YEimaha PERSONAL WATER VEHICLE

YAMAHAYAMAHA MOTOR CORPORATION U.S.A.

Marine Division6555 Katelia AvenueCypress, CA 90630

WAVEJAMMER AND WAVERUNNER (1987 AND 1988)NOTE: Metric fasteners are used throughout vehicle.

GeneralEngine Make .OwnEngine Type Two-Stroke;

Water-CooledHP/Rated Rpm 30/4500-5500Number of Cylinders 2Bore 72 mm

(2.84 in.)Stroke 61 mm

(2.40 in.)Displacement 496 cc

(30.3 cu. in.)Compression Ratio 7.0:1Engine Lubrication Pre-MixFuehOU Ratio .50:1Engine Oil Recommendation. .Yamalube or Two-Stroke;

BIA Certified TC-W

TUne-UpEngine Idle Speed. 1500 rpmSpark Plug:

NGK B7HSChampion L82CElectrode Gap 0.5-0.6 mm

(0.020-0.024 in.)Ignition:

Type CDITiriiing 9°-ll° @ 1000 rpm

18°-22° @ 3000 rpm25°-29° @ 5500 rpm

Carburetor:Make .MikuniModel BN34 DiaphragmBore Size 28 mm

(1.1 in.)Low Speed Needle Setting 9/16—1-1/16 TurnsHigh Speed Needle Setting 5/8—1-1/8 TUms

Sizes—CiearancesCylinder Out-of-Round Limit 0.05 mm

(0.002 in.)Cylinder Tkper limit 0.08 mm

(0.003 in.)Piston-to-Cylinder WaU

Clearance 0.060-0.065 mm(0.0024-0.0026 in.)

Piston Ring End Gap:Ibp 0.2-0.4 mm

(0.008-0.016 in.)Second 0.20-0.35 mm

(0.008-0.014 in.)

Sizes—Clearances (Cont.)Piston Ring Side Clearance:

Ibp 0.02-0.06 mm(0.0008-0.0024 in.)

Second 0.04-0.08 mm(0.0016-0.0032 in.)

Maximum Crankshaft Runout 0.03 mm(0.0012 in.)

Maximum Connecting Rod SmaUEnd Shake 2.0 mm

(0.08 in.)Maximum CyUnder Head Warp 0.1 mm

(0.004 in.)CapacitiesFuel Iknk:

WaveJammer 13 L(3.4 gal.)

WaveRunner 22 L(5.8 gal.)

Tightening TorquesCylinder Head Cap Screws 28 N m

(20 ft.-lbs.)Crankcase Cap Screws 28 N m

(20 ft.-lbs.)Exhaust Cover Cap Screws 8 N m

(71 in.-lbs.)Engine Mounting Cap Screws 17 N m

(12 ft.-lbs.)Flywheel 140 N-m

(103 ft.-lbs.)Spark Plug 20 N m

(14 ft.-lbs.)Drive Shaft Couplings 37 N-m

(27 ft.-lbs.)Jet Pump Mounting Cap Screws 34 N m

(24 ft.-lbs.)ImpeUer 18 N*m

(13 ft.-lbs.)Standard Screws:

5 mm 5 N*m(44 in.-lbs.)

6 mm .8 N m(71 in.-lbs.)

8 mm 18 N-m(13 ft.-lbs.)

10 mm 36 N-m(25 ft.-lbs.)

12 mm 43 N-m(31 ft.-lbs.)

118

SERVICE MANUAL Yamaha

LUBRICATION

All Models

The engine is lubricated by oUmixed with the fuel. Fuel:oU ratiosshould be 25:1 during break-in (firsttankful) of a new or rebuilt engine and50:1 for normal service when usingYamalube Two-Cycle Lubricant ForOutboards or a BIA certified two-stroke TC-W engine oil. Manufacturerrecommends no-lead automotivegasoline having a minimum octanerating of 84. GasoUne and oil shouldbe thoroughly mixed.

Grease intermediate housingthrough grease fitting (G—Fig. Y-32)with a water-resistant grease every sixmonths or more frequent if needed.

FUEL SYSTEM

Ali Models

CARBURETOR. Refer to Fig. Y-1 foran exploded view of Mikuni type BN34diaphragm carburetor used on allmodels. A choke plate (21—Fig. Y-1) isactuated by choke knob (K—Fig. Y-2 orFig. Y-3) on control panel via a cable andUnkage.

Initial setting of low speed mixtureneedle (22-Fig. Y-1) is 9/16-1-1/16 turnsout from a Ughtly seated position andhigh speed mixture needle (29) is 5/8 to1-1/8 turns out from a li^tly seatedposition. Final carburetor ac^ustmentsmust be made with engine at normaloperating temperature and running.Clockwise rotation of either needle

leans the mixture. Adjust low speedmixture needle (22) until smooth ac-celeration from the idle position isnoted. After adjusting low speed mix-ture needle, adjust idle speed screw(37—Fig. Y-4) untU engine idle speed isapproximately 1500 rpm with throttlelever completely released. Ib ac justhigh speed fuel:air mixture, the enginespark plugs must be removed and theirinsulator tip color noted.

NOTE: Make sure that fual tank contalnaa 50:1 fuel mixture.

Ffg. Y-2^Vl9w Idantmat focatfon of choka knob(K) on WinfaJammar,

Fig, Y-3—View Idantlfl&s location af choka knob(K) on W^rvaRunnar.

