTF IR ST C HEC K I N G BRA KE ANDTHROTTLE CONT ROLS.

STEERING

Steering is controlled by the handle­bars. Turning the handl ebars right orleft wi ll turn the vehicle into the direc­tion 01 travel desired,

CHOKE

Nitro F/A models have a choke leveron the dash (see Illustra tion). Place thechoke lever in " choke" positio n torichen fuel l air mixtur e lor col d startsand during Init ial warm up per iods .Throttle must be closed (idle posit ion)dur ing choke operation. Choke will notlunc tion if throllie is open. Do notchoke a war m engin e or " fl ood ing" ofthe engine can occur.

KILL SWITCH

The kill sw itch on the hand lebar con­trots has three positions. The centerposi t ion is the " run" positio n. Theother two positions g round the igni tionwhich stops the engine. Check positionof swi tc h belore starting engi ne. USEKILL SWITCH TO STOP THE ENGINEIN AN EMERGENCY.

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4. Place c hoke lever in " CHOKE"pos ition, turn the igni tion key to " ON"po sition.

WARNING: WHEN APPLYING PARTIALT H ROT TLE TH E T ORQUE CO N­VERTER CAN UNEXPECTANTLY EN­G AG E AN D C A US E VE H IC LE T OLURCH FORWARD. BE SURE THROT·TLE AND BRAKE CONTROLS OPER­ATE FREELY AND AREA IN FRONT OFMACHINE IS CLEAR BEFORE START­ING ENGINE.

5. Grasp manual slarting handlefirmly and pull outward slow ly until en­gagement of ratchet mechanism can befelt. Then con tinue to pull outward wi tha vig orous stroke. Do not allow rope tosnap back. Retain grip on handle andallow rope to rew ind slowly. 0 0 not pullrope to end of travel. Return ch oke toopen posi tion alter two or three pull sof manual starter or af ter eng ine hasfired I" avo id engine flooding.

TETHER SWITCH

Tether switch is located in the cente r01 the dash. When the tether co rd ispulled the swit ch " kill s" the engine andthe tether cord " pops" apar t. To resetswi tc h 10 run position, push red sleeveon cord into switch rec eptac le. Wearthe black strap supp lied snugly aroundyour waist. Attach lanyard c lasp 10 " 0 "ring on strap. CAUTION : COMPLETELANYARD HOOK UP BEFORE START­ING ENGINE.

STARTING

The sta rter handl e is loca ted on theright side of the engine. This sta rteris an automatic rew ind type and wi llprovide many hours or trccbre-tree ser­vic e by observing the prope r starti ngtechnique :

1. 8e sure Ihat fue l tank contains asuffi c ient amount 01 properly mixedlue l.

2. Be sure tether lanyard is hookedup 10 your waistband.

3. Check 10 see Ihat tether and killswit ch are in " run" poetuc n.

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NOTE:throttl e

Choke only functi onsis in idle posit ion .

when

6. When engine starts, utne ch oke isstill on , return choke lever 10 " off"(normal running) position. If enginefall ers. actuate c hoke as needed . 00not use cho ke when starting a warmengin e. or flooding may occur.

7. DO NOT use o r ope rate the auto­matic rewind starter white the engineis running, or damage may occur 10 thesta rter assembly.

EMERGENCY STARTING

If. for any reaso n, the rewind starter be­comes inope rative, the engine can bestarted via an emergency starter ropewhich should be carried in too l box atall t imes.

1. Remove four capscrews which ss­cure rew ind starter 10 fan housing, andremove complete rewind starter hous­Jng assem bly.

2. Wind length of rope arou nd Ihestarter sheave in a c lockwise direction .

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3. To star t the engine, pull the ropewith a vigorou s stroke. foll owing theprocedure previously outl ined .

CAUTION ; STAY CLEAR OF STARTERSHEAVE WHEN OPERATING SNOW·M OB IL E W ITH RE WI N D ST A RT ERHOUSING REMOVED TO AVOID SERI·OUS INJURY. HAV E REWIND STARTERREPAIRED AND REINSTALLED BE­FORE FURTHER USE.

