1975 Rupp Fa Nitro Owners Manual

lrK,l,,OnlyThe Best RIDERS MANUAL

Transcript of 1975 Rupp Fa Nitro Owners Manual

Page 1: 1975 Rupp Fa Nitro Owners Manual

lrK,l,,OnlyThe Best RIDERS MANUAL

Page 2: 1975 Rupp Fa Nitro Owners Manual


We are Dleased al the conlidence you have shown Inselecting a Rupp snowmobile from the many modelsavailable. Your Rupp snowmobile represents the f inestin engineering, design, and workmanship which aretradit ional at RUPP Industries.

We ask that you read this manual caretul ly so youwil l be able lo give your snowmobile the care andconsideration i t deserves. With such attention, you' l lenjoy al l the performance and durabil i ty buil t intoyour new Rupp machine. N'lake it a point to tamil iar-ize yourself with every phase of your snowmobile'soperation and care.

Your complete sat;staction is our goal Bupp dealersstand ready to help you wilh your mainlenance needs,repairs, parts or any help you may need.

Thank you for choosing RUPP.

"^._,*a. . : .

Page 3: 1975 Rupp Fa Nitro Owners Manual



Oporation Intormation

Safety Precaut iong . . . . . . . . . . . . . . . . . . . . . . . . . , 5


All htonatlon, lllu.tt.t16B.nd.P.ctttcattont aoh-t.tNc tn hb n.aul tt. bn.d ou.t lnr.mtie .r.tt.bl d h. th. ot tlbu6ttoa.fh. |k!hi ' fue.c|oMt. .n

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The 2-cycl6 a r cooled engine in yourRupp snowmobi le uses a gasol ino andoi l mixture lor luel . Use Rupp SuperSynlheiic Lub ricant o r a known brand ofSAE 40diluled 2-cycle {air cooled lype)engine ol l . GASOLINE TO OIL Mlx-TURE OF20TO 1 MUST BE USED, USEONLY PREMIUIV GRAOE GASOLINE',MINIMUM OCTANE 92. DO NOT USEWHITE GAS, NAPTHA. METHANOL,OR OTHER FUELS.


WARNII{G: Observe lire prevenlionrules. Mix luel ouldoors whenever pos-sible or in a wel l -vent i lated local ion.Putout al lc igarel tes and never mir luelnear an open l lame.


Thoroughly mix 1 quart ol oi l to l ive U.S.gal lons ol premium gasol ine in a cleancontainer. Measure gasol ine and oi l ac-curately. Pour aboul a gal lon of gaso-l ine inlo lhe conlainer i i rs l . Add thequartoJ oi land shake vigorously io mixthoroughly. Add the balance oJ gaso-l ine and mix again. At lemperatures be-low lree2ing, oi l does no! mix readi lywi lh gasol ine and exlra care must betaken to gel a good mixture,

Cleanl iness is importanl in mixingfuel. A smal l part ic le ol dir l can causecarburelor trouble. Always use lreshgasolne.

' Non-or low leaded gasol ines havenol been approved for 2-cycle engines.

Gum and varnish deposits lound in oldgasol ine may cause carburelor l roubleand spark plug loul ins. DO NOT POUROIL DIRECTLY JNTO THE SNOWIIO.BILE FUEL TANK.

Carburetor adiustments are sensitivelo tuel mixlure var iat ions which resultl rom use ol di l ferent gasol ine and oi lfal los due to inaccurale measuring olmixing, Be consislent. Prepare eachbalch ol fuelexacl ly lhe same as previ-ous one. Using more lhan the recom-rnended proporl ion ol oi l wi l l causeerrat ic carburet ion, excessive smokingand laster- lhan-normal carbon accu-mulat ioo. Using less oi l wi l l resul l indamage to the engine.Alter mixing, pour fuel into lhe snow-mobile tuel lank. Take care when lillinggas lank. Do nol spi l l Juel on the ma-chin€. WARNING: OO NOT FILL GASTANK WHILE ENGINE IS RUNNING OFHOTI