Ffg. Y-1—Exploded vfaw of MIkunf type BN34 diaphragm carburator uaad on all modala.1. Fuel inlet cover2. Gasket3. Inlet body4. Check valve diaphragm6. Gasket6. Pump body7. Diaphragm8. Gasket9. Gasket

10. Diaphragm cover

11. Gasket12. Regulating diaphragm13. Plate14. Diaphragm15. Gasket16. Inlet valve assy.17. Valve lever18. Pivot shaft19. Spring20. Choke shaft

21. Choke plate22. Low speed mixture

needle23. Washers24. Springs25. "O" rings26. Throttle shaft27. Throttle plate28. Body

29. High speed mixtureneedle

30. BaivJobolt31. Gaskets32. Return line fitting33. Spacers34. Bracket36. Cable lever36. Spring37. Idle screw

Ffg, Y-A—Vlaw Idantlflaa location of Idia apaadacraw (37).

119

Yamaha

Make sure cooUng system wiU receivean adequate supply of water, thenoperate and sustain engine at wide-open throttle for a suitable test period.Stop the engine with throttle in wide-open position. Remove spark plugs andnote insulator tip color. Normal in-sulator tip color is brown to Ught tan.If insulator tip appears to be Ught tanto white in color, then mixture is toolean and high speed mixture needle(29—Fig. Y-1) should be rotated outward(counterclockwise) VA turn to richenmixture. If insulator tip appears to bedark brown to black in color, then mix-ture is too rich and high speed mixtureneedle (29) should be rotated inward(clockwise) Vi tum to lean mixture.Clean, regap and reinstaU spark plugsand continue test procedures until sparkplug insulator tips are a normal color.

The fuel pump and regulatingdiaphragm (12) can be removed afterremoving the six through-bolts. Notethat aUgnment tabs on components (3through 12) are provided to assist inproper aUgnment during reassembly.

Do not remove choke plate, throttleplate or shafts unless necessary. Thechoke and throttle plate retainingscrews are either staked or retainedwith a thread locking solution to pre-vent loosening. If screws are removed.

. Y'5—Inlat naadia vahfa lavar ahould ba ffuahwfth ffoor of houaing racaaa aa ahown.

properly stake or apply a suitable threadlocking solution on threads prior toassembly. Inlet needle valve lever (17)must be flush with floor of housingrecess when needle valve is seated.Refer to Fig. Y-5. If lever must be ad-justed, push down on lever immediate-ly above spring to coUapse the spring,then bend the end which contacts nee-dle valve.

REED VALVES. Two vee type reedvalve assembUes (one for each cylinder)are located between the intake manifoldand crankcase. Remove intake manifoldfor access to reed valve assembUes.

Renew reeds if petals are broken,cracked, warped or bent. Do not at-tempt to bend or straighten reeds. Reedseating surface on reed blocks should besmooth and flat. Maximum aUowablereed petal stand open is 0.9 mm (0.04in.). Reed stop setting should be 6.0 mm(0.24 in.).

FUEL PUMP. The fuel pump is an in-tegral part of the carburetor. The fuelpump assembly can be overhauledwithout overhauling the completecarburetor.

With reference to Fig. Y-1, disassem-ble the fuel pump assembly. Inspect aUcomponents for excessive wear or anyother damage and renew if needed.Clean components as needed with asuitable cleaning solution. Blow drywith clean compressed air. If com-pressed air is not available, use only lint-free cloths to wipe dry. Make sure aUpassages are clear of any obstructions.

With reference to Fig. Y-1, reassemblethe fuel pump assembly with newgaskets. Securely tighten the sixthrough-bolts.

FUEL TANK AND FUEL FItrER. Afuel strainer assembly is attached on thebottom of '*0N'* fuel tank pickup Une(O—Fig. Y-6) and on the bottom of**RES" fuel tank pickup Une (R). An in-line fuel filter (I) is located between fuel

PERSONAL WATER VEHICLE

selector valve (V—Fig. Yl-7) and car-buretor fuel pump intake. PferiodicaUyunscrew cup on bottom of fuel fUter(I—Fig. Y-6) and withdraw seaUng ringand filter element from base. Clean cupand inspect filter element for excessivecontamination or damage. Renew seal-ing ring and any damaged components.Renew filter element if excessive con-tamination is noted. Reassembly isreverse order of disassembly. Fuel tankstrainers should not need to be removedand renewed unless contamination issuspected.

THROTTLE LEVER FREE PLAIT.Throttle lever should have 2-5 mm(0.08-0.20 in.) free play measured be-tween lever stop (S—Fig. Y-8) and endof throttle lever (L). Ib adjust, loosenlocknut (N) and rotate cable adjuster (A)untU the recommended free play is ob-tained. Tighten locknut (N) to retainadjustment.

FLAME ARRESTOR. Flame arrestor(F—Fig. Y-9) is located beneath cover(C). PeriodicaUy remove four screws re-taining cover (C) and withdraw coverand flame arrestor (F). Inspect flame ar-restor for contamination or damage andrenew if needed. When installing flamearrestor (F), make sure a tight seal isformed between mounting base andflame arrestor. Securely tighten the fourcap screws retaining cover (C).

Fig. Y-e~Vlaw Idantmaa '*ON" fual tank pickupHna (Oh ''RES" fual tank pickup Una (R) and In-

Una fual flltar (I),

IGNiTiON

Ail Modeis

AU models are equipped with asimultaneous capacitor discharge igni-tion system. The ignition timing is elec-tronically advanced as the magneto baseplate is fixed.

TROUBLE-SHOOTING. If ignitionmalfunction occurs, use only approvedprocedures to prevent damage to thecomponents. The fuel system should bechecked first to make certain that faul-ty running is not caused by incorrect

N A

Fig. Y-T—Viaw fual aalactor ¥at¥a (V).