SAFETY PRECAUTIONSYou r Nitro F/ A is a specialized highperformance machine and is not de­signed lor the novice rider. DO NOTOPERAT E T H IS VEH IC LE U NL ESS

YOU ARE AN EXPERIENCED SNOW­MOBILE RIDER.

1. Always wear a helmet and faceshield. The Nitro F/ A is not equippedwith a wind shield and yo ur face shie ldmust replace Its function .

2. Never start engine without l irsthooking tether sw itch co rd 10 straparound your waist.

3. Al ways check your throttle andbrake controls BEFORE you turn onthe ignit ion key .

4. Never run eng ine wi th the torq ueconve rte r gua rd removed.

5. Observe all cau li on dec als on thesnowmob ile.

6. Never smoke white refueling orwhi le checking Iuettevet . Fuel gives offinflammable vapors which can igniteinslantly without warn ing. Install gastank cap securely.

7. Start each ride wit h a ful l tuellank. Check Iuet supp ly every Vz hour.Always leave yourse lf a safety margin.A snowmobile does not Irave l the same

di stance each time on the same amoun tof fuel.

8. Do not overload your machine.Your machine is designed for the driveron ly. NO PASSENGERS.

9. Always carry emergency male­rials, exi ra spa rk plugs, torque ccover­lor be lt , toots. knife, and supp lies. Keepyour Owner's Manual wit h the veh ic le.

10. Jumping is fun but ha rd on themach ine. This type of act ivity can putyou and you r machine out of co mmts­stcn lor the season.

11. Do not over-d rive your brakes.Tes l b rak ing di stances at va ri o usspeeds on the snow and ice conditio nsin wh ich you will be operating.

12. If you are plann ing to explor enew areas, leave wo rd wilh someone01 your approx imate whereabouts andestimated l ime of retu rn. Remember, asnowmobile can travel further in 15minutes than you can walk In a day.

14. Do not run snowmobile leanedover or on a stenc to cl ear track . Flyingobjects thrown fr om the trac k are ex­tremely dangerous.

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HEADLIGHT BULBREPLACEMENT

The headl ight has a replaceable bulb .

To rep lace a bul b:

1. Open shroud .

2. Headlight assembly is located onthe underside of the shroud.

3. Unscrew plastic cap to removehead lig ht bu lb and sealing gasket.

4. Unpl ug wiring hamess from bulband replace wi th new bulb.

5. When reinstall ing socket in theheadlight be sure the locating notch" lines up,"

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HEADLIGHTADJUSTMENT

The headlight aim is adjustable. Fouradjustment screws are located in thefron t 0 1 the head ligh t. Turn the screwsto move the headl igh t beam in the de­sired direction unt il proper adj ustmentIs ach ieved .

TAILLIGHTS

The tai lli ght Is a single tail / stop tightwith replaceable bulb .

To replace a taill ight bu lb ;

1. Remove two screws retaining tail ­ligh t lens.

2. Remove the taillight lens by insert­ing a screwdriver between the ta illightlens and housing and pry off lens.

3. Pull out defective bulb and replace.

4. Reassemb le gaske t and lens tohous ing. Be sure " Top" of lens is at topof body. Secure with screws.

INSTRUMENT LIGHTSYour snowmobile is equi pped wi th atachometer wi th an Ill umin ating l ight.

The lights have a push in type socket.The bulbs can be removed ' rom thesocket by pushi ng in and turning coun­terc lockwise.

DRIVE BELTREPLACEMENT

The dri ve bell is a vttet pa rt of the d rivemech anism. Frequent inspection of Ihebelt is recommended and jf it is found10 be seve rely worn, rep lace as follows;

l . Raise the cen ter shroud. unlatchand raise bell guard.

