Мануал ямаха браво 250

o YAMAHASNOWMOBILE

SERVICE MANUAl

LI1-12618-00-41 884-28197-10

FOREWORD

This Service Manual has been written to acquaint the mechanic with the dis­assembly, reassembly, maintenance, and troubleshooting procedures requiredto provide optimum performance and longevity of the machine.The information herein should be closely studied to avoid unnecessary repairsand to provide the owner with a sound, safe, dependable machine.

NOTE; _

The Research and Engineering Department of Yamaha is continually strivingto further perfect all models. Improvements and modifications are thereforeinevitable.In light of this fact, all specifications within this manual are subject to changewithout notice. Information regarding changes is forwarded to all AuthorizedYamaha Dealers as soon asavailable.

YAMAHA MOTOR CO., LTD.SERVICE DEPARTMENT

BR250FSERVICE MANUAL

© 1981 by Yamaha Motor Corporation, U.S.A.1st edition, June 1981

All rights reserved. Any reprinting orunauthorized use without the written

permission of Yamaha Motor Corporation,U.S.A. is expressly prohibited.

Printed in U.S.A.LIT-12618-00-41

Particularly important information is distingu ished in this manual by thefollowing notations:

NOTE:

WARNING:

A NOTE provides key information to make procedures easier orclearer.

A CAUTION indicates special procedures that must be followedto avoid damage to the machine.

A WARNING indicates special procedures that must be follow­ed to avoid injury to a machine operator or person inspectingor repairing the machine.

TABLE OF CONTENTS

GENERAL

ENGINE

CARBURETION

POWER TRAIN

CHASSIS

ELECTRICAL

APPENDIX

CHAPTER 1. GENERAL

1-1. EXTERNAL VIEW » 1-1

1-2. MACHINE IDENTIFICATION 1-2

1-3. TERMS 1-2

1-4. STORAGE 1-2

1-5. PRE-SEASON PREPARATION 1-2

1-6. MAINTENANCE 1-3A. Periodic Maintenance 1-3B. Lubrication Intervals 1-4C. Seali ng the Carbu retor. 1-5

1-7. HIGH ALTITUDE TUNING 1-5

1-8. SPECIAL TOOLS 1-6

1-1. EXTERNAL VIEW

GENERAL

1-1

1-2. MACHINE IDENTIFICATION 1-3. TERMS

A. Frame Serial NumberThe frame serial number is located on theright-hand side of frame (just below the frontof seat). The first three digits identify themodel. This is followed by a dash. Theremaining digits identify the productionnumber of the unit.

Grease:Unless other specified, use a low-tempera­ture lithium base grease when instructed togrease a part or component.

Thread-locking compound:Use Loctite® Lock N’ Seal (blue), unlessother wise specified, when applying athread-locking compound to securing hard­ware.

Oil:Use Yamalube 2 to oil components unlessanother oil is specified.

If a snowmobile will not be used for severalmonths, it should be stored in a proper placeso that both the engine and the track are notdamaged.

1. Completely drain the fuel tank, and dis­connect the fuel line from the carbure­tor.

2. With the engine running at idle, squirt oilinto the carburetor until the engine dies.This will distribute oil evenly throughoutthe engine and protect it against rust.

3. Disassemble the suspension, clean andgrease all parts, and reassemble thesuspension.

4. Lightly coat all shafts and axles withgrease.

5. Oil all fittings and wire controls with aIightly oiled cloth.

6. Loosen the track.7. Block the chassis so that the track is off

the floor.8. Protect the snowmobile with a covering.

1-4. STORAGE

1-5. PRE-SEASON PREPARATION

8R4-000101Starting frame serial number

B. Engine Serial NumberThe engine serial number is located on the fancase. The prefix indicates the engine type anddisplacement. The prefix is followed by adash and the serial number. Normally boththe frame and engine serial numbers areidentical.

Starting engine serial number R246-000101Perform the predelivery service as describedin the predelivery check list before operatingany snowmobile that has been stored forseveral months.

1-2

1~6. MAINTENANCE

A. Periodic MaintenancePerform the various inspections and services at the indicated intervals; however use this schedule asa guide only. Depending upon the operating conditions, certain components may require more fre­quent servicing.

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally400 km 800 km 1,600 km necessary(2

ENGINE:

Tighteness of bolts and nuts

Bends, cracks, and wear 0

Abnormal noise 0

Loose connection and breaks in the fuel and pulse pipes 0

Loose connection and breaks in the oil pipes 0

Loose connection and breaks in the oil delivery pipe 0

Recoil starter

Carburetor

• Operation of starter jet 0

• Mixing adjuster (pilot screw) 0

• Idle speed adjustment 0

Operation and adjustment of oil pump

Ignition timing 0

Cylinder compression 0

Cylinder/exhaust pipe decarbonize 0

Spark plug condition, gap, and cleaning 0

Tighten the cylinder** 0

DRIVE;

Tightness of bolts and nuts

Wear on slide runners 0

Primary drive system 0

V-belt ()

Secondary drive system 0

Sheave distance 0

Sheave offset =Brake pad wear 0

Brake operation and adjustment 0

Guide wheel rubber 0

Wear of track drive sprockets

Initial100 km

IDrive track adjustment (60mi) & 0300km(200mi) I

Breaks in drive track 0

Bends in front and rear axles 0 j

Check lock washers 0 !

Drive chain adjustment 0 iChain case oil level 0

** Retighten every 10 hours from the first use.

1-3

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or When Seasonally400 km 800 km 1,600 km necessary(250 mil (500 mil (1,000 rni]

CHASSIS:

Tightness of bolts and nuts 0

Bends and cracks 0

Welded riveted, joints 0

Ski adjustment 0

Ski runner wear 0

Breaks in fuel tank 0

Cleaning of fuel tank 0

Fuel filter 0

Loose connection and breaks in fuel pipe 0

Breaks in oil tank 0

Oil filter 0

ELECTRICAL:

Wear, breakage of wire covering 0

Breaks in high-tension cord 0

Voltage regulator output 0

Operation of engine stop switch 0

Operation of tether switch 0

Headlight 0

Taillight 0

Brake light 0

B. Lubrication Intervals

Every

Check point 20 hrs. or 40 hrs, or 80 hrs. or When Seasonallv Oil/Grease400 km 800 km 1,600 km necessary Brand name{250 mil (500 mil (1,000 mil

ENGINE:

Starter case 0

Oil pump control box 0 Aeroshell grease #7A or

Pump drive cover 0Esso Beacon 325 grease

Oil in the oil tank 0 YAMALUBE 2-cycle oil

DRIVE;

Primary sheave weights 0and roller pins Molybedenum disulfideSecondary shaft and 0

snowmobile greasesliding sheave

Front axle housing 0

Shaft 1 and shaft 2 Light all-purpose grease

(Slide rail) 0

Replace chain case oil 0 Gear oit API «GL-3″SAE #75 or #80

CHASSIS:

Steering column lower 0bearing Light all-purpose grease

Steering column upper 0bearing Motor oil

Steering links 0

Ski column 0

Ski wear plate 0Light all-purpose grease

Ski retaining pin 0

Brake cable end stopper0and brake lever Esso Beacon 325 gear

1-4

C. Sealing the CarburetorALWAYS seal the carburetor before turninga snowmobile on its side for service. This willprevent fuel from spilling and creating ahazard.

1. Plug the fuel-tank vent pipe.2. Plug both float-bowl overflow pipes or

connect them together.3. Drain float bowl.

1-7. HIGH ALTITUDE TUNING

To attain the best performance in high altitude conditions, carefully tune the snowmobile as out­lined below.

Confirm STD settings• Carburetor (Page3-3)• Ignition timing (Page6-2)• Spark plug (Page6-5)

+Adjust main jet size according to the chart

! (Page3-3)

Test main jet size(performance & plug colour) Not OK ~ Adjust main jet size(Page3-6)

•I I I

Not OK

Not OKOKI

OK

Check to see if gearing is too high or low

NotOK OKAdjust gearing as required(Page4-12)

OK Not OK

Not OK OKCheck engagement speed andshift performance

Not OK OK——r~High altitudetuning OK

Adjust primary clutch as required{Page4-1)

NotOK OK

Not 01<..Adjust secondary clutch as required{Page 4-1) OK

1-5

‘·8. SPECIAL TOOLS

7.

13.

&-b.

4-d.

4-b.

3.

1.

2.

No. Description Tool No.

1 Dial Gauge 90890..Q3097..Q0

2 Dial Gauge Stand 90890-01195-00

3 Dial Gauge Needle (56 rnml 90890-03098-00

4 3-Way Puller A’ssy TLU·90901-05-20 (U.S.A.)

4-a 3-Way Puller Attachment 90890-01803..Q0

4-b 3-Way Puller Attachment 90890-01804-00

4-c 3-Way Puller Screw 90890-01906-00

4-d Drive Handle 90890—1906-00

4-e 3-Way PuIler Body 90890..Q1848-00

4-f 3-Way Puller Attachment 90890..Q1873-00

5 Rotor Holding Tool 90890..Q1235..Q0

608 Primary Sheave Puller (M18) TLS-90018-59-02 (U.S.A_)

90890-01898..Q0

6-b Primary Sheave Puller Attachment 90890-01899..Q0

7 Primary SheaveSubassembly Tool TLS-9091 0-60-00

90890-01858-00

8 Bushing Tool 90890..Q1883..Q0

9 SheaveGauge TLS-9091 0-47-02 (U.S.A.)

90890-01702..Q0

10 Pocket Tester 90890..Q3112-00

11 Electro Tester 90890..Q3021-00

12 AC Regulator Checker 90890..Q3090-00

13 Primary Sheave Holder TLS·90018-80..Q0 (U.S.A,)

90890..Q1701-00

14 Secondary Sheave Holder 90890..Q1872-00

1-6

CHAPTER 2. ENGINE

2-1. ENGINE REMOVAL 2-1

2-2. DISASSEMBLY AND INSPECTION 2-2A. Recoil Starter 2-2B. Flywheel Magneto 2-3C. Oil Pump 2-4D. Top End 2-6E. Bottom End 2-10

2-3. ASSEMBLY AND ADJUSTMENT 2-12A. Bottom End 2-12B. Top End 2-13C. Flywheel Magneto 2-14D. Recoil Starter 2-15E. Oil Pump Gear Case 2-17

2-4. ENGINE INSTALLATION 2-19

ENGINE

2-1. ENGINE REMOVAL

You do not have to remove the engine inorder to service the following components:

Cylinder,Piston,Recoil Starter,Flywheel Magneto, andCarburetor

To remove the engine, remove or disconnectthe following components in the order givenbelow.

1. Muffler.2. Drive guard, V-belt, and primary sheave

(Refer 4-3, A «Removal.»)

3. Carburetor (Refer to 3-1, A «Removal.»)4. D-handle from the starter rope. Knot the

rope so it will not be pulled into thestarter case.

5. Spark plug wire.6. Pulse pipe from the fuel pump.7. Oil line that feeds the autolube pump.

Disconnect the joint in the middle of theline. Do not let air enter the line.

8. Four flywheel magneto leads.9. Hood Iimiter cable.

10. Three engine mounts; remove the engine.

2-1

2-2. DISASSEMBLY AND INSPECTION

A. Recoil Starter

Drive Plate Spring

Drive Pawl

Drive Plate

//

1. Remove the air shroud and the starterfrom the engine.

2. Pull about four inches of starter ropefrom the cutout in the sheave drum.Rotate the sheave drum five times clock- .wise to release the preload on the starterspring.

3. Remove the securing nut, and carefullydisassemble the starter. Note the relativeposition of each piece. You will have toreassemble the starter as shown in theillustration above.

Be careful when removing the drive plate andthe sheave drum. There is a preloaded springbehind each of these items.

2·2

B. Flywheel Magneto

Flywheel Magneto

Fan

1. Using the rotor holding tool, loosen thesecuring nut, and remove the flywheelpulley from the magneto.

1. Rotor Holding Tool: 90890-01235

2. Remove the six securing bolts and re­move the fan.

3. Using the 3-way puller, remove themagneto.

2-3

3-Way Puller Ass’y: TLU-90901-05-20 (U.S.A.)

1. 3-Way Puller: 90890-018482. 3-Way Puller Attachment: 90890-018033. 3-Way Puller Attachment: 90890-018044. 3-Way Puller Screw: 90890-019065. Drive handle: 90890-01817

4. Remove the woodruff key from thecrankshaft. Remove the two securingscrews and remove the coil plate.

5. For inspection, refer to 6-1, G «Pulserand Charge Coil.»,

C. Oil Pump

Plunger

Adjusting Pulley

1. Loosen the four gear-case bolts, andremove the gear case/oil pump assemblyfrom the engine.

2. Remove the two gear case screws andopen the gear case.

3. Remove the snap ring and the twowashers, and remove the drive gear. Notethe relative positions of the washer. Thewave washer is against the drive gear.