S

Ffg, Y-a—Thmttla fmmr fraa play ahould ba 2-5 mm(0,08-a20 fn.) maaaurad batwaan lavar atop (S)and and of throttla favar (L). 7b adjuat, looaan

locknut (N} and rotata cabIa adfuatar (A),

120

SERVICE MANUAL Yamaha

I

mixture or contaminated fuel. Makesure malfunction is not due to sparkplug, wiring or wiring connectionfaUure. TVouble-shoot ignition circuit us-ing a suitable ohmmeter as foUows:

Separate the wires at the connectorsbetween magneto components and CDImodule. Refer to Fig. Y-U. Check con-dition of chaise coil (3) by attaching onetester lead to brown wire leading tomagneto assembly and attaching othertester lead to black wire leading tomagneto assembly. Charge coU can beconsidered satisfactory if resistancereading is within the Umits of 81-99ohms. Check condition of pulser coU (2)by attaching one tester lead to white/redwire leading to magneto assembly andattaching other tester lead to black wireleading to magneto assembly. Pulser coUcan be considered satisfactory ifresistance reading is within the Umits of92-112 ohms. Charge coU (3) and pulsercoU (2) are serviceable after removingflywheel cover and flywheel. Make surea suitable puUer is used to withdrawflywheel. Tighten flywheel nut to 140N-m (103 ft.-lbs.).

Tb check condition of ignition coU,separate the orange wire and black wireconnector at coil and remove high ten-sion wires from spark plugs. Attach onetester lead to terminal end of orangewire and other tester lead to terminalend of black wire. Primary coilresistance reading should be within thelimits of 0.12-0.18 ohms. Attach a testerlead to each high tension wire. Second-ary coil resistance reading should bewithin the Umits of 2800-4200 ohms.

If no components are found defectivein the previous tests and ignition

malfunction is stiU suspected, then in-staU a known good CDI module andrecheck engine operation.

CHARGiNG SYSTEM

Ail Models

AU models are equipped with alighting coil, rectifier/regulator, 20ampere fuse and battery. Standard bat-tery has a 19 ampere hour, 12 voltrating. The Ughting coU should produceat least 11.5 ac volts at 3000 rpm and13.5-16.5 ac volts at 5500 rpm. Rec-tifier/regulator assembly should regulatevoltage between 14.3-15.3 dc volts.

The battery electrolyte level should bechecked pedodicaUy and fiUed to max-imum level with distiUed water if re-quired. The battery should be removedfrom the vehicle and the battery capsremoved when charging. The manufac-turer recommends charging the batteryat a rate of 1.9 amperes for a period of10 hours. Do not exceed recommendedcharging rate.

NOTE: Make aure battery charging area Iswell ventilated.

The Ughting coU can be staticaUytested using a suitable ohmmeter. Referto Fig. Y-IL Separate two green wiresleading from lighting coil to rec-tifier/regulator assembly at connectors.Measure resistance between the two

T, To CDI ModuleTo Rectifier/Regulator

Fig. Y'11—Vlaw Idantffying magnato componantaand color of laada.

green wires leading to Ughting coU.Resistance reading should be 0.9-1.1ohms. Check for continuity betweeneach of the Ughting coil wires andground. Ifester should show infiniteresistance at each wire. Tb check rec-tifier/regulator assembly, refer to chartshown in Fig. Y-12. Tb check rec-tifier/regulator during operation, firstmake sure battery is fuUy charged,Ughting coU test good and aU wiring isin good condition and aU connectors fittightly or are securely fastened. Attacha suitable voltmeter directly to batteryterminals. Remove wash port plug (P—Fig. Y-13) located on top of exhaustguide plate. InstaU Yamaha flush kitABA-FLUSH-KT-01 (K-Fig. Y-14) or asuitable equivalent. Connect a sup-plemental water supply to flush kitinlet.

NOTE: Do not turn on water until enginela ready to be atarted aa exhaust floodingcould occur.

Start and run engine while observingvoltmeter. The voltmeter should show

\+Tester\Lead

-TesteALead \

Green1

Green2

Red

Black

Green1

\

A

D

B

Green2

A

\ ^

D

B

Red

B

B

\

E

Black

ccD

Fig, Y-12—Uaa chart ahown abo¥» and waluaaHatmdbalow^to taat condition of mctlflar/ragulator

aaaambly,A. 3,000 30,000 ohmsn I'SS^'^^'^ *'*''"' I*- Infinite resistanceC. 2,000-16,000 ohms E. 2,000-20,000 ohms

Fig, Y-9—Flama arraator (F} la locatad banaathcoyar (C),

1. Lighting coil2. Pulser coil3. Charge coilB. Black

G. GreenBr. Brown

W/R. White with redtracer

Fig. Y'13-Vlaw Idantmaa cooling ayatam w^hport plug (P) locatad on top of exhauat gulda plalaandfat pump cooling ayatam aupply hoaa (W).

121

Yamaha

approximately 14.3-15.3 dc volts. Makesure supplemental water supply isturned off at approximately same timeengine is stopped.

COOLiNG SYSTEM

Ali Modeis

AU models are water-cooled. Forcedwater is supplied to the engine by thejet pump. As jet pump impeUer rpm in-creases, so does water circulationthrough cooUng system.

Make sure jet pump water intake griU(G—Fig. Y-15) is kept clean. Inspect aUhoses periodicaUy for cracks, kinks orany other damage. The cooUng systemshould be flushed out after eachoperating period when vehicle is usedin contaminated or salt water. The cool-ing system should be flushed out priorto extended periods of storage and priorto usage after extended periods ofstorage.

Tb flush the cooUng system, removewash port plug (P—Fig. Y-13) located ontop of exhaust guide plate. InstaUYamaha flush kit ABA-FLUSH-KIT-01(K—Fig. Y-14) or a suitable equivalent.Connect a supplemental water supply toflush kit inlet. Use only clean, freshwater.

NOTE: Do not tum on water until engineIs ready to be started as exhaust floodingcould occur.