Spi l led gasol ine on a hot engine or ex-haust pipe wi l l create a f i re hazard,Avoid problems by al lowing the engineancl exhaust syslem lo cool down priorto adding gasol ine. Use a lunnel andpour careiul ly. Wipe up any spi l lage

Page 5: 1975 Rupp Fa Nitro Owners Manual

IGNITION/LIGHT SWITCHThe key switch on the dash controls al le leclr ical lunct ions oJ your snowmo-bi le. The "ol l " posi l ion gro!nds lheignit ion circui t and stops the motor.The headl ighl and lai l l ights are operated by turning lhe key to the ' l ights"posit ion with the motor running.

STEERINGSteering is conlrolled by lhe handle-bars. Turning the handlebars r ight orlel t wi l l turn the vehicle into the direc-tion ol lravel desired.

CHOKENilro F/A models have a choke lev€ron lhe dash (see illustralion). Place thechoke lever in "choke" position tor ichen fuel/air mixture Jor cold sta sand during ini l ia l warm up periods.Throltle must be closed {idle position)during choke operat ion. Choke wi l l noltunclion il throllle is open. Do notchoke a warm engine or " f looding" olth6 engine can occur,

KILL SWITCHThe ki l l switch on the handlebar con-t fols has three posi l ions. The centerposi l ion is the "run posi l ion. Theolher two posi l ions ground lhe igni t ionwhich slops lhe engine, Check posit ionot switch belore star l inq €ngine. USEKILL SWITCH TO STOP THE ENGINEIN AN EMERGENCY.




BRAKEThe brake control lever is at lhe letlhandgripon lhe handlebars. To operalebrake, squeeze lever wi lh f ingefs.WARNING: CHECK BRAKE CON-TROLS FOB PROPER OPERATION AE-FORE STARTING ENGINE.

THROTTLEThe throttle conlrol lever, or accelera-lor, is al tached lo lhe handgrip on ther ighlhand side oJ the handlebars. De-press the throltle l€ver to move thevehicle iorward and 10 increase speedand power, When the lever is released,engine speed wi l l rel l rn to idle. WAR -ING: CHECK THROTTLE CONTROLSTO AE SURE THFOTTLE RETURNS TOIOLE FREELY ANO NORMAL FORCETO OPERATE AOTH CARBURETORSIS FELT BEFORE STARTING ENGINE.NEVER START E NG INE WITHOUTFIRST CHECKING BRAKE ANDTHROTTLE CONTROLS.


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TETHER SWITCHTelher swilch is located in the cenlerof the dash, When the lether cord lspulled the switch kills" the engin€ andlhe lether cord "pops aparl To reselswitch to run position, push red sleeveon cord into swatch .eceplacle Wearthe black slrap suppl ied snugly aroundyour waisl . Attach lanyard clasp to D"r ing on strap. CAUTION: COMPLETELANYARD HOOK UP BEFORE START-ING ENGINE,

STARTINGThe starter handle is located on ther ight s ide of the engine This sta eris an automatic rewind tvpe and wi l lprovide many hours of t roublejree ser-vice by obseruing ihe proper slart ing

1. Be sLlre that fuel tank conlalns asuff ic ienl amount of properly mrxed

2. Be sure tether lanyard is hookedup to Your waislband

3. Check to see tha! tether and killswitch are in "run" Posit ion

4. Place choke lever in "oHOKE"posilion, turn the ignition kev to "ON"

NOrE: Choke only iunct ions whenthrol l le is in idle Posi l ion-


5. Grasp manual s lar l ing handlel i rmly and pul l outward slowlv unt i l en-gagemenl of ralchet mechanjsm can belel t . Then conl inue to pul l oulward wi lha vigorous stroke. Do not al low rope losnap back. Retain gr ip on handle andatlow rope 10 r€wind slowly. Do nol pullrope to end ol lravel. Relurn choke toopen posi l ion after lwo or three pul lsol manual starler or alter engine hast ired tr avoid engine f looding

6. Whsn engine slans, i l the chokelsst i l l on, return choke lever 10 "off"(normal running) posi l ion. l l enginelalters, actuate choke as needed, Donot use choke when star l ing a warmengine, or tlooding may occur.