2. Apply brake 10 prevent fixed halfof d riven flange from tu rni ng . Rotatethe movable hal f of Ihe driven flangeand push it towa rd center of vehic le(compressing the spring). Then, slidethe torque converter bell over the topof the movab le drive n flange.

3. After removing the belt from thedriven sheave . you can work i t off thedrive shea ves.

4, Install new be ll in reverse order.Do not force or use tool s 10 pry thebelt into pl ace, as this could cu i orbr eak the co rds in the belt

I-~ ITORQUE CONVERTOR

The tor que conve rtor does not requireany main tenance other than period iclubrica tion of the shafts and rampsupon whic h the movable sheaves slideand flyweight pivo t points of the d rivetorque convertor cover. Use a smallamount of g raphi te base low temp era­ture lubricant.

Excessive lubricant will " throw off"and cause belt sl ippa ge. Torque co n­verto r she ave a lign men t should bechecked periodically since misaliqn­ment 01 the torque convertor sheaveswill cause premature belt fa ilure.

l . Remove the torque converto r bell.

2. Place a straig htedge against themoveab le driv en fl ange and use to seethat the fixed drive flan ge is offset V2inch inboard and parallel to drivenflange. Check al ignment at top andbotto m of driven flange.

3. Align by looseni ng bo lts that se­cure rubber engine mounts and shifteng ine to cor rect posit ion . Be certaind rive and d riven lIanges rema in par­allel. If chain case is not perpendi cularshim by installi ng washers betweenchai n case and chassis.

4. The chain case brace has an ad­justable bracket to con trol tw ist andalignment of the chain case. l oosenlock nut, then rotate bolt 10 obtain de­sired alignment, then secure lock nut.

5. Check center distance betweenthe drive and driven clutch assemblies.Dis tance should be 2 to 2~ inches forop timum perform ance.

If a torque conver tor sticks or operateser ratically. i t may be necessary to dis­assemble and clean shalt and bearings.

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PERFORMANCEALTERNATES

The following adjustments can bemade on your machine to give it Ihe" custom performance" you desire.

(a) Th e d riven t o rq ue conver to rspring is factory set for optimum per­formance under most cond itions. Whena machine is used wit h extra heavyload, deep snow, steep hills or lake iceit may become desirable to have yourdealer change Ihe spring setting 10pro­vide improved performance under yourfun ning condit ions .

(b) Optional sprockets lor higher orlower gea ring .

(c) Drive torque convertor springs.to change engagement RPM's and shilt­ing pattern.

CAUTION: The above modificationsshould be performed only by a com­petent snowmobile mechanic. Be cer­ta in changes will not cause the engineto overspeed.

(d) For best performance. the 440FI A should ope rate at 8500 RPM, the340 at 8750 RPM.

B

SELF ADJUSTER BRAKEThis brake system will need little o r nomain tenance . Check the brake pucks(wear shoes) for wear occasionally.

When the pucks are worn th in, con tactyou r Rupp dealer lor replacemenL

CHAINCASEThe lubrication level in the chaincaseshou ld be checked per iodically andchanged at the end 01 each season. Tocheck the che lncese oil, remove theoil fill plug wi th the machine on a levelsurface. The oil should be level withbottom of the fill plug hole. Use Dexron

qual illed automatic transmission oi l orhigh quali ty moto rcyc le chain oil sui t­able lor low temperatures.

DRIVE CHAIN TENSIONTo check chain tension, remove thecha in inspection rubber plug or coverand press on the side of the cha in.Chain tension is co rrect when the chainis no t so tight as to be preloaded, anda slight ~" deflection (slack in chain)is noticeable when pressing on thecha in .

NOTE: Over·tight tens ion on cha Incan cause premature w ear o nsprockets, bearings, and chain . Toomuch slack in chain could cause chainto " jump" teeth on the sprockets, withsubsequent damage to sprockets, cha inand/or chaincase.