AUow water to circulate throughsystem for 10-15 minutes with engineoperating at fast idle. Make sure sup-plemental water supply is turned off atapproximately same time engine is stop-ped. If vehicle is to be stored for an ex-tended period, start the engine andoperate the throttle in quick bursts be-tween idle position and % throttle fora maximum of 10-15 seconds. AU waterremaining in exhaust system wiU beforced out, preventing damage fromdeveloping contaminates or freezing.

NOTE: Make sure engine Is not operatedwithout a supply of water longer than 10-15seconds or damage to engine and/or ex-haust components could result.

Spray clean, fresh water into jet pumpintake grUl (G) to wash contaminates orsalt from jet pump components.

PERSONAL WATER VEHICLE

cle huU. Note shims (S) located under Imounting plates and identify each shim Ifor instaUation in original location, dRemove any other components that wiU I

ENGINE

Ali Models

REMOVE AND REINSTALL. Discon-nect battery cables from battery andremove battery from vehicle. Rfemovethrottle cable and choke cable from car-buretor. Remove hoses from carburetorand label if needed. Remove the twocarburetor mounting nuts, thenwithdraw the carburetor. Cover intakemanifold passage to prevent entrance offoreign debris. Disconnect stop switchand starter switch from main enginewiring harness at connectors. RemovecooUng system supply hose (W—Fig.Y-17) and exhaust hose (H). Remove;drive coupler shield. Remove four capscrews (C) and washers retaining frontand rear engine mounting plates to vehi-

Flg. Y-15-^Mt pump watar Intaka grill (Q) fa kfcatadon t>ottom of hull.

Ffg. Y-14—Vlaw IdantlffaaYbmaha ffuah kit ABA-FLUSH-

KT-01 (IQ.

interfere with engine removal. Use asuitable Ufting device to hoist engineassembly from vehicle. Place engineassembly on a clean work bench.

Tb reinstaU, position Yamaha toolYW-6367, with stamped side facing up-ward, to underside of engine flywheelcover. Use a suitable adhesive to retainrubber mount damper in place. IfYamaha special tool is not avaUable, usea rubber damper 19.5 mm (0.77 in.) inthickness.

Use a suitable Ufting device to hoistengine assembly into vehicle. Make surecoupler is located between engine driveflange (E—Fig. Y-18) and intermediatehousing drive flange (I). A jackscrewhole is provided directly above eachengine mounting hole in front and rearengine mounting plates. InstaU shims(S—Fig. Y-17) into original locationa Laya straightedge across top of engine driveflange (E—Fig. Y-18) and intermediatehousing drive flange (I). Engine ddveflange (E) should be 0-0.6 mm (0-0.024in.) h i ^ e r (H) than intermediate drive

Ffg. Y-17—Vlaw kiantlfying cooling ayatam aupplyhoaa (W) and axhauat hoaa (H}, 7Wo cap acrawa(C) and waahara ara locatad on port and ataiboatdalda of vahfcia to rntafn front and raar anginamounting pfataa to vahlcia hull, f4ota ahlma (S)focatad undar mounting plataa and fdantify aach

ahIm for Inatallatlon In original locaUon.

Fig, Y'la—RaMr to taxt for maaaurfng hafght (H)and claamnca (C) batwaan angina drfva ffanga (E)

and Intermediate houaing drfym flanga (I).

122

SERVICE MANUAL

flange (I). Measure clearance betweenengine drive flange (E) and base of in-termediate housing drive flange (I).Clearance (C) should be 2-4 mm(0.079-0.157 in.). If recommended set-tings are not measured, then ac justjackscrews in front and rear enginemounting plates untU recommendedsettings are obtained. Then measureclearance between shim (S—Fig. Y-17)and engine mounting plate for requiredshim (S) thickness. Measure clearancefor all four engine mounts. InstaUrecommended shims and removejackscrews. Remove Yamaha toolYW-6367 or suitable equivalent. ApplyLoctite 242 or a suitable equivalent onthreads of four cap screws (C) andtighten cap screws to 17 N-m (12 ft.-lba).Remeasure as previously outUned toverify engine ddve flange to in-termediate housing drive flange settingsare as recommended. At^just shimthickness if needed.

Complete reassembly in reverse orderof disassembly.

DISASSEMBLY. Remove muffler, ex-haust guide plate outer and inner coversand exhaust guide plate. Engine driveflange and shaft are withdrawn with ex-haust guide plate. Remove flywheelcover, flywheel, magneto componentsand front oil seal housing. Remove elec-

I trie starter and overheat sensor (R—Fig.Y-19). Remove intake manifold, exhaustcover, exhaust inner plate and gaskets.Remove cyUnder head. Remove frontand rear engine mounting plates.Remove remaining crankcase cover capscrews, then separate crankcase coverfrom cyUnder block. Crankshaft andpiston assembly can now be removedfrom cyUnder block.

Engine components are now ready foroverhaul as outlined in the appropriatefollowing paragraphs. Refer to thefoUowing section for assembly pro-cedure.

ASSEMBLY. Refer to specific servicesections when assembUng the crank-

shaft, connecting rod and piston. Makesure aU joint and gasket surfaces areclean, free from nicks and burrs andhardened cement or carbon.

Whenever the engine is disassembled,it is recommended that aU gasket sur-faces and mating surfaces withoutgaskets be carefuUy checked for nicks,burrs and warped surfaces which mightinterfere with a tight seal. CyUnderhead, head end of cyUnder and matingsurfaces of crankcase should bechecked on a surface plate and lapped,if necessary, to provide a smooth sur-face. Do not remove any more metalthan is necessary.