7. DO NOT use or operale the auto-matic rewind starler while lhe engineis running, or damage may occur to lhe


l f , lor any reason, lhe rewind staf ler be_comes inoperative. lhe engine can besiarled via an ernergency slarter ropewhich shol ld be carr ied in tool box ai

1. Remove lour capscfews whlch se-cure rewind slar ier lo Jan hous ng, andremove complele rewind slarler hous-ing assembly-

2 Wjnd lenglh of rope around lheslarter sheave in a clockwise di fect ion,

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3. To start lhe engine, pul l lhe rop€wilh a vigorous stroke, lo l lowing theProcedure Previously out l ined.


SAFETY PRECAUTIONSYour Ni l ro F/A is a special ized highPerlormance machine and is not de-signed for the novice rider- DO NOTOPERAIE IHIS VEHICLE UNLESS


1. Always wear a helm€t and Jaceshie'd. The Nitro F/A is not equippedwilh a windshield and your lace shieldmust f€place its function.

2. Never start engine wathoul l i rsthooking telher switch cord to strap

3. Always check your lhrotllo andbrake conlrols AEFORE you lurn onlhe igni t ion key.

4. Never run engine with the lorqueconvener goard femovecl.

5. Obsefve al l ca!t ion decals on lhe

6. Neve. smoke while relueling orwhi le checking luel l€vel. Fuel gives ol lin l lammable vapors which can igni teinstanl ly wj lhoul warning. Instal l gas

7. Start each r ide with a tul l fuellank. Check luel supply every % hour.Always leave yoursell a salety rnargin.A snowmobile does nol travel lhe same

distance each time on th6 same amounlol tuel-

8. Do not overload your machin€.Your machin6 ia designed lor lhe diveronly. NO PASSENGEFS.

9. Always carry emergency mate-rials, extra spark plugs, torque conver-lor bel t , lools, kni te, and suppl ies. Ke6pyour Ownels Manual with the vehicle.

10. Jumping is fun but hard on themachjne. This lype of activity can putyou and your machine oUl of commis-sion for the ssason,

11. Oo not over-drive your brakes.Tesl braking distanc€s at var iousspeeds on the snow and ice condilionsin which you wi l l be operal ing.

12. lf you are planning to exptorenew areas, leave word wilh someon€oi your approximate whereabouts andesl imated l ime of return, Flemember, Asnowmobile can travet further in 15minules than you can walk in a day.

14, Do nol run snowmobite leanedoveror on a sland to cleaf hack, Flyingobjecls thrown lrom the lrack are ex-

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HEADLIGHT BULBREPLACEMENTThe headl ight has a replaceable bulb

1. Open shroud.

2. Headlight assembly is locaied onthe underside ol the shroud

3. L,nscrew plaslic cap to removeheadl ighl bulb and seal ing gasket

4. Unplug wir ing harness l rom bulband replace with new bulb.

5. When reinstal l ing socket in theheadl ight be sure the locai ing notch"l ines up.


The headl ight aim is adiustable- Fouradjustment screws are located in theJroni of the headl ight. Turn the scr€wsto move the headl ight beam in the de-sjred direct ion unl i l proper adjustment


The tai l l ight is a s ingle la i l /s top l ighlwi th replaceable bulb.

To replace a la i l l ight bulb:

1. Remove two screws relaining taiFl ight lens.

2. Remove the tai l l ighi lens by insert-ing a screwdriver belween the tai l l ightlens and housing and pry oft lens.

3, P! l l out delec ve bulb and replace.

4. Reassemble gasket and lens tohousing- Be sure "Top" of lens is at lopol body. Secure with screws.

Your snowmobi le is equipped with atachomeler with an i l luminat ing l ighl .