If the chaIn tension is incorrect :

1. Remove left tuned pipe and mut­fler assembly.

2. Tip the machi ne on the right sideto prevent cbatncase oil leakage whenthe cover Is removed.

3. Remove the cha incase cover byremovlnq the two retaini ng nuts.

4. Loosen the three retain ing nuts se­curing the eccentric barrel approxi­mately two complete turns and l ightlytap bolts back the amount loosened.

5. Rolate eccentric barrel until pro­per chain tension is achieved and se­cure three reta Ining nuts.

6. Install the chetncese cover andsecure with two retaining nuts. To in­sure cor rect placement of the coverseal, pos ition the seal on the case andthen install cover.

7. Set machine upr ight and check forleaks and proper ctt tever.

8. Re-install tuned pipe and muff lerassembly.

SUSPENSIONADJUSTMENTS

Three adjustments are provided withthe slider suspension to change han­dling and ride character istics depend­ing on snow condi tions and rider we ightand preference.

1. The rear spr ing tension can be ad­justed by means of the eye bo lt con­nect ing the spring 10 the swing arm. Anormal adjustment would provide onlyslight (Y.2 n) deflection (measured at therear of the chass is), with the driver inthe normal operating posit ion. For dou­ble rid ing or rough, cross-country ridingmore spr ing tension will be required.

2. The tension of the front leaf springscan be adj usted with the tapered shim.Install ing the shim between the springand the spring mount changes sl iderposition.

(a) With the thick side of the shim for­ward, slider load is Increased and skiload decreased. Acceleration and trac­tion will be Improved but decreased skiload will result in reduced turn ing abil­ity. Hill clim bing abilit y is also improved.

(b) With the thick sIde 01the shim rear­ward. corner ing abil ity will improve, ac­celeraton perfo rmance will decreasebut can be improved by an extreme aftr iding position. Hill cl imbing ability willdecrease due to less traction.

3. Slider suspension travel and chas­sis ground clearance are adjust able.Two adjus tab le screws limit the up­travel 01the slider system.

For racing or high performance require­ments several variations should be triedto provide the best performance for thespecific rider.

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SLIDER SUSPENSION

Proper track tension and alignment areessential to minimize wear 10 the dr ivecom ponents and track - also to maln­tain effic ient operation of Ihe snow­mobile. Check track tensIon frequently(every 20 miles) in the init ial 150 milesof operati on. Alter the track conformsto the suspension, check the tensionand alignment every 10 hours of opera­tion.

Adjust track tension as tollows:

1. l oosen the locking bolts on eachend 01secondary axle.

2. lay the sled over on its right sideso the track is nOl louchlng the ground.At the center of the slide rail, grasp agrauser bar with your index finger andpuilirack away from the slide rail ; thenadjust unt il distance betwee n inside oftrack and slide rail wear bar is 1 to 1Yzinch (both sides). Too loose a track willproduce 8 racheting noise during raploacceleration and should not be allowedto continue or damage to the track willresult. Adju stment Is made by tighten­ing the adjusting bolt to force the sec­ondary axle to the rear of the machine.

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Tighten unt il correct track tension is

atta ined.

3. Place rear of vehicle on suitableblocking to raise track off ground andblock fron t end for stability.

4. Before starting engine be suregrauser bars are securely fastened andthe tr ack is free of all fo reign objectswhich could be thr own out by the rnov­Ing tr ack.

5. Start engine and run tr ack slowlyfo r a minute or so, then tu rn eng ine ali.

6. With track stopped and rear of ve­hicle raised off the ground observe dis­tance between outside of rear Idlerwheel af!d Ins ide edge of internal drivelugs on each side. If lugs on one sideere closer to the idler wheel than thoseon the opposite side , an alignment ad­justment is necessary. An improperlyadjusted track will always run or dr ifttoward the LOOSE side, and this con­dition requires a track tension adjust­ment on the loose side only.

7. When correct track tension andalignment have been attained, retightenlocking nut retaining the secondaryaxle.

'"'' ALIl.iNMENT

The sk is have been properly aligned atthe factory and will not need furtheradjustment unteae the skIs or steeringhave rece ived a severe Impact. Skis areIn correct alig nment when they areparalle l to each othe r.