When assembling engine, firstlubricate aU friction surfaces and bear-ings with engine oU. InstaU crankshaftassembly and make certain main bear-ing locating pins engage notches incyUnder block. Apply Yamaha GasketMaker or a suitable equivalent onmating surfaces of crankcase andcyUnder block, then position crankcasecover on cylinder block. InstaU frontand rear engine mounting plates withspacers. Spacers are located under capscrews (3,4, 5 and 6) as identified in Fig.Y-20. Apply Loctite PST Pipe Sealant ora suitable equivalent on threads ofcrankcase cap screws. Using tighteningsequence shown in Fig. Y-20, tighten thecrankcase-to-cyUnder block cap screwsflrst to 15 N-m (11 ft.-lba) then to a final

FlywheelEnd

Yamaha

torque of 28 Nm (20 ft.-lbs.). InstaUcyUnder head gasket and cyUnder head.Apply Loctite PST Pipe Sealant or asuitable equivalent on threads ofcyUnder head cap screws. Using tighten-ing sequence shown in Fig. Y-21, tightenthe cyUnder head cap screws to 15 N-m(11 ft.-lbs.) with the exception of capscrews (1, 5 and 9). Leave cap screws (1,5 and 9) loose untU muffler andoverheat sensor (R—Fig. Y-19) are in-stalled. InstaU exhaust cover, exhaust in-ner plate and gasketa Apply Loctite PSTPipe Sealant or a suitable equivsilent onthreads of exhaust cover cap sci ewa Us-ing tightening sequence shown in Fig.Y-22, tighten the exhaust cover capscrews first to 4 N m (3 ft.-lbs.) then toa final torque of 8 N-m (6 ft.-lbs.). Notethat cap screw (3—Fig. Y-22) is shorterthan all other exhaust cover cap screws.Apply Loctite 242 or a suitableequivalent on reed valve assemblymounting screws. InstaU Intake manifoldgasket and reed valve assemblies on in-take manifold. Apply Loctite PST PipeSealant or a suitable equivalent onthreads of intake manifold cap screwaTighten intake manifold cap screws to8 N-m (6 ft.-lba). Install front oU sealhousing. Apply Loctite PST Pipe Sealantor a suitable equivalent on threads ofcap screws retaining front oU seal hous-ing and securely tighten. InsUiU mag-neto assembly. IristaU starter motor and

14

Fig. Y-20-Tfghtan cnnkcaae cap acrawa fnquance ahown to torque speclffed In taxt,

7

6 13 12Fig. Y'22-Tlghtanaxhau9tcow9r cap acrwwafn aa-

quanca ahown to torque apeciffad tn taxt.

Fig, Y-IB—Vlaw Idantmaa location of angina oyar-haat aanaor (R),

Fig. Y-21—Tlghtan cyflndarhaad cap acrawa In aaquancaahown to torqua apa^Had In

taxt.

ThermostatEnd

123

Yamaha

apply Loctite PST Pipe Sealant or asuitable equivalent on threads of retain-ing cap screws and securely tighten. In-staU flywheel and tighten retaining nutto 140 N m (103 ft.-lba). InstaU flywheelcover and apply Loctite PST PipeSealant or a suitable equivalent onthreads of retaining cap screws andtighten M6 cap screws to 8 N-m (6 ft.-lba) and M8 cap screws to 18 N-m (13ft.-lba). InstaU engine drive flange andshaft with exhaust guide plate, outerand inner covers and related gaskets on-to engine. Apply Loctite PST PipeSealant or a suitable equivalent onthreads of mounting cap serein andtighten cap screws to 10 N-m (7 ft.-lba).InstaU overheat sensor (R—Fig. Y-19)and muffler assembly. lighten cyUnderhead mounting cap screws to 15 N m (11ft.-lba). Apply Loctite PST Pipe Sealantor a suitable equivalent on cap screwsretaining muffler to exhaust guide plateand tighten cap screws to 10 N m (7 ft.-lba). Using tightening sequence shownin Fig. Y-21, tighten the cylinder headcap screws to a final torque of 28 N-m(20 ft.-lba). Using tightening sequenceshown in Fig. Y-23, tighten the exhaustguide plate and exhaust guide plateouter cover cap screws to a flnal torqueof 20 N-m (14 ft.-lba).

PISTONS, PINS, RINGS ANDCYLINDERS. CyUnder bore should bemeasured in several different locationsto determine if an out-of-round ortapered condition exists. Cylinder out-of-round limit is 0.05 mm (0.002 in.) andtaper Umit is 0.08 mm (0.003 in.). Borecylinder to 0.50 mm (0.020 in.) oversizeif measured cylinder out-of-round ortaper is beyond limit. Inspect cylinderwaU for scoring. If minor scoring isnoted, cylinders should be honed tosmooth out cylinder wall.

II 09

Recommended piston skirt-to-cylinderclearance is 0.060-0.065 mm (0.0024-0.0026 in.). Recommended piston ringend gap is 0.2-0.4 mm (0.008-0.016 in.)for top ring and 0.20-0.35 mm (0.008-0.014 in.) for second ring. The recom-mended piston ring side clearance is0.02-0.06 mm (0.0008-0.0024 in.) for topring and 0.04-0.08 mm (0.0016-0.0032in.) for second ring. The top piston ringis semi-keystone shaped. Make surepiston rings properly aUgn with locatingpins in ring grooves.

When reassembUng, install new pistonpin retaining cUps (4—Fig. Y-24) andmake sure that **UP*' on dome of pistonis towards flywheel end of engine. Coatbearings, pistons, rings and cyUnderbores with engine oU during assembly.

PERSONAL WATER VEHICLE

CONNECTING RODS, CRANK-SHAFT AND BEARINGS. Thecrankshaft assembly should only bedisassembled if the necessary tools andexperience are avaUable to service thistype of crankshaft.