The lights have a push in type socket.The bulbs can be removed from thesocket by pushing in and lurning coun-



Page 9: 1975 Rupp Fa Nitro Owners Manual


The dr ive bel t is a v i ta l pad ol lhe dr ivemechanism. Frequent inspect ion ot thebelt is recommended and il il is loundlo be severely worn, replace as fo l lows:

1. Raise lhe cenler shroud, unlalchand raisebel tguard.

2. Apply brake lo prevent f ixed hal fof dr iven l lange from tufnlng. Rotatethe movable hal l of lhe dr iven l langeand push i t toward cenler ot vehlc le(compressing the spr ing). Then. s l idethe lorque conver ler bel l over the topol the movab e dr iven f lange.

3. Alter removing the belt lrom thedrven sheave. you can work i t o l f lhe

4. Instal l new bel l in reverse order.Do nol lorce or use lools to pry lhebel t Into place, as lh is could cut orbreak lhe cords in the bel t .

TOROUE CONVERTORThe torque conver lor does nol fequireany mainlenance other than per iodicl !bacat ion ol lhe shaf ls and rampsupon which ihe movable sheaves sl ideand f ywe ght pivol points ol the dr ivetorque conver ior cover. Use a smal lamount of graphi le base lo\ , ! lempera-

Excessive lubr icant wi l l ' throw of f"and cause bel i s l ippage. Torque con-vertor sheave al ignment should b€checked per jodical ly s ince misal ignmenl ol lhe torque conver lor sheaveswi l l cause premalure bel t fa i lure.

1. Remove the torque converlor bel t .

2. Place a slraightedge against lhemov€able dr iven f lange and us6lo seelhal the fixed drive llange is offsel 7,inch inboard and paral lel lo dr ivenl lange. Check al ignmenl al top andbol lom oJ dr iven l lange,

3. Al ign by loosening bolts that se-cure rubber engine rnounls and shif tengioe to correcl posi l ion. E€ cerlaindrive and draven llanges remain par-al lel . l l chain case is not perpendicularshim by instal l ing washers belweenchain case and chassis,

4. The chain case brace has an ad-tuslable bracket lo control lwist andal ignment ol lh€ chain case. Loosenlock nut, lhen rotate bolt 10 obtain de-sired al ignment, lhen secure lock nul.

5. Check center dislance betweenlhe dr ive and dr iven clutch assemblies.Distance should be 2lo 2% inch€s foropl imum perlormance.

ll a lorque convertor sticks or operateserrat ical ly. i l may be necessary to dis-assemble and clean shalt and bearings.

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PERFORMANCEALTERNATESThe following adjuslments can bsmade on your machine to give il lhe"custom performance" you desife.

(a) The dr iven tofque conv€r lorspring is laclory set lor optimum per-lormance und€r most conditions. Whena machine is us€d with exha heavyload, deep snow, steep hills or lake iceit may become desirable to have yourdealer change the spring setting to pro-vide improved pedormance und€r yourrunning condit ions.

(b) Optional sprockets for higher orrow€r g€anng.

(c) Drive torqlre convertof springs,to change engagement RPM's and shilt-ing pattern.

CAUIION: The ebove modificalionsshould be perlofmed only by a con-petsnt snowmobile mechanic. Be certain changes wi l l not cause lhe engin€

(d) For best p6rformanc6, lhe 440F/A should operale at 8500 RPM, the34oal8750RPM.


SELF ADJUSTER BRAKEThis brake system will need little or nomainlenanc6. Check the bfake pucks(wear shoes) tor w€ar occasionally.

qualilied automatic lransmission oil orhigh qual j ty motorcycle chain Oi l sui l -able lor low lempefalures,

DRIVE CHAIN TENSIONTo check chain tension, rornove th€chain inspeclion firbber plug or coverand pfess on the side of the chain.Chain tenslon is correct when the chainas not so tighl as lo be preloaded, anda slight

'6" deflection (slack in chaln)

is noticeable when presslng on the

NOIE| OveFlighl tension on chaincan cause premalure wear onsprockets, bearings, and chaln. Toomuch slack in chain could caule chainto "jump ' te6lh on lhe sprockets, wilhsubsequent damage lo sprockels, chainandlor cheincase.

lf lhe chain lension is incorrecti

1. Remove lefl tuned pipe and muf'f lerassembly.

2- Tip the machine on the right sid6to prevent chaincase oil leakage whenthe cover is removed.