4. Rotate the oil-pump drive shaft until thesecuring pin is opposite the slot in thegear case. Remove the pin and removethe pump from the gear case.

~@~Oil Pump Drive Shaft

~

5. Remove the drive shaft from the oilpump. Inspect the bearing surfaces ofthe shaft and the gear teeth. If any partof the shaft is worn or pitted, the shaftmust be replaced.

The oil pump should not be disas­sembled unless the pump stroke must bechecked. If a problem with the pump isnoted (such as excessive oil consump­tion) proceed as follows:

6. Remove the oil pump cover.

2·4

7. Check the minimum pump stroke.a. Turn the oil pump gear until the plunger

is at its maximum distance from thepump body.

b. Using a feeler gauge, measure the gapbetween the adjusting plate and theraised bosson the adjusting puIley.

Minimum pump stroke:

0.2′» 0.25 mm (0.08′» 0.010 in)

1. Oil pump gear 2. Plunger 3. Minimum pump stroke

8. Measure the maximum pump stroke.a. Pull the oil pump cable out of its sheath

as far as it will go. The cable must beheld in this taut position when measur­ing maximum pump stroke. It may behelpful to securely wrap duct tapearound the cable where it enters thesheath.

b. Turn the oil pump gear until the plungeris at its maximum distance from thepump body.

c. Using a feeler gauge, measure the gapbetween the adjusting plate and theraised bosson the adjusting pulley.

Maximum pump stroke:1.65 — 1.87 mm (0.065′» 0.074 in)

1. Oil pump gear 2. Plunger 3. Maximum pump stroke 2-5

9. If either the maximum pump stroke orthe minimum pump stroke does notequal specification, remove the adjustingplate and add or remove adjusting shimsas required. Adding shims increases thestroke, removing shims decreases thestroke.

1. Adjusting shim

1O. Reinstall the adjusting plate and locknut. Torque the nut to specification.Recheck maximum and minimum pumpstroke.

Tightening torque:0.67 m-kg (4.8 ft-lb)

11. Grease the adjusting plate, and reinstallthe oil pump cover. Seal the cover withYamabond 5. Torque the screws tospecification.

Tightening torque:0.2 m-kg (1.45 ft-Ib)

… Denotes a revision. Please remove and destroy the original page, and insert this revision page in its place.

D. Top EndThis model has a one-piece cylinder andcyl inder-head assembly. There is no cylinderhead to remove and service separately fromthe cyl inder.

Cylinder

Disassembly1. Loosen the spark plug, and remove the

cyl inder from the crankcase.2. Cover the crankcase with a clean rag so

nothing will accidently drop into thecrankcase.

3. Remove a piston pin cIip from the… piston, and remove the pin with the

universal piston-pin puller.

Universal piston-pin puller:YU-01304

MS623 BR250F Service Manual Revised 1/82

2-6

~ Cvlinder Bolt

Piston Pin CI ip

4. Remove the piston and the small-endbearing from the connecting rod.

Inspection1. Piston pin and bearing inspection.a. Check the piston pin for signs of wear.

If any wear is evident, replace the pinand the bearing.

b. Check the pin and bearing for signs ofheat discoloration. If excessive (indenta­tion on pin, etc.), replace the pin and thebearing.

c. Check the small-end bearing for exces­sive wear or damage. Check the rollersfor signs of flat spots. If such wear isfound, replace the pin and the bearing.

d. Apply a light film of oil to the pin andbearing surfaces. Install them in theconnecting rod small end to inspect forwear. Check for play. There should beno noticeable vertical play. If play exists,check the connecting rod small end forwear. Replace pin, connecting rod and/or bearing, as required.

2-7

e. The piston pin should have no noticeablefree play in the piston. If the piston pinis loose, replace the pin and/or piston.

2. Pistona. Remove the piston rings.b. Remove any carbon deposits from piston

crown.

c. Carefully remove any carbon depositsfrom the ring grooves.

d. Hernove score marks and lacquerdeposits from the sides of the pistonusing 600 — 800 grit wet sandpaper.Sand in a crisscross pattern. Do not sandexcessively.

e. Wash the piston in solvent, and dry itwith compressed air.

f. Measure the outside diameter of thepiston at the piston skirt.The measurement shouId be made at apoint 10 mm (0.39 in) above the bottom

edge of the piston. Place the micrometerat a right angle to the piston pin.The maximum piston diameter subtract­ed from the minimum cylinder diametergives the piston clearance. If the clear­ance is beyond tolerance, hone thecylinder to tolerance or bore it to thenext oversize and install an oversizedpiston.

Piston clearance:

Minimum 0.045 mm (0.0018 in)Maximum 0.050 mm (0.0020 in)

Piston oversize:

70.25 mm (2.766 in)70.50 mm (2.776 in)

1. 10 mm (0.39 in)

2-8

3. Piston ringsa. Check the rings for scoring. If any severe

scratches are noticed, replace the rings as

a set.b. Measure the ring end gap in the un­

installed rings. If it is beyond tolerance,replace the rings as a set.

Ring end gap, free:Approx. 6.5 mm (0.26 in)

c. Push the ring into the cylinder, andmeasure the ring end gap with a feelergauge. Push the ring into the cylinderwith the piston crown so the ring will beat a right angle to the cylinder bore. Ifthe end gap is not within specification,replace the rings as a set.

Ring end gap, installed:Minimum 0.20 mm (0.0079 in)Maximum 0040 mm (0.0157 in)

4. Cylindera. Remove all carbon deposits from the

cylinder and from the ports. Carburetorcleaner will help lift carbon from thecyl inder head. Thoroughly wash thecylinder in solvent, and blow it dry withcompressed air.

b. Inspect the cylinder walls for scratches.If vertical scratches are evident, thecylinder should be rebored or replaced.

c. Measure the cylinder wall wear at theplaces shown in the illustration; use acyl inder bore gauge. If wear is excessive,compression pressure will decrease; re­bore or replace the cylinder.

———-Standard Wear limit

Cylinder bore70.00 ……, 70.02 mm 70.05 mm(2.756 -2.757 in) (2.776 in)

Cylinder taper 0.05mm(0.002 in)

Cylinder out-of- 0.01 mmround

-(0.004 in)

«~-‘-,,~~~

……. ——_…-….,…….,.,..

BoringIf the cylinder requires boring, follow thestandard boring procedures but use an offsetbit as shown below. This bit is standardequipment with some boring bars. Be surethat the depth adjustment is precisely set sothe combustion chamber is not damaged.

HoningWhenever honing the cylinder on the BR250,use a hone with a bumper device so the com­bustion chamber will not be carelesslydamaged. Otherwise follow standard honingprocedures. Yamaha recommends the use ofan Ammco Hone. This kit includes all thenecessary piecesto properly hone the cylinderon the BR250.

Ammco Hone Kit: TLU-03950-00-00

E. Bottom End

Oil-Pump Drive Sprocket

Engine Mounting Bracket

~@ ae~o~ ..

Right Crankshaft aearing~@ i

Disassembly1. Remove the engine mounting bracket

from the crankcase.

2. Remove the four crankcase bolts. Notethe position of the wire bracket. Youwill have to reinstall it on the same bolt.

3. Separate the crankcase halves by rappingthe indicated points with a rubbermallet.

4. Remove the crankshaft.

Inspection1. Crankcasea. Thoroughly wash the case halves in a

mild solvent. Blow them dry with com­pressed air.

b. Thoroughly clean the crankcase matingsurfaces.

c. Visually inspect the case halves forcracks or damage.

d. Inspect the oil delivery passages in thetransfer ports for signs of blockage.

2. Bearings and oil sealsa. After cleaning and lubricating the bear­

ings, rotate the outer race with yourfinger. If rough spots are noticed, replacethe bearings.

b. Check the oil seal lips for damage orwear. Replace the seals as required.

b. Install bearings with their manufacturer’smarks or numbers facing outward. Theyshould be visible when intalled.

c. Install oil seals with their manufacturer’smarks also facing outward.

d. Always thoroughly lubricate bearingsand oil seals with the specified lubricantbefore installing them on the crankshaft.

4. Crankshafta. Check the connecting rod axial play at

the small end. This will indicate thecondition of the big-end bearing andcrankpin. If the rod axial play exceedsspecification, disassemble the crankshaftand check the connecting rod, crankpin,and big-end bearing. Replace any defec­tive or worn parts. Reassemble thecrankshaft, and recheck the rod axialplay.

Rod axial play:Maximum: 2.0 mm (0.079 in)

b. Check the connecting rod side clearanceat the big end. If it exceeds specification,disassemble the crankshaft and replaceany worn parts.

Rod side clearance

3. Bearing and oil seal installationa. When install ing or removing the left

crankshaft bearing or oil seal, remove theoil-pump drive sprocket. Replace it witha new one during installation.

2·11

Minimum

0.25 mm (0.010 in)

Maximum

0.75 mm (0.030 in)

2-3. ASSEMBLY AND ADJUSTMENT

Tightening torque:1.5 m-kg (10.8 ft-lb)

2. Thoroughly oil the bearing and the con­necting rod.

3. Apply Yamabond 4 to the mating sur­faces of the crankcase halves. Useenough Yamabond to completely sealthe crankcase. An air leak can lead tosevere engine damage.

4. Carefully fit the lower crankcase halfonto the upper half. The oils seals andthe bearings must be properly seated inboth crankcase halves. Place the wirebracket on the rear crankcase bolt asshown in the photograph. Torque thefou r crankcase bolts to specification.

5. Install the engine bracket onto thecrankcase. Torque the four bolts tospecification.

R/H

Right side

0.02 mm (0.0008 in)

80 mm (3.1 in)

Deflection tolerance

Left side

100 mm (3.9 in)

0.02 mm (0.0008 in)

LlH

c. Check the crankshaft assembly runoutwith a dial gauge. If the runout is notwithin specification, the crankshaft partsare not properly aligned. To correct thismisalignment, tap the flywheel with abrass hammer. Use a wedge if necessary.

A. Botton End1. Place the crankshaft in the upper crank­

case half. Be sure the lip of each oil sealand the nylon bearing support for theright crankshaft bearing are properlyseated in the crankcase. The open sideof the bearing support must face thefront of the engine.

Tightening torque:First 1.0 m-kg (7.2 ft-Ib)Final 2.5 m-kg (18 ft-Ib)

2-12

B. Top End

Cylinder

Small End Bearing

1. Install the piston rings as shown in theillustration.

Piston crown

////// / / /////(JUJ/J//J////

__’:1 ‘——..;;:0..,,-

‘l//7//7/////77//7//7//7//7

2-13

rCYlinder Bolt

)

Top

Piston ring

2nd

2. Add oil to the crankcase through the oilholes. Oil the connecting rod.

3. Cover the crankcase with a clean cloth sonothing will fall into the crankcase.

4. Oil the small-end bearing and install it inthe connecting rod.

5. Oil the connecting rod, and install thepiston. The arrow on the piston crownmust point to the front of the engine.

6. Oil the piston pin, and install it in thepiston. Be sure the piston pin clip iscorrectly seated in the groove.

C. Flywheel Magneto

7. Oil the piston, and install the cylinderonto the crankcase. Use a new cylindergasket. Torque the four cylinder bolts tospecification. You will need a 12 mmcrowfoot wrench.

Tightening torque:First: 2.0 m-kg (14.5 ft-lb)Final: 2.5 m-kg (18 ft-lb)

Flywheel Magneto

2-14

Coil Plate

Coil Plate DamperIIIIIIIII~

Fan

1. Feed the magneto leads through thehole in the crankcase, and secure thedamper in the case.

2. Install the coil plate onto the crankcase.Align the pry points on the plate withthe cutout in the crankcase. Apply athread-locking compound to both secur­ing screws.

3. Place the woodruff key in the crank­shaft, and install the flywheel magneto.The keyway in the magneto must alignwith the key in the crankshaft. Rap themagneto with a plastic mallet to seat iton the crankshaft.

4. Install the fan on the magneto. Thearrow on the fan must point to the key­way in the magneto. Torque the six boltsto specification.

Tightening torque:0.7 m-kg (5 ft-lb)

2-15

5. Install the flywheel pulley. The two cut­outs on the edge of the pulley must beopposite the holes in the fan. Torque thesecuring nut to specification.

Tightening torque:7.0 — 7.5 m-kg (51 — 54 ft-lb)

6. For timing adjustment (Refer to 6-1, C»Ignition Timing.»)

D. Recoil Starter

1. Hook the outer book of the starterspring around the post in the startercase. Carefully wind the spring counter­clockwise, and fit the spring into thecase. Thoroughly grease the spring afterinstallation.