Maximum crankshaft runout meas-ured at bearing outer races withcrankshaft ends supported in lathecenteiB is 0.03 mm (0.0012 in.). Con-necting rod big end side clearanceshould be 0.15-0.65 mm (0.006-0.026in.). Side-to-side shake of connectingrod smaU end measured as shown in Fig.Y-25 should be a maximum of 2.0 mm(0.08 in.).

Crankshaft, connecting rods andcenter section components are availableonly as a unit assembly. Outer mainbearings (17 and 19-Fig. Y-24) areavaUable individuaUy.

Thirty-four needle bearings (7) areused in each connecting rod smaU end.RoUers can be held in place withpetroleum jeUy while instaUing piston.

Lubricate bearings, pistons, rings andcylinders with engine oU prior to in-stallation. Tighten crankcase andcyUnder head screws as outlined inASSEMBLSf section.

ELECTRIC STARTER

All Models

AU models are equipped with electricstarter shown in Fig. Y-27. Disassemblyis evident after inspection of unit andreference to exploded view. When serv-icing starter motor, scribe referencemarks across motor frame to aid inreassembly.

NOTE: An Impact driver should be usedto remove through-bolts (13). A thread lock-ing solution is placed on through-boltthreads at the factory.

Starter brushes have a standardlength of 17 mm (0.67 in.) and shouldbe renewed if worn to 13 mm (0.51 in.).

Fig. Y-23-Tlghtan axhauat gulda plata mkl ax-hauat guk^ plata outar covar cap acrawa In aa-

quanca ahown to foiqii* apacmad In fwrf.

Fig. Y-24—ExpkKtad vlaw of crankahaft aaaambly.1. Crank half2. Grazikpin U. Cktmiecting rod3. Itey 12. RoUer bearing4. Clip 13. Crank half6. Piston pin 14. Bearing A snap ring6. Thrust washer 16. Labyrinth seal7. Needle bearings 16. Snap ring8. Piston 17. Bearing9. Piston rin^i 18. "O" ring

10. Thrust washers 19. Bearing

Ffg. Y'25^^lde ahaka (A) at email end of con-necting rod ahould be a maximum of 2.0 mm (QJ)$

In.}.

124

SERVICE MANUAL

Commutator has a standard diameter of33 mm (1.30 in.) and should be renewedif worn to a diameter of 31 mm (1.22

j in.). Commutator undercut should be' 0.5-0.8 (0.02-0.03 in.). If undercut is 0.2mm (0.007 in.) or less, then use asuitable tool to remove the mica be-tween commutator sections untU under-cut between each section is within therecommended range. Apply a water-resistant grease to Up of seal in framehead (6). Apply a suitable thread lock-ing solution on threads of through-bolts(13) during reassembly. After reas-sembly, bench test starter motor beforeinstaUing on engine.

BILGE PUMP

Ali Modeis

When the vehicle is operated, the jetpump forces water through hose (T—Fig. Y-29) and past siphon hose (S) open-ing. The passing force of water creates

1^27—Explodad vfaw of typical alactrfc atartar."C" ring

, Stop3. Spring4. Drive6. "O" ring6. Frame head & seal7. "0*' ring

a vacuum effect, thus drawing (siphon-ing) any water out of vehicle bilge. Makesure aU hoses and strainer (R—Fig. Y-30)are kept clean of aU foreign debriaDisassemble and clean or renew com-ponents if needed. Make sure aU hoseconnections are tight or vacuum losswiU result in siphoning system malfunc-tion. An antisiphon loop is positioned atrear of engme to prevent water from be-ing drawn into huU when engine is notbeing operated.

ENGiNE DRiVE FLANGE

All Models

R&R AND OVERHAUL. Disconnectbattery cables from battery and removebattery from vehicle. Remove throttlecable and choke cable from carburetor.Remove hoses from carburetor and labelif needed. Remove the two carburetormounting nuts, then withdraw the car-buretor. Cover intake manifold passageto prevent entrance of foreign debris.Disconnect stop switch and starterswitch from main engine wiring harnessat connectors. Remove cooUng systemsupply hose (W-Fig. Y-17) and exhausthose (H). Remove drive coupler shield.Remove four cap screws (C) and washersretaining front and rear engine mount-ing plates to vehicle huU. Note shims (S)located under mounting plates andidentify each shim for instaUation inoriginal location. Remove any othercomponents that wiU interfere withengine removal. Use a suitable liftingdevice to hoist engine assembly fromvehicle. Place engine assembly on aclean work bench.

Remove exhaust guide plate outer andinner covers and exhaust guide plate.Engine drive flange (E—Fig. Y-18) andshaft are withdrawn with exhaust guideplate. Place flange drive shaft into asuitable soft-jawed vise and use Ifkmahatool YW-6365 with a suitable tool torotate drive flange off shaft. Withdrawshaft out rear of exhaust guide plate. In-

Yamaha

spect aU components for excessive wearor any other damage and renew if need-ed. Renew exhaust guide plate shaft sealduring reassembly. Apply a water-resistant grease on flange drive shaft,bearing and seal. Apply Loctite PSTPipe Sealant or a suitable equivalent onthreads of flange drive shaft. Placeshaft with assembled components intoa suitable soft-jawed vise. Screw driveflange onto threaded shaft and useYamaha tool YW-6365 with a suitabletorque wrench and tighten drive flangeto 37 N m (27 ft.-lba). InstaU enginedrive flange and shaft with exhaustguide plate, outer and inner covers andrelated gaskets onto engine. Apply Loc-tite PST Pipe Sealant or a suitableequivalent on threads of mounting capscrews. Using tightening sequenceshown in Fig. Y-23, tighten the exhaustguide plate and exhaust guide plateouter cover cap screws first to a torqueof 10 N m (7 ft.-lba), then to a final tor-que of 20 N m (14 ft.-lbs.).