3. Remove the chaincase cov6r byremoving the two retaining nuts.

When lhe pucks afe worn thin, conlactyour Rupp dealer for replacement.

CHAINCASEThe lubr ical ion level in lhe chaincaseshould be checked periodically andchanqed at lhe end ol each season. Tocheck lhe chaincase oil, remove theoi l l i t l p lug with the machine on a levelsurlace. The oal should bs level withbottom ot the lill plug hole. Use Derron

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4. Loosen the three r€taining nuls se-

curino the eccentr ic barrel appro;r-

malei lwo complete tufns and lightly

lap bolts back lhe amoont looseneo'


Three adiuslments are provided wilhthe slider suspension to change han-dling and ride characleristics depend-ing on snow conditions and rider weighl

1. The rearspring t€nsion can be ad'iusted by means ol the eye bolt con-neciing lhe spring to the swing arm. Anormat adiustment would provide onlyslighl (l,6/') deflection (measured at therear o{ the chassis), wilh lhe driver inthe normal operat ing posit ion For dou-ble r iding or rough, cross-country r idingmore spf ing lension wi l l be required

2. Thetension of thefront l€al spr ingscan be adjusted wilh the lapered shim.Inslal l ing the shim belween the spr ingand ihe spr ing mounl changes sl ider

Posi l ion,

(a) Wilh lhe lhick side ol the shim lor-ward. stider load is incfeased and skiload decreased. Acceleration and lrac-lion will b€ improved bul decreased skiload will resutt in reduced lurning abil_i ty. Hi l lc l imbing abi l i ly isalso improved

{b) With the thick side ol the shim rear-ward, cornering ability will improve' ac-celeraton pedormance will decreasebut can be improved by an extreme aitr id ing posit ion. Hi l l c l imbing abi l i ty wi l ldecrease due to less Vaction

3. Slider suspension travel and chas-sis ground clearance are adjustableTwo edjustable screws limit the up_travel ot the slider system-

Foi racing or high pe ormance require-msnts severalvar iat ions should be lr i€dlo provido the best performance lor thesp€cif ic r ider.

5. Rotate eccentric barrsl unlil pro-

per chain tension is achi€ved and se-

cure three relalning nuts.

6. Instal l the chaincase cover and

secure with lwo retaining nuis To in-sure correct placement ol the coverseal, posilion the seal on lh€ case and

7- Set machine upright and checklorleaks and proPeroi l lev€1,

8. Re-imtall luned pipe and mulller

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Proper l rack tension and al ignment areessenl ial 1o minimize wear lo the dr ivecomponenls and track - also to ma n-tain el l ic ienl operat ion of lhe snow_mobi le. Check track tension trequent ly(every 20 mi les) in lhe ini t ia l 150 milesof operal ion. Af lef the i rack conformsto the suspension, check the tensronand al ignment every 10 houfs of opera-

Adjust t rack lension as fol lows:

1. Loosen lhe locking boTts on eachend of secondary axle.

2. Lay the sled over on its right sideso the track is not touching lhe ground.At the center of the sl ide rar l , grasp agrauser bar with your index f inger andpul l t rack away from the sl ide rai l i lhenadjust unt i l d istance between inside oftrack and sl ide rai lwear bar is 1 lo 1%inch (bolh sides). Too loose a l rack wi l lproduce a rachet inq noise during rapidaccelerat ion and should not be al lowedlo cont inue or damage to the track wi l lresult . Adjustment is made by t ighlen-ing the adjust ing bolt lo torce the sec_ondary axle to the rear of the machine.