2. Feed the starter rope into the sheavedru m, knot the end, and fit the knotinto the cutout in the sheave drum.

3. Wind the starter rope 2-1/4 timescounterclockwise around the sheavedrum. Insert the drum in the starter case.Be sure the inner hook on the starterspring hooks around the post on thesheave drum.

4. Install the drive pawl and the returnspring. Hook the spring around the firstpost on the sheave drum as shown in thephotograph.

2·16

5. Install the drive plate spring, springcollar, and the drive plate. Be sure thecutout in the drive plate fits over thepost on the drive pawl. Install the thrustwasher and torque the nut. Grease thepivot point of the drive pawl.

Tightening torque:1.3 m-kg (9.4 ft-Ib)

6. Pull about four inches of starter ropefrom out of the cutout in the sheavedrum and form a loop. Rotate the sheavedrum five times couterclockwise to pre­load the starter spring.

7. Check the starter. If it does not operatesmoothly, disassemble it, and reassembleit correctly.

8. Install the recoil starter onto the engine.Be sure the hood limiter bracket is onthe forward, upper bolt as shown in thephotograph.

9. Install the air shroud. Use a washer andlock washer with the screw that securesthe air shroud to the starter case. Applya thread-locking compound to the twobolts that thread into the engine. Torquethe bolts to specification.

E. Oil Pump Gear Case

Tightening torque:0.65 m-kg (4.7 ft-lb)

2-17

1. Place the washer on the oil pump driveshaft, and insert the drive shaft into theoil pump. Be sure the worm gear correct­ly engages the oil pump gear in thepump.

2. Secure the pump to the gear case. Use anew gasket. Apply Yamabond 4 to thegear case side of the gasket only.

3. Align the hole in the drive shaft with theslot in the gear case and install the secur­ing pin.

4. Thoroughly grease the outer edges of thedrive gear onto the oil pump drive shaft.Be su re the gear correctly engages thesecuring pin.

5. Secure the drive gear in place with thetwo washers and the snap ring. Be su rethe wave washer is against the drive gear.

6. Grease the edges of the drive gear, andinstall the gear case cover.

2-18

7. Install the oil pump gear box onto theengine. Be sure the drive gear correctlyengages the oil pump drive gear on thecrankshaft. Torque the four securingbolts to specification.

Tightening torque:0.68 m-kg (4.9 ft-lb)

Bleeding the Oil PumpThe oil pump must be bled whenever:

Any portion of the oil system has beendisconnected.The machine has been turned on its side.Whenever the oil tank has been runempty.During predelivery.

There are two methods for bleeding the pumpon this model. Either will work very well.

1. Loosen the bleed screw at the pump. Oilshould begin to flow through the line.Keep the bleed screw open until all airhas left the fuel Iine. Tighten the bleedscrew.

2. Start the engine and keep it running atidle. Pull the pump stroke wire all theway out to set the pump at maximumstroke. Keep the pump operating at fullstroke for about two minutes. This willbleed the air from the oil system.

2-4. ENGINE INSTALLATION

1. Place the engine in the chassis. Torquethe three engine mounts to specification.

Tightening torque:Bolt: 3.0 m-kg (22 tt-lb)Nut: 1.4 rn-kq (10 ft-lb]

2. Install or connect the following compo­nents in the order given below.• Primary Sheave, V-belt. and drive

guard (Refer to 4-4, D «Assembly»)• Carburetor (Refer to 3-1, A III nstal­

lation»)

• Pulse PipeOil line that feeds the oil pump

• Four magneto leads• D-handle to the starter rope• Spark plug and spark plug wire

Spark Plug Tightening Torque:2.5′» 3.0 m-kg (18′» 22 ft-lb)

• Muffler and hood limiter bracket.

2-19

CHAPTER 3. CARBURETION

3-1. CARBURETOR 3-1A. Removal 3-1B. Disassembly 3-2C. Inspection 3-2D. Assembly 3-2E. Installation 3-3

3-2. TUNING AND ADJUSTMENT 3-3A. Carburetor Tuning Data 3-3B. Starter Cable Adjustment 3-4C. Throttle Cable Adjustment 3-5D. Oil Pump Cable Adjustment 3-5E. Low Speed Tuning 3-5F. Mid-range and High Speed Tuning 3-6G. Troubleshooting 3-7

3-3. INTAKE 3-9

CARBURETION

3-1. CARBURETOR

Carburetor Assembly

oMain Jet cover—@

A. Removal1. Disconnect the pulse pipe, oil pump

cable, oil delivery pipe, throttle cable,and the starter cable. Be careful not tolose the rubber cap or coil spring fromthe starter cable.

3-1

~ Starter Jet

®

~

2. Loosen the clamp on the carburetorboot and remove the carburetor. Do notlose a spring from the air box boot.

B. Disassembly1. Carefully remove the jets, float, etc.

Never, however, disassemble the throttlevalve or the throttle shaft. The threadsof the throttle shaft have been crimpedso the screw will not come lose. Oncethe throttle valve is disassembled, it willbe very difficult to reassemble it correct­ly. The original characteristics of thiscarburetor will be difficult to reproduce,thus performance will be adverselyaffected.

2. Carefu Ily clean all parts. Blow the jetsand passages clear with compressed air.Use a soft brush to clean the outsidesurfaces so nothing will be scratched ordamaged. Do not use a wire or any suchobject to clear a jet. This will deform thejet and reduce performance.

3. Remove the carbon from the throttl-evalve and adjacent area. Take care not toscratch the throttle valve or bore.

C. Inspection1. Inspect all jets and passages. They must

be clear.2. Check the mating surfaces for wear.

Replace jets as required.3. Check the float valve for damage. If

either the float seat or float needle aredamaged, replace both parts.

4. Check the pilot screw for carbondeposits; check the threads for wear.Clean and replace the jet as required.

D. AssemblyUse new O-rings when assembling the carbure­tor. Thoroughly grease the contact surfaces ofthe throttle shaft. Be sure all moving parts inthe carbu retor operate smoothly.

1. Install the throttle stop screw with itsspring. For adjustment (Refer to 3-2, E»Low Speed Tuning».)

2. Install the main jet and the slow jet.3. Install the slow adjuster with its spring.

For adjustment (Refer to 3-2, E «LowSpeed Tuning».)

4. Install the clip onto the float needle.5. Hook the float needle clip onto the float

tang. Install the float, and insert thefloat needle into the float valve.

3-2

6. Measure the float level.a. Incline the carburetor approximately 20

or 30 degrees until the float valve justbarely closes. The float should be restingon the float needle, but not compressingthe spring.

b. Measure the distance from the carbure­tor body to the top of the float.

Float height:15 ± 2 mm (0.59 ± 0.08 in)

1. Float height

c. If the float height is not within specifica­tion, examine the valve seat and the floatneedle. If either is worn, replace themboth. If both are fine, adjust the floatheight by bending the tang on the float.

d. Reinstall the float and recheck the floatheight.

8. Reassemble the float.

9. Apply grease to the following areas sothey will not freeze:Throttle return spring,Throttle shaft,Both spaces between the throttle shaftand carburetor body,Throttle lock washer,E~c1ip, andThe wire holder attached to the throttlevalve.

E. Installation1. Install the carburetor in the engine. Be

sure the air box boot and the carburetorboot correctly engage the carburetor.Secure the clamp on the carbu retorboot, and carefully secure the air boxboot spring.

Do not overstrech the air box boot spring.The spring can be damaged and will have tobe replaced.

2. Attach the throttle cable, starter cable,oil pump cable, oil del ivery line, and thepulse pipe. Refer to the Cable RoutingDiagram in the appendix.

2. High altitude tuning

3-2. Tuning and AdjustmentThe carburetor is set at the factory to run attemperatures of 32° F to _4° F (0° to -20°C)at seal level. If the machine has to be operatedunder conditions other than specified above,the carburetor must be reset as required.Special care should be taken in carburetorsetting so that the piston will not be damagedor seized.

A. Carburetor Tuning Data1. Standard specification

Carburetor BD32·28/KEIHIN

1.0. Mark 8R401

Main jet #108

Slow adjuster (turn out) 1·1/4

Starter jet. #120

Slow jet #78

15 ± 2.0 mmFloat height (0.59 ± 0.08 in)

~ -30°C -20°C -100 e O°C 10°C 20

0 e(-22°F) (_4°F) (14°F) (32°F) (50°F) (68°F)

Altitude I I J I I I.. #105 It’

Seal level .. #108 ………-#112 …..

…. #105 …»» 600 m (200 tt) .. #108 …

…#102 ….»» 1200 m (4000 ft) .. #105 ..

«»»‘-‘#108 …… #102 ..

«» 1800 m (6000 ft) .. #105 …….—#108 …..

……#100….»» 2400 m (8000 ft] .. #102 …

«»»‘-#105 …»» 3000 m or more .. #100 It’

(10000 ft) .. #102 …

3·3

3. Fuel flow

High-speed tuning

Mid-range. I Full 0 en

~~rq~:=========1t1:t====n:~~:E!=::~Elt====tt===ll=!~ttj1~~~ 1/2 ——~~—_1\:-__t__+_I_______/.I—-_:_~……L—~__+_~~l_!_

rClosed 1!~Low speed tuning

1. Starter jet2. Throttle stop screw, pilot screw,

bypass, float level3. Slow jet4. Main jet

BR250 CARBURETOR (KEIHIN 8032·28)Fuel Flow Chart

ITotal fuel flow

t

B. Starter Cable AdjustmentPuII the starter cable outer tube upward, andadjust the free play between the outer tubeend and adjuster to specification by turningthe adjuster. After the adjustment, tightenthe lock nut and replace the rubber cap tokeep the lock nut free from dust and water.

NOTE:— _

Starter cable free play must be adjusted afterthe cable is correctly routed. (Refer to CableRouting Diagram.)

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

Idle 1/4 1/2 3/4 1/1

Throttle opening •

3A

-.-H__- Free play

1.5″‘2.5 mm (0.06″‘0.10 in)

1. Adjuster 2. Lock nut

1. Play 2. Adjusting screw 3. Lock nut

Free play between outer tube endand adjuster:

1.5′» 2.5 mm (0.06′» 0.10 in)

3. Lock the adjusting screw by tighteningthe nut.

C. Throttle Cable AdjustmentSet the throttle cable adjuster so that the freeplay between the throttle cable outer tubeend and adjuster equals specification whenthe throttle valve is closed (at idle).

Free play between outer tube endand adjuster:

0.5′» 1.0 mm (0.2 ‘» 0.4 in)

E. Low Speed TuningThe carburetor is built so that low speedtuning can be done by adjusting the slowadjuster and the throttle stop screw.

Always install air silencer before makingtuning adjustment. High performance tuningcannot be done without the silencer. Enginedamage may result from attempting to tunewithout the silencer installed.

Play: 25 ± 1 mm (1.00 ± 0.04 in)

NOTE: _

Always adjust the throttle cable BEFOR Eadjusting the oil pump cable.

2. Start the engine, and fully warm up theengine.

3. Adjust the throttle stop screw until theengine runs at 2,000′» 2,500 rpm.

Stardard pilot screw (turns out):1-1/4

1. Tighten the slow adjuster lightly, andback it out from its lightly seated posi­tion.

1. Slow adjuster

3. Play2. Lock nut

1. Loosen the lock nut on the oil pumpcable adjusting screw.

2. Pull up the cable to its limit, and turnthe adjusting screw until the free play ofthe outer cable is as specified below:

1. Adjuster

D. Oil Pump Cable Adjustment

3-5

4. Slowly loosen slow adjuster. As the slowadjuster is loosened, the mixture willbecome leaner and engine rpm will in­crease. Adjust the slow adjuster to attainthe highest posstble engine speed.

5. Finally, turn the throttle stop screwcounterclockwise so that the engine runsat 1,100 rpm.

Idle speed: 1,100 ± 100 rpm

1. Throttle stop screw

NOTE: _

If the engine shows poor performance in highelevations or in an extremely cold area orwhen it is suddenly accelerated or run at lowspeeds, proceed as follows:

a. Replace the slow jet according to operat­ing conditions.

Standard slow jet: # 78

F. Mid-range and High Speed TuningNo adjustment is normally required, butadjustment is sometimes necessary depending

on temperatures and/or altitude.Mid-range speed and high-speed tuning (from1/4 to full-throttle) can be done by adjustingthe main jet.

1. Run the engine at high speeds, and makesure the engine operates smoothly.

2. Check the spark plug. The main jetshould be adjusted on the basis of thefollowing table. (Refer to spark plugcolor samples.)

Standard main jet: # 108

Spark plug color

No.1 Good (Carburetor is turned properly.)

No.2Bad (Mixture is too rich.lReplace main jet with one-step small one.