To correct alignment:

1. Tum the handlebar so it is level.

2. If steering Is out of adjustment,keep the handlebar level In the straigh t­ahead pos iti on.

3. Loosen lock nuts on steer ing ue­rod tube to be adjusted .

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4. Rotate tie rod adjuster to changetie-rod length as required to make theski s parallel.

5. Check to see that skis are parallelby measuring distance between skis atfr ont and rear.

6. Tighten the lock nuts.

7. 011 spind les periodically.

8. Uft front 01 machine off groundand check sleering for bind ing .

9. Check all lo ck nuts 10be sure theyare tight.

SKI WEAR BAR

A replaceable wear ba r (skeg, skeg) isfastened to the bottom of the ski toprevent sk i damage when runn ing overabrasive terrain and to aid In turning inherd-pecked snow cond it ions. Period icInspection is requi red so that worn wearbars are repla ced before skis are dam­aged and to mainta in good steering.

To replace wear bars on the bottom ofthe sk is. proceed as follows:

1. Tip the vehic le to one slce.

2. Remove the nuts and wear barstuds.

3. Insert the straight end of the newwear ba r in the fr ont sk i hole and alignthe stud holes In ski .

4. Replace the nuts and repeal pro­cess on the other ski .

THROTILE ADJUSTMENTThe throttle must be proper ly adjustedto preve nt stret ch ing of the cable, allowwide open thr ottle, and synchronizecarburetors so that both are ope n anequal amount at all l imes.

To adjust cable :

1. loosen elbow locking nut at car­buretor.

2. Hold thum b throttle open . Adjustthreading housing (at carb } lor maxt­mum thrott le as handle bar thumb throt­tle hits bottom then retighten elbowlocking nut.

3. Operate the hand lever 10 wideopen thrott le posi tio n, check the car­buretors lor wide open throttle travelwilhOut stretching the cable.

4. Be certain that you have free playin cable wit h thrott le released and bothcarbs are in synchronization.

CARB ADJUSTMENTAs the operator of a Nitro FI A you mustma inta in correc t car buret or ec lust­mente.

HIGH SPEED

Carburetors have a fixed high speed je twhich establi shes the min imum amountof fuel flow at high speed. To rtchenhig h speed luel mixture rotate plasticknob counter-c lockwise. To establi shcorrect sett ing start with richest sett ingand test run veh icle in an area whe refull thro tt le operation can be safelyused. If engine " blubbers" or "e-cyctes"stop engine and reset high speed ad­justment V. turn leaner . Test run unt ileng ine stops " 4-cycl lng". Check settingfrequently by "read ing " spark plug.

CAUTION; a too lean condition willcause serious engine damage.

IDLING

The idle ai r mixture screw (smallest ad­justi ng sc rew) Is cl osed or enri ched byturning clockwise and leaned or openedby turn ing counter-clockwise. After en­glne is warm adjust air mixture screw10 obta in best running condi tion, thenrlchen slightl y (turn clockwise) untilacceleration is withou t hesitation.

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Adjust idle speed screw (large knurledhead) on bo th carburetors so that throt ­tle opening is the same for bo th andeng ine idles at about 1200 RPM. If id le Isset too high choke becomes ine ffective.

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IGNITION SYSTEM

All models are equipped wi th a capac­ttor discharge ignition . Rupp 's CO Igni­tion contains no wear ing parts and isfactory preset. The super high energycharacte rist ics of the CD ignition vir·tua lly el iminates plug fouling and sparkplug- induced pre-Ignit ion. Normall y theonly owner maintenance required is tocheck and/or replace the surtace gapspark plug. The spark plug should berep laced when the distance from thel ip of the center electrode to thethreade d end of the plug Is 1/ 32 inch orgrealer or when it becomes oil fouled.Use Rupp part no. 25086 or ChampionN19V spark plug only.