Page 13: 1975 Rupp Fa Nitro Owners Manual

Tlghlen unlil correcl track tension ls


3. Place rear of vehicle on suitableblocking to raise track off ground ano

block front end for s labi l i ly

4. Before starting engine be sure

orauser bars are secu lely lastened andihe lrack is l ree of al l toreign obieclswhich could be thrown oul by lhe mov-

ing track.

5, Stad engine and run irack slowlyfor a minule or so then lurn englne on

6. With track stopped and rear of ve-

hicle raised off the ground ofrsewe ols-

tance beh/veen outside of rear idler

wheel and inside edge of internal dr ive

luqs on each sid€ l f l t rgs on one sidear; c loser to the idler wheel lhan those

on the opposite side an al ignment ad-iustment is necessary An impropenyadiusted track wi l l a lwavs run or dr i f ttoward the LOOSE side, and lhis con-dition requires a track iension adjusl-ment on the loose side only.

7, When correcl t rack tension andal ignmenl have been at lained, ret ightenlockinq nut relaining the secondary

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The ski3 have been property atign6d stlhe laclory and will not need turtheradiustoant unl€8s the skia or st€oringnave rec€tved a 36v6re impact. Sk13 areIn corroct alignment when th6y areParall€l to each other.

To cor16ct alignlnent:

'l . Turn the handlebar so it is tevet.2. ll sleering is out ot adjustm€nt,

keep th6 handlebar teve n lhe straioht_ah€ad p6ition.

3, LooS€n lock nuls on steering lie_rod tib€ to be adjusted.

4. Rolate tie rod adjusler to changetie-rod length €s r€quired io mat(e theskis parallel.

5. Check to see that skis ar6 para elby mea3uring dlstance between skis atfrcnt and rear.

6. Tighlen lhe tock nuts.

Z Oll spindl$ periodica y.

8. Lift front of machino olt groundend ch€ck steering for binding.

9. Check atl tock nuts lo be sure theyare tight.

To replace w6er bars on the bo[om ofthe skis, proceed as follows:

l. Tip the vohicle to one sid€.

2, Remove lhe nuts and weer barstud3.

3. Insert the skaight snd ot th6 newwear ber in the tront ski hots and alionthe slud hol6s in ski

4, Replace the nuts and repeat pro_cess on the other ski.


A replac€abte wsar bar (skag, skeg) istaslenect to the bottom ol ihe ski toprovent ski damag6 when running ovsrabrasiv€ lerrain and to aid in turning inherd-peaked snow condi ons, periodicinspectlOn is requlrcd so thatworn woarbars ar€ replaced b€for€ Skis are dem_aged and to malntein good steering.

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THROTTLE ADJUSTMENTThe thfottle musl be p.operly adjustedto prevent strelching or lhe cable, allowwide open throl l le, and synchronizecarburetors so that boih are open anequal amount at al l l imes.

To adjust cable:

1, Loosen elbow locking nut at car-

2. Hold thumb throl l le open. Adjusllhreading housing (at carb) {or maxi-mum lhrol l le as handle barthumb throt-l le hi ts bot lom lhen ret ighlen elbowlocking nut,

3. Operate lhe hand lever to wideopen lhrollle posalaon, check the car-buretors lor wide open lhrol l le travelwi lhout slretchlng lhe cable,

4. Be certain lhat you have lree playin cable with throttle released and bolhcarbs are in synchronizat ion.

CARB ADJUSTMENTAs lhe operalorof a Ni l ro F/Ayou mustmaintain correct carburelor adjust-


Carburetors have a fixed high speed jetwhich establishes lhe minimum amounlol tuel f low at high sp6ed. To f ichenhigh speed luel mixlure rolale plast icknob counter-clockwise. To establishcorrecl seiting starl with richest sellingand lest run vehicle in an area wherefull ihrotlle operation can be salelyused. l f engine "blubbers' or "4-cycles"stop engine and reset high speed ad-juslment % turn leaner. Test run unl i lengine stops "4-cycl ing". Check sel t ingf.equenlly by ?eading" spark plug.