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

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

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

Bad (Due to too lean a mixture, theengine knocks.)Check the piston for holes or seizu reo

No.5 Check the cooling system, gasoline octanerating, and ignition timing. After replac-ing the spark plug, tune the carburetoragain starting with low-speed tuning.

Bad (Due to lean a mixture, the sparkplug melts.]Check the piston for holes or seizure.

No.6Check the cool ing system, gasoline octanerating, and ignition timing. After replac-ing the spark plug with colder type, tunethe carburetor again starting with low-speed tuning.

1. Slow jet 2. Main jet

b. By repeating steps 1 to 5 above, adjustthe idle speed.

Idle speed: 1,100 ± 100 rpm

3-6

1. Main jet

G. Troubleshooting

WARNING:

Never remove the main jet cover bolt whilethe engine is hot. Fuel will flow out of thefloat chamber which could ignite and causedamage to the snowmobile and possible injuryto the mechanic.Place a rag under the carburetor so fuel doesnot spread. Place the main jet cover bolt in aclean place. Keep it away from fire. Afterassembling the carburetor, firmly tighten therubber joint screw. Make sure the throttleouter tube is in place and the throttle cablemoves smoothly. Clean the carburetor andallow it to dry.

Trouble Check point Remedy Adjustment

Hard starting Insufficient fuel Add gasoline

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

Fuel passage is clogged or Clean Parts other than carburetorfrozen • Clogged fuel tank air vent, clogg-

ed fuel filter, or clogged fuelpassage

Carburetor• Clogged or frozen air vent clogged

valve.• If water collects in float chamber,

clean.(Also check for ice.l

Overflow Correct

Poor idling Improper idling speed Tighten slow adjuster lightly, andadjustment check throttle opening. If incorrect,

(Relative troubles) • Slow adjuster Adjust idling speed back it out specification. Start the• Poor performance at low engine and turn slow adjuster in

speeds and out 1/4 turn each time. When• Poor acceleration the engine runs faster, back out• Slowresponse to throttle throttle stop screw so the engine• Engine tends to stall idles at specified speed.

• Throttle stop screw Adjust Tightened to much — Engine speedis higher.Backed out too much Enginedoes not idle.

Damaged slow adjuster Replace slow adjuster

Clogged bypass hole Clean

Clogged or loose slow jet Clean and retighten Remove slow jet, and blow it outwith compressed air.

Air leaking into carburetor Retighten band screwjoint

Defective starter valve seat Clean or replace

Overflow Correct

Poor performance at Clogged or loose slow jet Clean and retighten Remove slow jet, and blow it outmid-range speeds with compressed air.(Relative troubles)• Momentary slow response

to throttle• Poor acceleration Lean mixtures Overhaul carburetor

3-7

Trouble Check point Remedy Adjustment

Poor performance at Clogged air vent Clean I Remove the air vent pipe, andnormal speeds clean.(Relative troubles)

Clogged or loose main jet Clean and retighten Remove main jet, and blow it out• Excess fuel consumption• Poor acceleration

with compressed air.

Overflow Check float and float valveand clean

Poor performance at high Starter valve is left open Fully close valve Return starter lever to its homespeeds position.(Relative troubles)

Clogged air vent Remove and clean• Power loss• Poor acceleration Clogged or loose main jet Clean and retighten Remove main jet, and clean with

compressed air, then install.

Clogged fuel pipe Clean or replace

Dirty fuel tank Clean fuel tank

Air leaking into fuel line Check joint and retighten

Low fuel pump performance Repair pump or replace

Clogged fuel filter Replace

Clogged intake Check for ice, and remove

Abnormal combustion Lean mix tu res Clean carburetor and adjust

(Mainly backfire) Dirty carburetor Clean carburetor

Dirty or clogged fuel pipe Clean or replace fuel pipe

Overflow Clogged air vent Clean

(Relative troubles)Clogged float valve Disassemble and clean Clean while taking care not to

• Power idling scratch valve seat.• Poor performance at low,

mid-range, and high Scraehed or unevenly worn Clean or replace float valve Valve seat is press-fitted to body.

speeds float valve or valve seat and valve seat So body must be replaced if seat is

• Excessive fuel consump- damaged.

tion Broken float Replace float• Hard starting

Incorrect float level If not within the specified• Power loss• Poor acceleration

range, check the followingparts and replace anydefective part.

• Worn float tang Replace float Replace float assembly.

• Worn pin Replace arm pin

• Deformed float arm Replace float

3-3. INTAKE

Carburetor Boot

Air Box Boot

Pulse Pipe

1. Check to see that fuel moves from thefuel tank, to the fuel pump, then to thecarburetor. If fuel leaks, replace thecomponents as required.

2. Inspect the air box boot and the carbure­tor boot. Replace as necessary. Replacethe air box boot springs if either isfatigued.

3·9

CHAPTER 4. POWER TRAIN

4-1. SHEAVE ALIGNMENT 4-1

4-2. CLUTCH TUNING 4-1A. Clutch Setting Data 4-2B. Changing Clutch Engagement and Shift RPM 4-3

4-3. V-BELT 4-3A. Removal 4-3B. Inspection 4-3

4-4. PRIMARY SHEAVE , .4-4A. Removal 4-4B. Disassembly 4-5C. Inspection 4-5D. Assembly 4-6

4-5. SECONDARY SHEAVE 4-8A. Removal 4-8B. Inspection 4-9C. Assembly 4-9

4-6. CHAIN CASE 4-10A. Disassembly 4-11B. Inspection 4-11C. Gearing 4-12D. Assembly 4-12

4-7. BRAKE 4-14A. Disassembly 4-14B. Inspection 4-15C. Assembly 4-15D. Brake Adjustment 4-15

4-8. SLIDE RAIL SUSPENSION 4-16A. Removal 4-16B. Inspection 4-17C. Installation 4-18

4-9. DRIV E 4-19A. Removal 4-19B. Inspection 4-20C. Assembly 4-20D. Track Adjustment 4-20

POWER TRAIN

4-1. SHEAVE ALIGNMENT

1. Sheave distance: 2. Sheave offset:266 ±2 mm (10.47 ±O.OS in) 11 ± 3 mm (0.43 ± 0.12 in)

1. Using the sheave gauge, check the sheaveoffset. If the gauge does not contact theprimary and secondary sheaves at thefour indicated points, the sheave offset isincorrect.

2. Check the sheave center-to-centerdistance.

4-1

3. If either the center-to-center distance orthe offset is not within specification,check the engine mounts. If the enginehas been mounted correctly, the enginemounting bracket, the frame, or both arebent. Replace as required.

Sheave gauge: TLS-9091O-47-02 (U.S.A.)90890-01702

Center-to-center:266 ± 2 mm (10.47 ± 0.08 in)

Sheave offset:11 ± 3 mm (0.43 ± 0.12 in)

4-2. CLUTCH TUNING

The clutch may require tuning dependingupon the area of operation and the desiredhandling characteristics. The clutch can betuned by changing engagement & shiftingrpm.Clutch engagement rpm is defined as theengine speed where the machine first beginsto move from a complete stop.Shifting rpm is the engine speed when themachine passes a point 200 ~ 300 m (650 ~

1000 ft) from the starting position after themachine has been started at full-throttle froma dead stop.Normally, when a machine reaches shift rpm,the vehicle speed increases but the enginespeed remains nearly constant. Under un­favorable conditions, however (wet snow, icysnow, hills, or rough terrain), engine speedcan decrease after the engine has reachedshifting rpm.

Engine rpm

tClutchshifting rpm

Clutchengagement rpm

Good condition

Clutch shifting rpm

Clutch engagement rpm

t Engine rpm

Bad condition

, __ Travelled distanceStarting position 200″»» 300 m (650″»» 1,000 ft)

A. Clutch Setting Data

1———+—4Travelled distance

——Starting position 200′»‘-‘ 300 m (650″»» 1,000 tt)

S.T.D. spec. High altitude spec.

Engagement r.p.m. 3100 ± 200 +-

Shifting r.p.m, 5750 ± 50 +-

Parts No. 90501·50654 +-

Set weight 15 kg (33Ib) +-Primary spring

2.4 kg/mm (134 lb/in)Spring constant +-

Color None +-

Q’ty 8 p.c.s./unit +-Roller shim

Parts No. 90201~06727 +-

Twist angle 1600

+-Secondary spring

Color None +-

NOTE.·~ _

High altitude specifications apply to operation at an altitude of more than 1506 meters (4500 tt),

Since the clutch weights are secured in placeby the sheave cap bolts, the centrifugal forcethat can alter clutch characteristics comesfrom the weight of the lever on the spider. Toadjust clutch engagement and clutch shiftingrpm, add or remove roller shims from thespider as indicated by the chart ..Clutch shifting rpm can also be adjusted bychanging the preload on the secondary sheavespring: 1600 and 280 0

• 1600 is standard.

4-2

B. Changing Clutch Engagement and Shift RPM

~Clutch engagement r.p.m. Clutch shifting r.p.m,

Decrease Increase Decrease Increase

Centrifugal force of rollers Add shims Remove shims Add shims Remove shims

Torsion spring- — Decrease Increase

Secondary spring constant

Twist angle — — Smaller wind Greater wind

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

Length of V-Belt

1,099 mm (42.8 in)

Part No.

820-17641-00

3. Measu re the length of the V-belt. Itshould be within specification; if not,replace the belt.

Wear limit: 26 mm (1.02 in)

4-3. V-BELT

A. Removal1. Turn the secondary sliding sheave clock­

wise and push it towards the cha in case.2. While holding the sliding sheave in this

compressed position, remove the V-beltfrom the secondary sheave then from theprimary.

B. Inspection1. Visually inspect the V-belt for signs of

damage. Replace the belt if it isdamaged.

2. Measure the width of the V-belt. If thebelt is worn beyond the wear limit,replace it.

1. V-belt length

4-3

4-4. PRIMARY SHEAVE

Fixed Sheave

Bushing

Sheave Cap

Bushing

Spider

Spider Lever

A. Removal1. Remove the drive guard, and remove the

V-belt,2. Hold the fixed sheave with the primary

sheave holder and remove the clutchbolt. Drive the primary sheave off thecrankshaft with the primary sheavepuller.

Primary sheave holder:T L5-90018-80-00 (U.S. A.)9089Q..01701

Primary sheave pu lIer:90890-01898

1. Sheave holder2. Sheave puller

4-4

B. Disassembly

1. Install the sheave subassembly tool inthe primary sheave.

Primary sheave subassembly tool:90890-01858

1. Sheave sub-assembly tool

2. Loosen the six sheave-cap bolts.3. Remove the sheave subassembly tool,

and remove the sheave cap.

C. Inspection1. Inspect the tapered ends of the crank­

shaft and the primary fixed sheave forscartches. If either is severely scratched,replace it. If scratches are minor, burnishthe component with emery cloth.

2. Check the primary sheave cap bushingand the sliding sheave bushing for wear.If worn beyond tolerance, replace thebushing.Use the bushing tool if a bushing is diffi­cult to remove.

Bushing tool: 90890-01883

1. Bushing tool

4-5

r. Bushing clearance, limit

Small bushing Large bushing

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

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

3. Remove the sliding sheave from thefixed sheave, and remove the spider.

4. Measu re the wear on the slider buttons.If worn beyond specification, replace thebuttons.

Wear limit: 27.0 mm (1.06 in)

5. Inspect the slides in the sliding sheavefor scratches or other damage; replacethe sl iding sheave as required.

6. Disassemble and inspect the rollers;replace worn parts as necessary. Torquethe nut to specification during reassemb­ly.

Tightening torque: 1.0 m-kq (7 ft-lb)

4-6

7. Disassemble and inspect the spiderlevers; replace any worn parts. Reassem­ble the levers with new cotter pins.

8. Inspect the cams for wear; replace asnecessary.

9. Check the spring. Replace it if it isfatigued or damaged.

D. Assembly1. During assembly, grease the indicated

points, but take care to keep the otherindicated areas from grease.

+- X Free from grease+- Grease point

2. Install the bushing and the spider intothe sliding sheav’e. Be sure the bottonscorrectly engage the slider.

3. Thread the sliding sheave onto the fixedsheave.

4. Install the cams. Be sure they arecorrectly seated in the sliding sheave.

5. Install the spring and the sheave cap. Besure the /IX» on the sheave cap alignswith the JlX» on the sliding sheave.

6. Install the primary sheave subassemblytool and secure the sheave cap to thefixed sheave. The two long bolts mustalso secure the clutch cams in place.Torque all six bolts to specification.

Primary sheave subassembly tool:90890·01858

Tightening torque:

1.0 m-kq (7 ft-Ib)

7. Check the movement of the slidingsheave. If it is not smooth, disassemblethe primary sheave and reassemble itcorrectly.