WARNING: IGNITION VOLTAGE ISVERY HIGH. NEVER REMOVE INSULA·TORS WHILE SYSTEM IS IN OPERA­TION.

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TROUBLE SHOOTING

The foll oWing are the most commontroubles experienced and the probablecauses.

NOTE: lIems shown with an aSlerisk(")may be correc ted by ow ner. All othe rsmust be performed by an authorizedRupp dealer .

ENGINE FAILS TO START ORSTARTS WITH DIFFICULTY

• Kill or tether switch not in " run"pos ition

• Spark plug fou led or faul ly

• Engine ever-choked

· Water in fuel

• Obslucted luel line

• No tue l in tank

Loose or defect ive ignitionwiri ng /switch

Poor compression

Blown head casket

ENGINE Will NOT IDLE

• Faully spark plugIdle jel cl ogged

• Idle speed sett ing improper• Idle mixture setting imp roper

EXCESSIVE SMOKE

• Improper fuel mixture• Air intake blocked• Incorrect carbureto r adj ustment

ENGINE LACKS POWER

Carburetor d irty or damaged• Choke par tially closed

Ignit ion system malfun ctionLeaky head gasketWorn piston or ri ngs

• Track or drive system bind ingTorque convertor not func tioning

properly

ENGINE KNOCKS

Carbon In combustion chamberLoose fl ywheelLoose or worn connect ing rodWorn cylinder

• Fuel oc tane too lowImprope r ignition timing

ENGINE OVERHEATSCarbon in combustion chamberEngine improperl y timed

• Excessive load in engine• Improper fuel/oil mixt ure

ENGINE VIBRATES EXCESSIVELY• Associated equipment out of balance

Bent crankshaft• Engine not secu rely mounted

PERIODS OF POWER LOSS

• Fuel line clogged or kinked• Faulty ignition cable• Water in fuel system

STORAGEWhen the snowmobile is stored lakethe lollowing steps to protect it:

1. Remove fuel line from carburetorsand run the eng ine at idle until it stops.This uses up fuel in ca rbureto r. Allerengine stops. shut off Ignition switch .

2. Remove spark plug(s) and putapproxi mately two teaspoons of oilthrough the spark plug holes with pis­tons at " Top Dead Center." Crank theengine over 15 or 20 times with starter

and replace spark. plug. Use a goodquality anticor rosive oil.

NOTE: Repeat step NO.2 every 60 daysof storage.

3. Siphon fuel from tank.

4. Remove torqu e convertor belt .

5. The snowmo bile must be storedwith the track off the ground.

6. Cover machine and store in a dryplace to prevent rusting.

SET-UP INSTRUCTIONS1. Remove carton top and cut band

which secures chassis to skid.

2. Remove bolts which secure theski spindles to the carton skid and re­move the snowmobi le from the skid.Retain the bolts. washers and nuts forallaching skis.

3. SKIS- Remove skis from chassis.

4. T ip the snowmobile on one sideand align ski spring bracket hole withthe bushing installed in the ski spindle.

NOTE: Skis are right and left hand ;install with stops toward inside.

5. Install bolt through bracket, spi n­dle. shock absorber washer and securewith nut toward center of the snow­mobile. Torque bolt to 60 foot poundstorque.

6. Repeat steps 4 and 5 for oppositeski.

CHAI NCASE

Remove lett tuned pipe assembly. Tipsnowmobile on the right side. Removethe two nuts that retain chaincasecover. Check chain tension, re- installseal on edge of case, gently set coverin place. Chaincase cover Is pulled intoproper position when the two retain ingnuts are tightened down, do not pushcover onto chaincase. With snowmobileon level surface remove oi l fill plug andttutc bott om edge of fi Ji hole. Re-in stalltuned pipe and muffler assembly.

HANDLE BARWith the skis in a straight forward pes t­tion insert sptined steering shaft lntohandlebar mount and secure with spe­cia l locking bolt provided. CAUTION:BOLT MUST BE TIGHTENED TO 15FOOT POUNDS TORQUE.