Ib reinstaU engine, position Yamahatool YW-6367, with stamped side facingupward, to underside of engineflywheel cover. Use a suitable adhesiveto retain rubber mount damper in place.If Yamaha special tool is not avaUable,use a rubber damper 19.5 mm (0.77 in.)in thickness.

Ffg, Y-30-Vlaw Idantmaa bllga atmlnar (R),

Fig. Y-29—Tha Jat pumpfofcaa watar through hoaa (T)and paat bllga afphon hoaa(S) opaning whan tha vahlcfa

laoparatad.

8. Thrust washers9. Armature

10. Frame11. Brush assy.12. End housing13. Through-bolt

125

Yamaha

Use a suitable Ufting device to hoistengine assembly into vehicle. Make surecoupler is located between engine driveflange (E—Fig. Y-18) and intermediatehousing drive flange (I). A jackscrewhole is provided directly above eachengine mounting hole in front and rearengine mounting plates. InstaU shims(S—Fig. Y-17) into originsd locations. Laya straightedge across top of engine driveflange (E—Fig. Y-18) and intermediatehousing drive flange (I). Engine driveflange (E) should be 0-0.6 mm (0-0.024in.) h i ^ e r (H) than intermediate driveflange (I). Measure clearance betweenengine drive flange (E) and base of in-termediate housing drive flange (I).Clearance (C) should be 2-4 mm(0.079-0.157 in.). If recommended set-tings are not measured, then acljustjackscrews in front and rear enginemounting plates until recommendedsettings are obtained. Then measureclearance between shim (S—Fig. Y-17)and engine mounting plate for requiredshim (S) thickness. Measure clearancefor sdl four engine mounts. InstaUrecommended shims and removejackscrews. Remove Yamaha toolYW-6367 or suitable equivalent. ApplyLoctite 242 or a suitable equivalent onthreads of four cap screws (C) andtighten cap screws to 17 N m (12 ft.-lba).Remeasure as previously outlined toverify engine drive flange to in-termediate housing drive flange settingsare as recommended. Adjust shimthickness if needed.

Complete reassembly in reverse orderof disassembly.

iNTERMEDiATE HOUSiNGAND DRiVE FLANGE

All Models

R&R AND OVERHAUL. Disconnectbattery cables from battery and removebattery from vehicle. Remove throttlecable and choke cable from carburetor.Remove hoses from carburetor and labelif needed. Remove the two carburetormounting nuts, then withdraw the car-buretor. Cover intake manifold passageto prevent entrance of foreign debris.Disconnect stop switch and starterswitch from main engine wiring harnessat connectors. Remove cooUng systemsupply hose (W—Fig. Y-17) and exhausthose (H). Remove drive coupler shield.Remove four cap screws (C) and washersretaining front and rear engine mount-ing plates to vehicle huU. Note shims (S)located under mounting plates andidentify each shim for instaUation inoriginal location. Remove any othercomponents that wiU interfere withengine removal. Use a suitable Uftingdevice to hoist engine assembly from

vehicle. Place engine assembly on aclean work bench.

Remove intermediate housing (I—Fig.Y-32) three mounting cap screws.Withdraw intermediate housing withdrive flange. Position Yamaha toolYW-6355 in a vise with spUned-end andshaft fadng upward. Place intermediatehousing assembly on Yamaha toolYW-6355 with drive flange facing up-ward. Use Yamaha tool YW-6365 with asuitable tool to rotate drive flange offshaft. Remove oU seal housing capscrews (S) and withdraw oil seal hous-ing with oU seal and **0'* ring. Pressshaft out front of intermediate housing.Inspect aU components for excessivewear or any other damage and renew ifneeded. Renew aU seals and " 0 " ringsduring reassembly. Press shaft withbearings into intermediate housing fromfront of housing. Apply Loctite 242 ora suitable equivalent on threads of oUseal housing cap screws (S) and secure-ly tighten. Screw drive flange ontothreaded shaft and use Yamaha toolsYW-6355 and YW-6365 with a suitabletorque wrench and tighten drive flangeto 37 N-m (27 ft.-lba). Apply Loctite 242or a suitable equivalent on threads of in-termediate housing mounting capscrews and securely tighten. Iiyect awater-resistant grease into intermediatehousing grease fitting (G).

Tb reinstaU engine, position Yamahatool YW-6367, with stamped side facingupward, to underside of engine fly-wheel cover. Use a suitable adhesive toretain rubber mount damper in place.If Yamaha special tool is not available,use a rubber damper 19.5 mm (0.77 in.)in thickness.

Use a suitable Ufting device to hoistengine assembly into vehicle. Make sure

PERSONAL WATER VEHICLE

coupler is located between engine driveflange (E—Fig. Y-18) and intermediatehousing drive flange (I). A jackscrewhole is provided directly above eachengine mounting hole in front and rearengine mounting plates. InstaU shims(S—Fig. Y-17) into original locationa Laya straightedge across top of engine driveflange (E—Fig. Y-18) and intermediatehousing drive flange (I). Engine driveflange (E) should be 0-0.6 mm (0-0.024in.) h i ^ e r (H) than intermediate driveflange (I). Measure clearance betweenengine drive flange (E) and base of in-termediate housing drive flange (I).Clearance (C) should be 2-4 mm(0.079-0.157 in.). If recommended set-tings are not measured, then adjustjackscrews in front and rear enginemounting plates until recommendedsettings are obtained. Then measureclearance between shim (S—Fig. Y-17)and engine mounting plate for requiredshim (S) thickness. Measure clearancefor ail four engine mounts. InstaUrecommended shims and removejackscrews. Remove Yamaha toolYW-6367 or suitable equivalent. ApplyLoctite 242 or a suitable equivalent onthreads of four cap screws (C) andtighten cap screws to 17 N m (12 ft.-lba).Remeasure as previously outUned toverify engine drive flange to in-termediate housing drive flange settingsare as recommended. Ac just shimthickness if needed.