4-7

8. Clean the tapered portions of crankshaftand fixed sheave.

9. Fit the fixed sheave to the tapered por­tion of crankshaft.

10. Apply engine oil to the threaded portionof primary sheave bolt and its contactsu rface with spri ng washer.

11. Hold the primary fixed sheave with theprimary sheave holder, and torque thesheave bolt to specification.

Primary sheave holder:TLS-90018-80-00 (U.S.A.)90890-01701

Tightening torque:

Tighten the bolt to A to properly seatthe primary sheave on the crankshaft.Loosen the bolt, then torque it to B, thefinal torque.

A: 10 m-kq (72 ft-lb)B: 5.8 m-kg (42 ft-lb)

~5. SECONDARY SHEAVE

Ramp Shoe

.—

~jrCliP<:d. Colla, Bearlnq Cage ‘

. ~~~~ ‘» Spdng Seat

B»»,ong ~~Irl/3!!J;(J;;;1 fir.,’7 ~~

~~

Fixed Sheave

A. Removal1. Lock the brake, and install the second­

ary sheave holder. Fit the tool behindthe spring seat so it will hold the slidingsheave in place when the fixed sheave isremoved. Remove the securing nut.

Secondary sheave holder:90890-01872

1. Secondary sheave holder

2. Using the 3~way puller, remove the fixedsheave.

3-WayPuller Ass’y: TLU-90901-05-20 (U.S.A.)

1. 3-WayPuller Body: 90890-018482. 3-Way Puller Attachment: 90890-01873

3. Remove the key from the [ackshaft.4. Very carefully remove the secondary

sheave holder. The spring will force thesheave out.

5. Remove the sliding sheave, the spring,and the spring seat. The spring seat has aleft-hand thread. If it is difficult toremove the spring seat, rap it with aplastic mallet.

6. Remove the collar and the circlip fromthe jackshaft bearing cage.

8. Inspection1. Inspect both sheaves. If either is warped,

replace it.2. Inspect the ramp shoes on the sliding

sheave; replace as necessary.3. Check the sheave bushings for wear;

replace the sheave as required.4. Check the spring. If it is fatigued or

damaged, replace it.

C. Assembly1. Install the circlip and collar into the

jackshaft bearing cage.2. Thread the spring seat onto the jack­

shaft; it has a left-hand th read. Thespring seat must be tight or it will comeloose when you preload the secondarysheave spri ng.

3. Install the spring into the spring seat. Besure the spring is in one of the holes.

NOTE: _

The three holes in the spring seat are for con­venience only. Seating the spring in a differ­ent hole will not change the spring preload.

4. Install the sliding sheave onto the jack­shaft. Be sure the spring engages the holein the sheave.

5. Starti ng from the free position, rotatethe sliding sheave clockwise to preloadthe spring, and push the sheave towardsthe chain case. Lock the sliding sheave inplace with the secondary sheave holder.

Secondary sheave holder:90890-01872

Preload:Turning the sliding sheave 1/3 of aturn from the free position (past oneramp shoe) sets the spring at 1600

•

Turning the sliding sheave 2/3 of atu rn from the free position (past tworamp shoes) sets the spring at 2800

•

Std. secondary spring preload:1600 (Twist augle)

6. Install the key in the jackshaft, andinstall the fixed sheave. Grease theindicated point.

4-6. CHAIN CASE

7. Install the washer and securing nut.Torque the nut to specification.

Tightening torque:4.0 rn-kq (29 ft-lb)

8. Wipe both sheaves. They should be freefrom oil and grease.

4-10

A. Disassembly

1. Remove the secondary sheave from thejackshaft (Refer to 4-5, A «Removal.»)

2. Remove the bearing cage from behindthe jackshaft bearing.

3. Disconnect the brake cable from thehandlebar. It will be helpful to loosenthe cable at the caliper. The caliper neednot be disassembled.

4. Place an oil pan beneath the drain holeunder the chain case.

5. Remove the chain case cover, and let theoil drain into the oil pan.

6. Loosen the chain tension.7. Remove the securing hardware and

washers from both the drive and drivensprockets.

8. Remove the drive chain and bothsprockets.

9. Remove the collar from behind eachsprocket.

10. Remove the three secu ring bolts andremove the chain case.

4-11

11. Remove the jackshaft from the left sideof the snowmobile.

B. Inspection1. Inspect the brake disc. Place it on a sur­

face plate and check around the edgeswith a feeler gauge. If the gap is uneven,the disc is bent and must be replaced.

2. Inspect the bearing surfaces of the jack­shaft. If worn or bent, replace the jack­shaft.

3. Inspect the bearings in the chain case.If the movement is rough or uneven,replace the bearings.

4. Inspect the drive and driven sprockets;replace if worn.

5. Inspect the drive chain; replace as neces­sary.

6. Inspect the adjusting block. If the raisedboss is worn to the base of the block,replace the block.

1 Wear limit 6 mm (0.24 in)

C. GearingUse the chart below to change the chain casegearing to suit the local conditions and therider’s driving style.

Higher gearing will increase the ma­chine’s top speed.Lower gearing will increase the ma­chine’s acceleration and climbing ability.

Do not set the gearing to any of the indicated(X) settings.

~ 11T 12T 13T 14TDriven gear

21T X X X 044

S.T.D.22T X X 0 X

44

23T X 0 X X44

24T 0 X X X*44

* No. of chain links

D. Assembly1. Grease the inner surfaces of the bearings

and oil seals in the chain case.2. Place the brake disc between the brake

pads. Be sure the raised side of the discfaces away from the chain case.

3. Loosely bolt the chain case in place inthe chassis. It may be helpful to blockup the chassis to relieve the tension onthe drive axle.

4-12

4. Grease the bearing surfaces of the jack­shaft. Place the key in the jackshaft, andinstall the jackshaft from the left-side ofthe machine. The splined end must gothrough the brake disc and into thechain case. Align the keyway in thedisc with the key on the jackshaft.

5. Tighten the chain case bolts and torquethem to specification.

Tightening torque:2.3 m-kg (17 ft-Ib)

6. Install the jackshaft bearing on the leftside of the machine. Install the bearingcage over the jackshaft bearing. Torquethe three bolts to specification.

Tightening torque:2.3 m-kg (17 ft-lb)

7. Install the collar and the circlip into thebearing cage.

8. Install both collars in the chain case. Thelarger goes on the jackshaft, the smalleron the drive axle.

9. Place both the drive and driven sprocketsin the drive chain, and install them in thechain case. Be sure the stepped side ofthe driven sprocket faces in towards theengine.

10. Install the adjusting block.

11. Secure the drive and driven sprocketsonto their respective shafts. Torque thesecuring hardward to specification. Usea new cotter pin with the drive sprocket.

Tightening torque:Drive sprocket nut: 4.0 rn-kq

(29 ft-lblDriven sprocket bolt: 2.3 rn-kq

(17 ft-lb)

12. Adjust the chain tension. Turn theadjusting bolt until the chain deflectionequals specification. Torque the lock nutto specification.

Chain deflection8 ‘» 15 mm (0.3 ‘» 0.6 in)

Tightening torque:3.5 m-kq (25 ft-lb)

1. Chain deflection

13. Install the chain case cover. Torque thetwo bolts to specification. Be sure therubber gasket is properly seated on thechain case.

Tightening torque:1.6 m-kq (12 ft-lb)

14. Add oil to the chain case until oil beginsto flow from the oil drain bolt.

Recommended oil:SAE 75W80 API-GL3 Gear Oil

4·13

1. Oil drain bolt

15. Install the secondary sheave onto thejackshaft. (Refer to 4-5, C «Assembly.»)

16. Reconnect and adjust the brake cable.(Refer to 4-7, D «Brake Adjustment.»)

4-7. BRAKE

A. Disassembly1. Remove the brake cable from the

handlebar. Loosen the adjuster at thecal iper, then remove the cable.

2. With a pair of pliers, left the arm of eachof the return springs off the chain caseto release the preload.

4·14

3. Remove the clevis pin and disassemblethe brake.

B. Inspection

1. Check the brake pads. If either is wornbeyond the wear limit, replace the padsas a set.

Wear limit: 1.0 mm (0.04 in)

1. Wear limit

2. Replace any fatigued return spring.

C. Assembly1. When assembling the brake caliper, be

sure that hooked end of each returnspring is seated in the brake arm beforeinstalling the clevis pin. Assemble thebrake as shown in the exploded illustra­tion. Always use a new cotter pin.

2. Preload the lower spring first, then theupper spring. Using a pair of pliers, liftthe spring up and over the chain case.

3. Connect the brake cable to the handle­bar.

4-15

D. Brake Adjustment

The brake is adjusted at two points so thatthe gaps between the disc and pads are equaland within tolerance. Proper adjustment willresult in 6 ‘» 7 mm (0.24′» 0.28 in) free playbetween the brake lever and the brake leverholder.

1. Loosen the lock nut on the screw (innerpad adjusting screw) until the innerbrake pad is 0.2 ‘» 1.0 mm (0.008 ‘»0.04 in) from the brake disc.

2. Loosen the lock nut on the cable adjustscrew (outer pad adjusting screw) andadjust until the outer pad is 0.2 ‘» 1.0mm (0.008 ,…, 0.04 in) from the brakedisc.

3. Make sure both lock nuts are tight aftercompleting this procedure.

1. Inner pad adjusting screw 2. Outer pad adjusting screw3. Outer pad arm 4. Inner pad arm

4-8. SLIDE RAIL SUSPENSION

A. Removal1. Loosen the track.2. Seal the carburetor so fuel will not spill

when you turn the machine on its side.(Refer to 1-6, C «Sealing the Carbure­tor.»)

4-16

3. Turn the machine on its side, and lift therear torsion spring off its seat to releasethe preload. Repeat this procedure onthe opposite side.

1. Spring seat

4. Remove the two suspension bolts fromone side of the machine, turn themachine over, remove the remaining twobolts, and remove the suspension fromthe track.

B. Inspection1. Inspect the hyfax. Replace them if they

are worn beyond the wear limit. Torquethe screws to specification.

Wear limit: 8.5 mm (0.3 in)Slide runner securing screw tighteningtorque: 0.25 m-kg (2 ft-lb)

1. Wear limit: 8.5 mm (0.3 in)2. New: 13.5 mm (0.5 in)

2. Inspect the suspension wheels; replace asnecessary. Apply a thread-locking com­pound to the securing bolts, and torquethe bolts to specification.

Tightening torque:

7.0 m-kg (51 ft-lb)

4-17

3. Inspect the guide wheels; replace asnecessary. Apply a thread-locking com­pound and torque the bolt to specifica­tion.

Tightening torque:2.3 m-kg (17 ft-lb]

4. Replace any fatigued springs.5. Inspect both the front and rear stopper

bands. Replace if either is frayed ordamaged.

When installing the stopper bands, always usethe standard setting. Another setting willdamage the rear shock. Torque the nut tospecification.

Tightening torque:0.4 m-kg (3 ft-lb)

Standard setting:Front band: Lower hole (#1 hole)Rear band: Upper hole (#2 hole)

C. Installation

1. Grease the suspension where indicated inthe illustration.

2. Thoroughly grease the axle in the frontpivot arm. Tape the end caps in place.This will hold the axle within the pivotarm during installation of the suspen­sion.

3. Place the suspension in the track, andswing it into place in the chassis. Installboth front suspension-mounting bolts.Do not tighten them at this point.

4-18

4. Grease the rear axle, and install it in therear pivot arm.

5. Install both rear suspension-mountingbolts.

6. Tighten all four suspension-mountingbolts, and torque them to specification.

Tightening torque:4.5 rn-kq {33 ft-lb)

7. Place the torsion springs on their seats.8. Adjust the track tension. {Refer to 4-9,

D «Track Adjustment.»}

4-9. DRIVE

7. Remove the track.

5. Remove the suspension. (Refer to 4-8, A/I RemovaL»)

6. Place the machine on its right side.Remove the axle by lifting it up and outof the chain case, then out of the track.

A. RemovalI

1. Place an oil pan beneath the chain case,and remove the chain case cover. Let theoil drain into the oil pan.

2. Remove the driven sprocket.3. Remove the secondary sheave. (Refer to

4-5, A II Removal.»)4. Remove the axle nut and washer; remove

the bearing cage.

Bearing Cage

Drive Axle Bearing

4-19

B. Inspection1. Check the track and clips for cracks,

damage, or wear. Replace the track orclips as required.

2. Inspect the sprockets. If the lugs areexcessively worn, replace the sprockets.

3. Inspect the axle. If it is bent, excessivelyscratched, or if the splines or threads aredamaged, replace the axle.

4. When pressing the sprockets onto theaxle, be sure the lugs on each sprocketare opposite one another as shown in thephotograph. Locate each sprocket on theaxle whsre shown in the illustration.