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1975 NITRO FIASNOWMOBILE SPECIFICATIONS

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Install hand lebars in posit ion desiredand secu re with bo lts provided. CAU ­TION: TIGHTEN NUTS EVENLY TO 10FOOT POUNDS TORQUE .

STIRRUPS

StIrrups are inc luded and may be in­stalled at a position to sui t the rider.CAUTION : MAKE CERTAIN THEY AREINSTALLED IN SUCH A WAY THATTHE RIDERS FOOT REGARDLESS OFBOOT SIZE COME S FREE SHOULD HEBE THROW N FROM THE MACHINE.

WARRANTY

SERVICE POLICY AND WA RRANTYINFORMATION ARE COVER ED IN THES EPA RA T E " W A RRA NT Y FA CTSBOOKLET."

1975 NITRO F/ A

Engine v anutacturerEngine ModelDisplacement CCBore (mm)StrokeCarburetor MakeCarburetor Siz.eGas/Oil RalioStarting SystemIgnition TypeEngine TimingAlternator OutputHeadlamp WattageSpark Plug TypeCompressioo RatioNumber of CylindersTorque Converter Drive SystemVariable Drive RatioTrack Surface Bearing LengthOverall LengthHeight W/W indshleldTrack WidthSuspensionGas Tank CapacityType of Track Drive

340

RuppK34o-2RS33.6060Mikunl2/ 36 mm20:1RecoilCDI.095 BT DC150 Walt60/60Surface Gap7.0:12YeoYeo34.5"95.0"30.0"16-Slider3.2 GallonsInternal

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RuppK44Q.2RS429.•6760Mikuni2/38 mm2O:tRecoilCDI.095 8T DC150 Watt60/60Surface Gap7.0:12Yeoy"3• .5"95.0"30.0"16"Slider3.2 GallonsInternal

RUPPKLAWSSpi ke type tract ion studs with a chisel­shaped Kar b i d e poin t. La rg e 1 YB ~

square backing plate and T-shapedanchor nul anchor Kfaws 10 Ihe trac k.Avai lab le in package of 20. PN 36993

RUPPKROWNSKrown shaped traction stud s wi th fi ved igg ing points that attac k in all di rec ­tions for excellent cornering , stopping ,and acceleration. Healed treated 10 l ifesteel hardness, circfe design can't bendoul of shape. Rib head boll anchorsKrown tightly to the track . Spec ial lock­ing nul wit h star washer perma nentlyaff i xed g ives su re lock m ount ing .Krown your Rupp with a package of 20.PN 36992

SNOWMOBILE COVERSpec ial Rupp design, urethane coatednylon con struction . Each cover is cus­tom-fitted tor your part icul ar Auppmode l.

RUPP SUPER SYNTHETICLUBRICANT •A che mica l based lubr icanttor all out performance. Mixwith gasoline or alcohol fo rtwo-cycles or rep laces SAE20 Ihru SOW in the 4 st rokecrankcase. Virtually elimi­nates carbon build-up andplug fou ling . PN 33018

SLIDER ROLLER KITInc ludes bogg ie wheels and mount inghardwa re to add boggies to slide rail s.Lets you go in marginal snow . PN 37717

SPEEDOMETER/ODOMETERPrec ision made for more accurate read­ings. Gear redu cer, cab le and mount inghardwa re inc luded. PN 37728

KARBIDE SKI WEAR BARSGet the competitive edge . Wear barshost stay sharp karbide Inserts . He­places stand ard ski wear bar. PN 36991

TC SPRING KITThe kit consists of a selec tion of 4Torque Convertor Springs varied intension to allow you to set your TICengagement at a speed best suttee fo ryou r type of use. PN 32623

TC WEIGHT KITAn assortment 01 drive torque co nver ­tor wei ghts whic h can be used to obtainvariou s shifting pattern s. PN 37721

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