Complete reassembly in reverse orderof disassembly.

Fig. Y-32~Qraaaa Intarmadfata houafng (I)through graaaa ffttfng (Q) wfth a marina typawatar-raalatant graaaa. Cap ecrawa (S) ratain oil

aaal houaing to fntarmadfata houaing.

JET PUMP

Ali Models

R&R AND OVERHAUL. Disconnectbattery cables from battery and removebattery from vehicle. Tum fuel controlvalve to **OFF" position and rotatevehicle on either side. Remove sixscrews retaining jet pump cover andlower cover to aUow access to hoseaRemove bilge siphon hose and jet pumpsupply hose from fittings on cover.Remove cooUng system supply hosefrom jet pump fitting. Detach steeringUnkage joint (L—Fig. Y-34) at baU jointon output nozzle. Remove four jet pumpmounting cap screws (C) (two at frontand two at rear) and four through-bolts(B) (two on top and two on bottom). Usea suitable tool and separate impeUerhousing from intake housing. Withdrawjet pump assembly with impeUer driveshaft out rear of vehicle.

Place Yamaha tool YB-6079 on im ipeUer drive shaft splines and position ina vise. Use a suitable tool and rotate im-peller clockwise to remove (impeUer hasleft-hand threads).

126

SERVICE MANUAL Yamaha

,mmmm, I ''**** •XTINOUISMSII 1

Fig, Y-34^Vlaw Idantmaa Jat pump mounting capacrawa (C) (two at front and two at rear), through-bolta (B) (two on top and two on bottom), outlat

noala (N) and ataerfng iinkaga joint (L),

Inspect impeUer drive shaft bearing inintake housing for excessive wear andfreedom of rotation. The intake hous-ing must be removed to service bearing.Remove cap screw on side of housingand withdraw spacer. Use Yamaha toolsYB-6229 and YB-6364 and drive bear-ing, washer and seals rearward into jetpump intake. Apply a water-resistantgrease on bearing and seal Ups, thendrive components into intake housingfrom jet pump intake side using Yamahatools YB-6229 and YW-6356. Securespacer with retaining cap screw.

Inspect impeUer and impeUer housingfor excessive wear or any other damage.ImpeUer drive shaft runout should notexceed 0.5 mm (0.02 in.) measured 371mm (14.6 in.) from front of shaft withimpeUer drive shaft supported in V-blocka Inspect all jet pump bearings forfreedom of rotation and damaged com-ponents. Inspect jet pump outlet bodyand intake housing for damage. Renewany seals that are damaged duringreassembly. Renew any other com-ponents that are excessively worn or arediagnosed with any other damage.

Apply Loctite PST Pipe Sealant or asuitable equivalent on impeUer threadsof impeUer shaft. InstaU impeUer onto

Fig. Y-36—Vlaw idantlfiaaataerfng cabia Iinkaga Joint(S) at ataaring ehaft iavar,Unkaga Joint ia iocated undertower accaaa cover on Wava-

Jammer modela.

impeUer drive shaft with original shim.Rotate impeUer counterclockwise andtighten to 18 N m (13 ft.-lbs.). ApplyYamabond 4 or a suitable equivalent onmating surfaces between outlet nozzle,outlet body, impeUer housing and intakehousing during assembly.

Measure impeUer blades clearance toimpeUer housing after assembly. Recom-mended clearance is 0.3 mm (0.012 in.).Add clearance measurement from allthree blades together, then divide thetotal by three to obtain the average forall three blades. If recommendedclearance is not measured, the shimthickness behind the impeUer must beadjusted to obtain optimum perform-ance. Increase shim thickness if averageof measured clearances is above 0.3 mm(0.012 in.) and decrease shim thicknessif average of measured clearances isbelow 0.3 mm (0.012 in.). Shims areavailable in thicknesses of 0.1 mm(0.004 in.), 0.3 mm (0.012 in.), 0.5 mm(0.020 in.) and 1.0 mm (0.040 in.). If re-quired shim thickness exceeds 5.1 mm(0.20 in.), then impeUer and impeUerhousing should be renewed.

ReinstaU jet pump assembly in reverseorder of removal. Apply Loctite PSTPipe Sealant or a suitable equivalent onthreads of four through-bolts (B) andsecurely tighten. Tighten four jet pumpmounting cap screws (C) to 34 N m (24

ft.-lba). Complete reassembly in reverseorder of disassembly. Apply a RTVsiUcone sealer around mounting surfaceof jet pump cover, then install cover andsecurely tighten six screws.

STEERING

All Models

ADJUSTMENT. When steeringhandlebar is rotated from side-to-side,there should be a minimum of 18 mm(0.71 in.) clearance between edge ofoutlet nozzle (N—Fig. Y-34) and eachside of huU. If not, remove steeringUnkage joint (S—Fig. Y-36) from baUjoint on steering shaft lever. If port sideclearance is greater than starboard side,rotate Unkage joint (S) outward on cable.If starboard side clearance is greaterthan port side, rotate linkage joint (S) in-ward on cable. Reattach steering Unkagejoint (S) on baU joint and recheck steer-ing clearance. Repeat acyustment pro-cedure if needed.

NOTE: If linkage Joint (S) must be rotatedout beyond the biack threaded area (8 mm[0.3 In.]) on cable, then linkage Joint (S) mustbe rotated inward beyond 8 mm (0 J In.) markand the remainder of the adjustment per-formed on Jet pump linkage Joint (L—Fig.Y-34).

127