2. Install the axle. Push the threaded endup towards the secondary sheave, theninstall the splined end into the chaincase. Be sure the lugs correctly engagethe track.

3. Install the bearing and the bearing cageonto the drive axle. Torque the threebolts to specification.

Tightening torque:2.3 m-kg (17 ft-lb)

4. Install the washer and the axle nut.Torque the nut to specification.

Tightening torque:8.0 m-kg (58 ft-Ib)

Track deflection: 25,.., 30 mm/10 kg1.0″» 1.2 in/22 Ib)

5. Install the slide rail suspension. (Refer to4-8, C II Installation.»)

6. Reassemble the chain case, and add oil.(Refer to 4-6, D «Assernolv.»)

D. Track AdjustmentThe track tension should be adjusted so thattrack deflection will equal specification whenthe track is pulled at the middle by a force of10 kg (22 lb].

178.4 mm{7.1 in}

211.4 mm(8,5 in)

63mm(2.5 in)

138.6 mm(5.5 in)

105.6 mm(4.2 in)

~wD\1

~—. .—~

~~~Turning direction

C. Assembly1. Place the track in the chassis. Be sure it

is positioned as shown in the illustration.

4-20

1. Turn the track by running the engine.2. Loosen the lock nuts, and turn both the

right and left track adjusting bolts untilthe track is aligned with the slide rail asillustrated.

No good

Slide runner

1. Lock nut

Good

Slide runner

2. Adjusting bolt

No good

Slide runner

Track metal

~Forward

Gap between slide runnerand edge of track window.

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

3. Check the track deflection. It shouldequal the specified value.

4. If it does not, repeat the above proce­dures until deflection equals specifica­tion.

5. Tighten the track adjusting lock nuts.Torque to specification.

Track metal

~ -lL:Forward

Gap between slide runnerand edge of track window.

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

Tightening torque:3.5 rn-kq (25 ft-lb)

CHAPTER 5. CHASSIS

5-1. STEERING 5-1A. Assembly 5-1B. Adjustment 5-2

5-2. SKiS 5-3A. Inspection 5-3B. Assembly 5-4

5-3. OIL TANK 5-4

5-4. FUEL TANK 5-5

CHASSIS

5-1. STEERING

Steering Column_—-i

A. Assembly1. Secure the steering relay rods (with the

universal joint attached) to the outsidearm. Torque the flange nut to specifica­tion and install a new cotter pin.

Tightening torque:3.0 m-kg (22 ft-lb)

5-1

2. Install the steering column onto theframe. Grease the upper and lower bear­ings. Torque the bolts to specificationand bend the lock tab.

Tightening torque:

2.5 m-kg (18 ft-lb)

Tightening torque:2.0 m-kg (15 ft-lb)

3. Connect the steering relay rods to thesteering column. Torque the flange nutto specification and install a new cotterpin.

Tightening torque:

2.5 m-kg (18 ft-lbl

Front

1. Ski spindle center

A C =0″‘» 6 mm (0 «»‘ 0.23 in) B. Ski width

B. Adjustment1. Straighten the handlebars and check to

see that the skis are parallel. If not,loosen the steering relay-rod lock nut.By turning the steering relay rod, adjustthe ski toe-out to specification. Torquethe lock nut to specification.

Ski stance: 750 mm (29.53 in)Ski toe-out: 0 — 6 mm (0 — 0.23 in)

5-2

2. The height of the handlebars can beadjusted to suit the rider’s preference.After adjusting the handlebars, alternate­ly tighten the four securing bolts. Main­tain the specified gap in the steeringclamps. Torque the bolts to specifica­tion.

Tightening torque:1.4 m-kg (10 tt-tb)

1. Clamp2. HandJebar

5-2. SKIS

A. Inspection1. Check the ski runner. Replace it if it is

excessively worn. Torque the nuts tospecification.

Tightening torque:1.4 m-kg (10 ft-lb]

2. Inspect the leaf spring and the spring re­taining pins. If the spring is fatigued or ifa pin is worn, replace them as necessary.Torque the securing nut to specificationand install a new cotter pin.

5-3

Tightening torque:Spring nut: 1.4 m-kg (10 ft-Ib)

3. Check the wear plate. Replace it if it isworn.

B. Assembly1. After assembling the ski, thoroughly

grease the wear plate and all retainingpins.

2. Carefully install the ski onto the skicolumn. Tighten the securing bolt untilit is tight, then back it out 1/4 turn.Tighten the slotted nut, and install a newcotter pin.

3. When installing the ski shock, secure thebottom end to the sk i then secu re the

5-3. OIL TANK

top end to the ski column. All collarsshould be greased, and securing nutsshould be torqued.

Be sure to install the shock with the worduyAMAHA» facing upward.

Tightening torque:1.45 m-kg (10.5 ft-lb)

Oil Gauge Line

OilLine~ …….-l.

~~

rf~

IiJ

(p/

5-4

1. Check the oil line from the tank to thepump. It should be free from all obstruc­tions and shouId not be pinched or

damaged in any way. Replace as neces­sary.

‘~~ Fuel Gauge Line

<,I

1. Check all lines. If any are cracked,crimped, or damaged in any way, replacethem.

2. Be sure all lines are secured in place by aretaining clip.

3. Be su re that all Iines are routed as shownin the Cable Routing Diagram in theappendix. The breather pipe must berouted so that no fuel will leak duringoperation.

4. Replace the fuel filter each season.5. When reinstalling the fuel tank, torque

the four securing bolts to specification.

Tightening torque:1.0 m-kq ( 7 ft-Ib )

CHAPTER 6. ELECTRICAL

6-1. IGNITION SySTEM 6-1A. Circuit Diagram 6-1B. Troubleshooting 6-1C. Ignition Timing 6-2D. Spark Gap Test 6-3E. Ignition Coil 6-4F. Spark Plug 6-4G. Pulser and Charge Coil. 6-5H. C.D.1. Unit 6-5

6-2. LIGHTING SYSTEM 6-6A. Circuit Diagram 6-6B. Headlight Beam 6-6C. Lighting Coil 6-7D. Voltage Regulator 6-7

ELECTRICAL

6-1. IGNITION SYSTEM

A. Circuit Diagram

B. Troubleshooting

No spark is produced or weak.

Check of connections_____~—.JI Check lead wire connections for short circuits.

—1———-,OK Faulty. Correct.

SparkS See 6-1, D «Spark Gap Test.»

F= •No spark Spark. Plug is faulty .

OK..

……………………. Measure coil resistance.(See 6-1, G «Pulser and Charge Coil.»)

FauIty———…Replace .

6-1

Faulty——.. Replace.OK

……………………. Measure coil resistance.’——.—_……

(See 6-1, G «Pulser and Charge Coil.»)

………………….. Ignition coil test (See 6-1, E «Iqnition Coil.»)

OK Replace.

C.D.I.?g See 6-1, H. «C.D.1. Unit.»

+Faulty • Replace.

The engine starts but will not pick up speed.

…………………………… Clean or replace (See 6-1, F «Spark Plug.»)

……………………. Make continuity test’—__—,— …J (See 6-1, G «Pulser and Charge Coil.»)

OK

……………. (See 6-1 , C «lqnition Timing.»)

………………………….. (See 6-1, H «C.D.1. Unit.»)

L————….Faulty——.~Replace.

Dial gauge stand: 190890-01195

3. Insert the dial gauge with the needle intothe stand.

C. Ignition Timing1. Remove the starter from the engine.2. Remove the spark plug, and screw the

dial gauge stand into the spark plug hole.

4. Rotate the flywheel magneto until thepiston is at top-dead-center (T.D.C,).Set the dial gauge at zero. Tighten theset screw on the dial gauge stand tosecure the dial gauge assembly. Rotatethe flywheel back and forth to be surethat the indicator needle does not gopast zero.

5. Starting from T.D.C., rotate the flywheelcounterclockwise until the dial gaugereads 3-1/2 needle revolutions beforetop-dead-center.

90890-03097

90890-03098Dial gauge needle:

Dial gauge:

6-2

6. Slowly turn the flywheel clockwise untilthe dial gauge indicates the specifiedignition timing.

Ignition timing (B.T.D.C.);1.6 mm (0.062 in)

7. The marks on the coil plate should alignwith the timing mark on the magneto. Ifnot, adjust the timing.

8. Loosen both coil plate screws.

9. Rotate the coil plate by using a screw­driver at the pry points. Align the markson the coil plate with the mark on theflywheel. Tighten the screws and torquethem to spec.

Tightening torque:0.65 m-kg (5 ft-Ib)

6-3

10. Remove the dial gauge stands. Reinstallthe starter and the spark plug. Torquethe plug to specification.

Tightening torque:2.8 m-kg (20 ft-lb)

D. Spark Gap TestThe entire ignition system can be checked formisfire and weak spark by using the ElectroTester. If the ignition system will fire acrossa specified gap, the entire ignition system isgood. If it will not fire across the gap, pro­ceed with the individual component testsuntil the problem is located.

Electro tester: 90890-03021

1. Thoroughly warm up the engine so thatall electrical components are at operatingtemperatu reo

2. Stop the engine, and connect the testeras shown.

®

1. Electro-Tester 2. Plug wire from coil 3. Spark plug

3. Start the engine, and increase the sparkgap until misfire occurs.

Minimum spark gap: 9 mm (0.35 in)

E. Ignition Coil1. Coil spark gap testa. Remove the ignition coil from the frame.b. Connect the Electro Tester as shown.c. Connect a fully charged battery to the

tester.d. Turn on the spark gap switch, and in­

crease the gap until misfire occurs.

nx 1

63001——+…

Minimum spark gap: 9 mm (0.35 in)

1. Battery 2. 6 mm (0.24 in)

Spark plug color

No.1 Good (Carburetor is tuned properly.)

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

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

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

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

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

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

Bad (Due to lean a mixture, the sparkplug rnelts.)Check the piston for holes or seizure.

No.6Check the cooling system, gasoline octanerating and ignition timing. After replacingthe spark plug with colder type, tune thecarburetor again starting with low-speed

,tuning.

—-fIIo’- Primary coil resistance—….. Secondary coil resistance

F. Spark Plu9The Iife of a spark plug and its condition varyaccording to the habits of the rider. You canlearn a great deal about the operating condi­tion of an engine by studying the spark plug.Examine the spark plug at each periodicinspection, and replace it with a suitable plug.Ask the customer how long and how fasthe rides his snowmobile, and recommend ahot, standard, or cold plug accordingly.Encourage your customers to change thespark plug regularily. Their snowmobiles willrun better, and fuel consumption will remainlow.

Secondary coilresistance

5.9 kn ± 20%at 20°C (68°F)

Primary coilresistance

1.0n ± 10%at 20°C (68