CAUTION: a loo lean condit ion wi l lcause serious engine damage,


The idle air mixture screw (smallestad-jusiing screw) is closed or enriched byl !rning clockwise and l€aned or openedby iurning counter-clockwise. Alter en-gine is warm adjust air mixtufe scaewto obtain best running condilion, lhenrichen sl ighl ly ( iurn clockwise) unt i laccelerat ion is withoul hesi tat ion,

Adjust idle 6peed screw (large knurledhead)on bolh cafburetors so that throt-t le opening is the same for both andengine idles at about 1200 RPM.l f id le issetloo high choke becomes inefleclive-



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All models ar6 equipped wi ih a capac-i lor discharge igni t ion. Rupp s CD igni-lion conlains no wearing pans and islactory presei. The super high onergycharacter is l ics oJ lhe CD ignit ion vir-tual lyel iminales plug tout ing and sparkplug-induced pre- igni t ion. Normatty theonly owner maintenance required is locheck andlor replace the surlace gapspark plug. The spark plug shoutd ber€placed when the dislance kom ihet ip ot th€ center electrod€ lo thethreaded snd of lh€ plug is 1/32inch orgrealer or wh6n il bocomes oit touled,Use Rupp part no. 25086 or ChampionN19V spark plug only.



The fol lowing are the most commonlroubles experienced and the probable

NOTE: l tems shown with an aster isk{t)may be corrgcled by owner. All othersmust be performed by an aulhorizedRupp dealer.


' Ki l l of telhsr switch not in , . run ,


'Spark plug louled or lautty

' Engine ov€rchoked

' Obstucted luel l ine

'Nofuel intank

Loose or delective ignition

Poo. compression

Blown head caskel

ENGINE WILL I{OT IDLE' Faulty spark plug

ldle jel c logged' ld le speed set l ing improper' ldle mixture setting improper

EXCESSIVE SMOKE" lmproper fuel mixture'Air in lake blocked' Incorrecl carburetor adjustment

EI{GINE LACKS POWERCarburetor dirty or dahaged

' Choke partially closedlgni i ion system malJunct ionLeaky head gasketWorn piston or rings

' Tfack or dive system bindingTorque converlor not lunct ioning

ENGINE KNOCKSCarbon in combuslion chamber

Loose or worn connecting rod

' Fuel ociane too towlmproper igni t ion l jming


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ENGINE OVERHEATSCarbon in combust ion chamberEngine improperly t imed

' Excessive load in engins' lmproper luel /oi l mixlure

ENGINE VIARAIES EXCESSIVELY' Associated squipment oul of balance

Bent crankshaft' Engine not securelY mounted

PERIOOS OF POWER LOSS' Fuel l ine clogged or kinked' Faul ly igni l ion cable' Waler in luel system

STORAGEWhen lhe snowmobile is slored lakelhe tol lowing steps lo Prolecl i l :

1, Remove luel l ine l rom carburelorsand run the engine at id le unt i l i t s lops.This uses up luel in carburelor. Al lerengine slops, shut ol l igni l ion switch.

2. Bemove spark plug(s) and putapproximately two teaspoons ol oilthrough the spark plug holes with pis-tons al "Top Dead Center. Crank lheengine over 15 or 20 t imes with slarter

and replace spark plug. lJse a goodqual i ty anl icorrosive oi l .

NOTE; Repeat step No.2 every 60 days

3. Siphon J!el f rom iank.

4, Remove torque converlor belt.

5. The snowmobi le must be storedwilh the track oi l the ground.

6. Cover machine and slore in a dryplace lo prevent rust ing.

SET-UP INSTRUCTIONSL Bemove carlon top and cut band

which secures chassis lo skid-

2. Remove bolts which secure theski spindles lo th€ car lon skid and re-move lhe snowmobie l rom the skid.Retain lhe bolls, washers and nuts foral laching skls.