0F)

2. Coil winding resistance testsUse a pocket tester to determine resist­ance and continuity of the primary andsecondary coil windings.

MITSUBISHF6T411

Manufacturer

6-4

InspectionInstruct the rider to:

1. Inspect the clean the spark plug every400 km (250 mi) or 20 hours.

2. Clean the electrodes of carbon andadjust the electrode gap.

3. Be sure to use the proper reach plug toavoid overheating, fouling, or pistondamage.

Spark plug type: NGK BR8HS

Spark plug gap (use wire gap gauge):0.6 — 0.7 mm (0.023 — 0.028 in)

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

G. Pulser and Charge CoilCheck the resistance of each coil as shown inthe illustartion. If the resistance is not withinspecification, the coil is not working. Checkthe connections. If the connections are good,the coil is damaged internally; it should bereplaced.

Pocket tester: 90890-03112

Charging coil resistance:Black to Brown leads:

426Q ± 10% at 20°C (68° F)

Pulser coil resistance:Black to White/Red leads:

20Q ± 10% at 20°C (68° F)

1. Yellow2. Brown3. Black4. White/Red5. Flywheel magneto6. Pocket tester7. Set tester at «RX1» position

®426Q (Charge Coil)

(Pulser Coil)

20Q

i- L…:.._—,..,…III

CDC] IL..—::::=~~\- @ :

I~—+®-t:>_—j I®c::J———- J

Pulser Coil —­Charge Coil—

H. C.D.1. UnitIf the ignition system malfunctions and all ofthe above components are working properly,then the C.D.1. unit is faulty; replace it.

6-5

6-2. LIGHTING SYSTEM

A. Circuit Diagram

B. Headlight Beam1. Inspection

Check the headlight beam direction. Thehigh beam must be directed downwardat an angle of 1/2 0 to the horizontal line.

2. AdjustmentWhen necessary, adjust the headlightbeam by tightening or loosing the fourheadlight mounting screws.

~—— Q——__-4

Horizontal line

h

Q 3.0 m (0 ft) 7.6 m (25 ft)

h 26 mm (1.0 in) 66 mm (2.6 in)

6-6

o

\

C. Lighting CoilCheck the resistance between the yellow leadand ground. If the resistance is not withinspecification, the coil is not working. Checkthe connections. If the connections are good,the coil is broken internally; it should bereplaced.

O.23Q±20%

D. Voltage Regulator

Lighting coil resistance:Black & Yellow:

0.23Q ± 20% at 20°C (68°F)

r-===»,.,—-®

Qx 1

1. Yellow2. Brown3. Black4. White/Red5. Flywheel magneto6. Pocket tester7. Set tester at «RX1» position

Voltage regulator

Instruments required for inspection:• Voltage Regulator Tester:

90890-03090

• Two 12V batteries• One jumper

Connect the tester, batteries, and the voltageregulator as shown in the illustration.

6-7

24V

000 Battery00

+ 0

Tester

Inspection1. Check the battery voltage.

Set the left and right switches to»VOLT» and Jl12V». If the checkerneedle reads 20 volts or more, batteryvoltage is sufficient.

611 []::J1211

REG

@ REGULATOR©CHECKER (f)

Light

YAMAHA 06\/ []::J12\/ ~

REG IIOLT ~ElI] ~e REGULATOR CHECKER (f)

Replace the regulator

2. Check the tester.Set the right switch to JlREG.» If thelamp lights up, there is continuity in thetester. Proceed with the tester.

3. Test the regulatorSlowly turn the tester knob clockwise;the needle will move with the knob. Ifthe needle quickly returns to zero themoment it enters the black area on thescale, then the working voltage of thethyristor is good; the voltage regulatoris working properly.If the needle swings into the black areaof the scale but will not return to zero,the regulator is faulty and should bereplaced.

Thyristor working voltage:13.8 ± 0.5 volts at 5,000 r/min

light is out

YAMAHA 0611OB

1211 ~

REG f[) \/OLT @e REGULATOR CHECKER (£l

Regulator is good

6-8

CHAPTER 7. APPENDIX

7-1. SPECIFICATIONS 7-1

7-2. TIGHTENING TORQUE 7-4

7-3. CONVERSION TABLES 7-6

7-4. EXPLODED DIAGRAMS 7-7Recoil Starter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7-7Flywheel Magneto. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7-8Oil Pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7-9Oil Pump Drive Gear 7-10Top End 7-11Bottom End 7-12Carburetor 7-13Intake 7-14Primary Sheave 7-15Secondary Sheave 7-16Chain Case 7-17Brake 7-18Slide Rail. 7-19Suspension Wheels 7-20Drive Axle 7-21Steering 7-22Ski. 7-23Ski Shock 7-24Oil Tank ‘ 7-25Fuel Tank » 7-26Electrical Components (1) 7-27Electrical Components (2) 7-28Control Cables 7-29

7-5. WIRING DIAGRAM 7-30

7-6. WI RE AND CABLE ROUTING 7-32

7-1. SPECIFICATIONS

A. General

APPENDIX

Model BR250F

Model:Model (I.B.M. No.) BR250F (8R4)Frame 1.0. & starting number 8R4-000101Engine 1.0. & staritng number R246-000101

Dimension:Overall length 2,360 mm (92.9 in)Overall width (std) 870 mm (34.3 in)Overall height (w/windshield) 940 mm (37.0 in)

Weight:Net weight 130 kg (286.6 Ib)

B. Engine

Description:Engine typeEngine modelDisplacementBore x StrokeEffective compression ratioStarting systemIgnition systemLubrication system

Cylinder:MaterialBore sizeTaper limitOut of round limitCombustion chamber volumeCompression chamber type

Piston:Piston skirt clearance (Measuring point)

Piston oversize

Piston pin outside diameter x length

Piston ring:Piston ring design (Top)Piston ring design (2nd)Ring end gap (installed) (Top)Ring end gap (installed) (2nd)

Small end bearing:Type

Big end bearing:Type

Fan cooled two-stroke 5-portR246246 ern» (15.01 cu. in)70 x 64 mm (2.76 x 2.52 in)6.1 : 1Recoil hand starterC.D.!.IIAutolube» oil injection

Cast iron sleeves aluminum70 mm (2.76 in)0.05 mm (0.0020 in)0.01 mm (0.0004 in)24.8 crrr’ (1.51 cu. in) with spark plugDome + Squish

0.045,…., 0.050 mm (0.0018′» 0.0020 in)(10 mm from piston skirt end)1st 70.25 mm (2.766 in)2nd 70.50 mm (2.776 in)¢18 x 55 mm (¢0.709 x 2.165 in)

KeystonePlain0.20′» 0.40 mm (0.0078′» 0.016 in)0.20′» 0.40 mm (0.0078′» 0.016 in)

Needle bearing

Needle bearing

Crankshaft:Crankshaft assembly width (A)

Crankshaft deflection (0)Connecting rod big end side clearance (C)Connecting rod small end deflection (P)

+ 0 ( 20 + 0.039 in]56 _ 0.05 mm 2. 0.00197 In

0.02 mm (0.0008 in)0.25 — 0.75 mm (0.010 — 0.030 in)2.0 mm (0.079 in)

A

D rc1 D

CLUTCH SIDE c:t{rI~100 mm (3.9 in)l—~11-ooc—l80 mm (3.1 in)

Crank pin outside diameter x lengthCrank pin typeCrank bearing type (Left) x q’tyCrank bearing type (Right) x q’tv

Crank oil seal type (Left) x q’tyCrank oil seal type (Right) x q’tv

Carburetor:Type & manufacturer/quantity1.0. MarkMain jet (M.J.)Pilot screw (P.S.)Throttle valve (Th.V.)Valve seat (V.S.)Float heightIdling engine speed

Lubrication:Autolube pump — Color codeAutolube pump — Minimum strokeAutolube pump — Maximum strokeAutolube pump — Reduction ratioAutolube pump — Output Min./200 strokesAutolube pump Output Max./200 strokesAutolube pump wire free playOil tank capacityOil grade

C. Drive and track suspencion

Transmission:TypeDrive ratioEngagement rpmShift rpmPrimary spring:

Part No.Color code

1>24 x 55 mm (1)0.945 x 2.165 in)Solid shaft#6306 special x 1 pc.#6305 special x 1 pc,S03-30 x 1 pc,505-25 x 1 pc,

B032-28 KEIHIN x 1 pc,8R401#1081-1/4 turns outt;;;; 1.01>1.4 mm (1)0.055 in)15 ± 2 mm (0.59 ± 0.08 in)1100 ± 100 r/rnin

Pink0.20 — 0.25 mm (0.0079 — 0.0098 in)1.65 — 1.87 mm (0.0650 — 0.0736 in)1/400.95 — 1.19 crrr’ (0.0321 — 0.0402 oz)7.84′» 8.89 ern» (0.2508 — 0.3006oz)

25 ± 1 mm (0.98 ± 0.04 in) at idle1.75YAMALUBE 2-cycle

V-belt automatic centrifugal engagement3.5: 1 ,…, 1 : 13100 ± 200 r/min5,700 — 5,800 r/min

90501-50654No painted

7-2

Secondary spring:Part No.Color code

Secondary spring pre-load (twist)Sheave distanceSheave off-setV·belt width and outer line lengthV-belt wear limit

Track suspenisonTypeDamper typeSpring color code (Front)Spring color code (Rear)Slide runner wear limitStopper band length/Hole No. (Front)Stopper band length/Hole No. (Rear)Track widthTrack deflectionLength on groundWheel sprocket material and number of teeth

Chain:TypeReduction ratioChain pitch x Number of links

Free play

Chain housing oil quantityChain housing oil grade

Brake:TypeBrake pad thicknessBrake pad wear limitGap between pad and disc

D. Chassis

Frame:Material

Steering system:Caster (ski column)CamberSki length x width x thicknessSki stanceSki toe-outSteering linkage typeLock to lock angle (ski)

Lock to lock angle (steering column)

Front suspension:TypeDamper type

Fuel tank:CapacityFuel grade

90508-40506No painted160°266 ± 2 mm (10.47 ± 0.08 In)

! 11 ± 3 mm (0.43 ± 0.12 in)31.6 x 1,099 mm (1.24 x 43.3 in)26 mm (1.02 in)

Slide rail suspensionOil and gas damperGreen — GreenNo painted8.5 mm (0.335 in)218.5 mm (8.60 in) No.1152 mm (5.98 in) No.2381 mm (15 in)25″»‘ 30 mm/10 kg (0.984 — 1.18 in/22 lb]600 mm (23.6 In)Polyethylene 9T

Chain (#40K-l)22/13 (1.692)12.7 mm (0.5 in) x 44L

10 + 5 mm (04+ 0.2 «In)2 . — 0.08

200 crrr’ (6.8 oz)Gear oil API «G L3» (SAE #75 or 85)

Disc brake7.3 mm (0.287 in)1.0 mm (0.04 in)0.2 — 1.0 mm (0.008 — 0.039 in)

Steel

25°0°980 x 120 x 1.6 mm (38.6 x 4.7 x 0.06 in)750 mm (29.5 in)0-6 mm (0—0.23 in)Tie-rodRight ski, L: 26.8° R: 30.5°Left ski, L: 30.5° R: 26.8°Right: 55°Left: 55°

Leaf springOil damper

15 liter (4 US.gal)Regular gasoline

7-3

E. Electrical

Ignition system:Type flywheel magneto (C.D.I. type)

Model/manufactu rer F8R4/YAMAHAVoltage 12VPluser coil resistance 20n ± 10% at 20°C (68°F) (White/Red — Black)Charging coil resistance 426n ± 10% at 20°C (68°F) (Brown — Black)

Ignition timing:B.T.D.C. 1.6 ± 0.1 mm (0.063 ± 0.004 in)

Ignition coil:Model: Manufacturer F6T411/MITSUBISHISpark gap 9 mm (0.4 in)/300 r/min

11 mm (0.6 in)/3,000 r/minPrimary winding resistance 1.0n ± 10% at 20°C (68°F)Secondary winding resistance 5.9kn ± 20% at 20°C (68°F)Diode (Yes or No) No

Spark plug:Type & quantity NGK BR8HS x 1 pes,Spark plug gap 0.6″‘-‘ 0.7 mm (0.024″‘-‘ 0.028 in)

Spark plug cap:Type Resign typeResistance 5kn ± 25% at 20°C (68°F)

C.D.I. unit:Model/Manufacturer 8R4/YAMAHA

Lighting system:Lighting output 12V-l00WLighting coil resistance 0.23n ± 20% at 20°C (68°F) (Yellow — Black)Headlight type Semi shieldBulb wattage/q’ty 12V-60/60W x 1 pc.Tail/stop light wattage 12V-8W/23W

A.C. regulator:Model/manufacturer TRIZ-50 HITACHI/S85168 TOSHIBAVoltage 13.8 ± 0.5V