3. SKIS-Remove skis l rom chassis.

4. Tip lhe snowmobi le on one sideand al ign ski spr ing brackel hole withthe bushing insral led in the skispindte.

I IOTE: Skls are r ight and lef t handiinslal l wi th slops toward inside.

5. lnstal l bol t lhrough brack€t, sp;n-dle, shock absorber washer and securewith not loward center ol the snow-mobi le. Torque bol l lo 60 loot pounds

6. Repeat steps 4 and 5 for opposileski .

CHAINCASERemove left tuned pipe assembly. Tipsnowmobile on lhe right side. Refiovelhe lwo nuts that retain chaincasecover. Check chain tension, re-anslallseal on edge of cas€, g€nlly set coverin place- Chaincase cover is pulled intoproper posj l ion when lhe two retainingnuis are i ighlened down, do not pushcover onto chaincase. with snowmobileon levelsur lace remove oi l f i l lp lug andl i l l lo bottom edge of l i l l hole. R6-instal liuned pipe and muff ler assembly.

HANDLE BARWilh the skis in a slraight loruard posl-t ion inserl spl ined sleer ing shatt in lohandlebar mount and secure wath spe-cial locking bol i provided. CAUTIOI{:BOLT MUST AE TIGHTENED TO 15FOOT POUNDS TOROUE.


Page 18: 1975 Rupp Fa Nitro Owners Manual

1975 NITRO F/ASt{OWMOBILE SPECIFICATIONSInslall handlebars in Dosition desired

and secure with bolts provjded. CAU-TION: TIGHTEN NUTS EVENLY TO 10FOOT POUNDS TOROUE, 1975 r{ttEo F/A





€ngin6 Manulactur6r

EngineTif t ing

Torqus Converter Orive System

Track S!rlac€ B€arinq Length

Heighr w/windshisld



cDl.095 BT OC





2/38 mm201

cDl.095 AT OC



34,5/95.0"30.0,16',Slid€r3,2 Gal lons


Page 19: 1975 Rupp Fa Nitro Owners Manual

RUPP KLAWSSpike type vact ion studs with a chiselshaped Karbide poinl . Large 1%"square backing plate and T-shapedanchor nut anchor Klaws to the track.Available in package ol 20. PN 36993

RUPP KROWNSKrown shaped tract ion studs wi lh l ivedigging points fhat al tack in al l d irec-t ions for excel lent cornering, s lopping,and acceleration. Heated lreated lo Jilesleel hardness, c irc le desiqn can' t bendout ot shape. Rib head bolt anchorsKrown l ight ly lo thelrack. Special lock-ing nul with star washer permanentlyal f ixed gives sure lock mounl ing,Krown your Rupp with a package of20.PN 36992

SNOWMOBILE COVERSpecial Rupp design, urethane coatednylon conslrucl lon, Each cover is cus-tom-l i t ied for your padicular Bupp

RUPP SUPER SYNTHETILUBRICANTA chemical based lubr icantfor al l oul per lormance. Mixwith gasolane or alcohol torlwo-cycles or replaces SAE20 lhru 50W in the 4 strokecrankcase. Vir l !al ly el imi-nales carbon bui ld-up andplug foul ins. PN 33018

SLIDER ROLLER KITIncludes boggie wheels and mountinghardware to add boggies to slid€ rails.Lets you go in marginalsnow. PN 37717

SPEEDOMETER/ODOMETERPfecision made tor more accufal€ read-ings, Gear reducer, cable and mountinghardware included- PN 37728

KARBIDE SKI WEAR BARSGet lhe competitive edge. Wear barshost slay sharp karbide inserts. Re-places standard skiwear bar. PN 369S1

TC SPRING KITThe kit consisls of a seleclion ol 4Torque Convertor Springs varied intension to al low you to set your T/Cengagemenl al a speed best suited foryour type of use. PN 32623

TC WEIGHT KITAn assortment ol drive lorque conver-lor wejghls which can be used to obtainvarious shitling patterns. PN 37721



I rt,|&I



Page 20: 1975 Rupp Fa Nitro Owners Manual