7-2 Tightening torque

,

Part to be tightened Thread size Tightening torque Remarks

[Engine]Spark plug M14 P1.25 2.8 m-kg (20 ft-lb]Cylinder M8 P1.25 First: 2.0 m-kg (14.5 ft-lb)

Final: 2.5 m-kg (18 ft-lb]Flywheel magneto M16 P1.9 7.3 m-kg (53 ft-lb)Crankcase upper and lower M8 Pl.25 First: 1.0 rn-kq (7 ft-lb) I

with engine bracketI

Final: 2.5 m-kg (18 ft-lb)Tightening sequence

1

71 0 35 0

0 0

— 1—,

0 08 0

~42

Fan I M6 PLO I 0.7 m-kg (5.1 ft-lb) Use Loetite®

7-4

Part to be tightened Thread size Tightening torque Remarks

Oil pump gear case M6 P1.0 0.7 m-kg (5.1 ft-Ib)

[Drive and track suspension]Primary sliding sheave and cap M6 P1.0 1.1 m-kg (8 ft-lb)

Installation of primary sheave UNF 1/2″ Initial: 10 m-kg (72.5 ft-lb) Use motor oilLoosen once and retighten:6.0 m-kg (43.5 ft-Ib)

Installation of secondary sheave M12 P1.25 4.0 m-kq (29 ft-lb]Installation of drive chain sprocket M12 P1.25 6.0 m-kg (43.5 ft-Ib) Use cotter pinInstallation of driven chain sprocket M8 P1.25 2.3 m-kg (16.5 ft-lb]Chain housing and frame M8 P1.25 2.3 m-kg (16.5 ft-Ib)Chain hosing cap M6 P1.0 0.65 m-kg (5 ft-lb)Chain tensioner lock nut M10 P1.25 3.3 m-kg (24 ft-lb)Installation of front axle L.H. M20 P1.0 8.0 m-kg (58 ft-lb)Front axle housing and frame M8 P1.25 2.3 m-kg (16.5 ft-Ib)Shaft 1 and frame M10 P1.25 5.5 m-kg (40 ft-lb]Pivot arm 1 and sliding frame 1 M10 P1.25 5.0 m-kg (36 tt-lb) Use Loctite®Suspension wheel M12 P1.25 7.3 m-kg (53 ft-lblSpring hook M8 P1.0 2.3 m-kg (16.5 ft-lb}Sliding frame 1 M8 P1.25 2.3 m-kg (16.5 ft-Ib)Rear guide wheel M8 P1.25 2.3 m-kg (16.5 ft-lb)SIiding runner 1 M6 P1.0 0.25 m-kg (2 ft-lb) Use Loctite®Sliding runner 2 M6 P1.0 0.65 m-kg (5 ft-lb]Stopper 1 M6 P1.0 0.4 m-kg (3 ft-lb)

[Chassis]Engine mounting bolt M10 P1.25 3.0 m-kg (22 ft-lb)Ski runner M8 P1.25 1.4 m-kg (10 ft-lb)Steering column and gate M8 P1.25 2.0 m-kg (14.5 ft-lb) Use lock

washerSteering relay rod adjusting nut M10 P1.25 2.5 m-kg (18 ft-lb] Use Loctite®Outside arm and ski colume M10 P1.25 3.0 m-kg (22 ft-lb] Use lock

washerSteering lower bracket M8 P1.25 2.0 m-kg (15 ft-Ib) Use lock

washerInstallation of steering column 1,2 M8 P1.25 1.45 rn-kq (10.5 ft-lb)Steering relay ass’y M10 P1.25 3.0 m-kg (22 ft-lblUniversal joint and outside arm M10 P1.25 2.5 m-kg (18 ft-lb)

7-5

GENERAL TORQUE SPECIFICATIONS

This chart specifies torque for standardfasteners with standard 1.8.0. pitch threads.Torque specifications for special componentsor assemblies are included in the applicablesections of this book. To avoid warpage,tighten multi-fastener assemblies in a criss­cross fashion, in progressive stages, until fulltorque is reached. Unless otherwise specified,torque specifications call for clean, drythreads. Components should be at roomtemperature.

CONVERSION TABLES

METRIC TO INCH SYSTEM

Known Multiplier Result

rn-kq 7.233 ft-Ibm-kg 86.80 in-lbem-kg 0.0723 ft-lbem-kg 0.8680 in-lb

kg 2.205 Ibg 0.03527 oz

km/lit 2.352 mpgkm/hr 0.6214 mphkm 0.6214 mim 3.281 ftm 1.094 ydcm 0.3937 inmm 0.03937 in

ee (em3) 0.03382 oz (U.S. liq)

ee (ern») 0.06102 eu.inlit (liter) 2.1134 pt (U.S. liq)lit (liter) 1.057 qt (U.S. Iiq)lit (liter) 0.2642 gal (U.S. liq)

kg/mm 56.007 Ib/inkg/em2 14.2234 psi (lb/in2

)

Centigrade (oC) 9/5 (oC)+ 32 Fahrenheit (F)

7-6

General torqueA B specifications

(Nut) (Bolt) m-kg ft-lb

10 mm 6mm 0.6 4.5I

12mm 8mm 1.5 I 11

14mm 10mm 3.0 22

17 mm 12 mm 5.5 40

19mm 14 mm 8.5 51

22mm 16mm 13.0 94

INCH TO METRIC SYSTEM

Known Multiplier Result

ft-lb 0.13826 rn-kqin-lb 0.01152 rn-kqft-lb 13.831 em-kgin-lb 1.1521 em-kg

Ib 0.4535 kgoz 28.352 g

mpg 0.4252 km/litmph 1.609 km/hrmi 1.609 kmft 0.3048 myd 0.9141 min 2.54 emin 25.4 mm

oz (U.S. liq) 29.57 ee (ern»)cu.in 16.387 ee (em»)pt (U.S. liq) 0.4732 lit (liter)qt (U.S. Iiq) 0.9461 lit (liter)gal (U.S. liq) 3.785 lit (liter)

Ib/in 0.017855 kg/mmpsi (lb/irr») 0.07031 kg/em2

Fahrenheit (F) 519 (oF) — 32 Centigrade (oC)

4 EXPLODED DIAGRAM7.

. Plate SpringDrive

d Limiter BracketHoo

L

RECOIL STARTER

7-7

FLYWHEEL MAGNETO

0.7 m-kg (5 tt-lb)

Coil Plate

———,II!IIIIIIIIII~

7.5 m-kg (54 ft-lb)

~/// /

Flywheel Magneto / / 1r———— J

II1

IIIIIIIIIIIIIIIIl~

<,<,~

«‘» <,<,,..——..»‘»

Apply Thread ‘»Locking <,

Compound «‘JI ~»———— -/—

. @ ~ C,.nk,halt

I@

~

7-8

OIL PUMP

ApplyYamabond 5To Gear CaseSide Only

ApplyYamabond 5

0.67 m-kg(4.8 ft-Ib)

AdjusitngPlate

IGrease I //

Plunger (

Oil PumpCover

Minimum Pump Stroke:0.20-0.25 mm <0.0079-0.0098 in)Maximum Pump Stroke:1.65 — 1.87 mm <0.0650 — 0.0736 in)

7-9

OIL PUMP DRIVE GEAR

7-10

TOP END

Cylinder

7-11

Cylinder Bolt

3.0 m-kg (22 ft-Ib)

Ring End Gap:Free: 6.5 mm (0.26 in)

Installed: 0.20 ‘» 0.40 mm(0.0078 ‘»‘-‘0.016 in)

Piston ClearanceMin: 0.045 mm

(0.0018 in)Max: 0.050 mm

(0.0020 in)

BOTTOM END

Bearing Support

7-12

CARBURETOR

t- Starter Jet

§a~

j'<. ~OW’f10WP’

‘1 » U ‘P’

@-FIOO’.;<.~

Main Jet

/)1(…… …

SIOWJet~

7-13

INTAKE

,Pulse Pipe (jj)….

Fuel Pump

7-14

Carburetor Boot

Spider Lever

7-15

SECONDARY SHEAVE

2.3 m-kg (17 ft-lb]

Bearing Cage

7-16

Fixed Sheave

CHAIN CASE

7-17

BRAKE

7-18

SLIDE RAIL

0.4 m-kg (3 ft-Ib)

4.5 m-kg (33 ft-lbl

Front Axle

IGrease I

Wear Limit:8.5 mm (0.3 in)0.25 m-kg (2 ft-Ib)

4.5 m-kg (35 ft-Ibl

7-19

SUSPENSION WHEELS

7-20

Guide Wheel

k · CompoundThread-Loc mg

7.0 m-kg, 51 ft-tb~

Suspension Wheel

——-.Thread-LockingCompound7.0 m-kg51 ft-Ib

178.4 mm(7.1 in)

63mm(2.5 in)

138.6 mm(5.5 in)

105.6 mm(4.2 in)

Axle Nut

I 8.0 m-kg (58 ft-lb)

Bearing Cage

DRIVE AXLE

7-21

STEERING

Outside Arm ~~

~~J rA~ Universal Join’

~

1. Clamp—~-·2. Handlebar

7-22

…·-~1.4 rn-kq (10 ft-Ib) 1

SKI

SKI SHOCK

7-24

OIL TANK

Oil Gauge Line

7·25

FUEL TANK

1.0 m-kg (7 ft-Ib)

7-26

ELECTRICAL COMPONENTS (1)

Voltage Regulator

7-27

Main Swith

ELECTRICAL COMPONENTS (2)

Engine Stop Switch

7-28

Throttle Lever

CONTROL CABLE

7-29

COl unit

ro1~ ~

CD

QQ!Xl -l

(O/P SPEEDOMETER LIGHT)

f9-l

Main switchi f B IB/W

S>-Cl..JCDm

Taillight/brake light

, ~ L (12V 8/23W1_. . GIY G/V : B B L-e:::J<:l-LmtlIi .~, ===~ , ,JttJ~~~~~ro

B-G~BVI I I i

OFFON

OFF

OFF

RUN

7-5 WIRING DIAGRAM

RUN

Headlight(12V 6O/60W)

()lTether switchliB/wi B

Brake Iight switchI I L IG/vi

…..wo

HI.LO.

Voltage regulator COl magneto

Color CodeG GreenB BlackY YellowL Blue0 Orange

Gy GrayBr BrownB/W BlacklWhiteW/R White/RedG/Y Green/Yellow

APPENDIX

1

4

Good

Bon

Bad

Mauvais

2

5

Bad

Mauvais

Bad

Mauvais

3

6

Bad

Mauvais

Bad

Mauvais

YAMAHA MOTOR CO.,LTD.IWATA,JAPAN

PRINTED IN U.S.A.

_YAMAHA

SNOIMOBIIE

SUPPLEMENTARYSERVICE MANUAL

LIT..12618·00·70 8Y1 ..28197..10

FOREWORD

This supplementary service manual for the BR250TJ has been published to supple­ment the BR250F service manual (L IT-12618-00-41). For complete information

on service procedures, it is necessary to use this Supplementary Service Manualtogether with the following manual.

I BR250F Service Manual (LIT-12618-00-41) r

NOTE: ~ _

The Research and Engineering Departments of Yamaha are continually striving tofurther perfect all models. Improvements and modifications are therefore inevita­ble.In light of this fact, all specifications within this manual are subject to changewithout notice. Information regarding changes is forwarded to all AuthorizedYamaha Dealers as soon as possible.

OVERSEAS SERVICEOVERSEAS OPERATIONS

YAMAHA MOTOR CO., LTO.

BR250TJ SUPPLEMENTAR~SERVICE MANUAL » . I

1984 by Yamaha MotorCorporation, U.S.A.

1st Edition, June 1984All rights reserved. Any reprinting orunauthorized usewithout the written

permission of Yamaha MotorCorporation, U.S.A.

is expressly prohibited.Printed in U.S.A.

PIN L1T-12618-00-70

Particularly important information is distinguished in this manual by the follow­ing notations:

NOTE:

WARNING:

A NOTE provides key information to make procedures easier orclearer.

A CAUTION indicates special procedures that must be followedto avoid damage to the machine.

A WARN ING indicates special procedures that must be followedto avoid injury to a machine operator or person inspecting orrepairing the machine.

CONTENTS

EXTERNAL VIEW 1

MAINTENANCE 2Periodic Maintenance 2Lubrication Intervals 3

THROTTLE OVERRIDE SYSTEM 4Description 4T.O. R.S. cancellation 5Block diagram 5

POWER TRAIN 6

PRIMARY SHEAVE 6Removal 7Disassembly 7Inspection 8Reassembly 10Installation 12

V-BELT 12Removal , , 12Inspection 12Reassembly 12

EXPLODED DIAGRAM , 13CARBURETOR , 13INTAKE 14PRIMARY SHEAVE , .. , 15DR IVE AXLE, , 16SKI , 17SLIDE RAIL 18SUSPENSION WHEELS , 19BUMPER , , 20ELECTRICAL COMPONENTS 21

SPECI FICATIONS , , 22

GENERAL SPECIFICATIONS 22

MAINTENANCE SPECIFICATIONS 24

CABLE ROUTING 35

WIRING DIAGRAM 40

EXTERNAL VIEW

-1-

MAINTENANCE

Periodic MaintenancePerform the various inspections and services at the indicated intervals; however use this schedule as

a guide only. Depending upon the operating conditions, certain components may require more fre­

quent servici ng.

Every

Check point 20 hrs. or 40 hrs. or 80 hrs. or WhenSeasonally

400 km 800 km 1,600 km necessary

(250 mil (500 mil (1,000 mil

ENGINE:

Tighteness of bolts and nuts 0

Bends, cracks, and wear

Abnormal noise 0

Loose connection and breaks in the fuel and pulse pipes

Loose connection and breaks in the oil pipes 0

Loose connection and breaks in the oil delivery pipe 0

Recoil starter

Carburetor

• Operation of starter jet 0

• Mixing adjuster (pilot screw) 0

• Idle speed adjustment

Operation and adjustment of oil pump

Cylinder compression 0

Cylinder/exhaust pipe decarbonize

~Spark plug condition, gap, and cleaning 0

Tightening of the cylinder**

DRIVE:

Tightness of bolts and nuts

Wear on slide runners

Primary drive system

V-belt 0

Secondary drive system 0

Sheave distance 0

Sheave offset 0

Brake pad wear 0

Brake operation and adjustment 0

Gu ide wheel rubber 0

Wear of track drive sprockets 0

Initial100 km

Drive track adjustment (60mi} &300 km(200 mil

Breaks in drive track 0

Bends in front and rear axles 0

Check lock washers 0

Drive chain adjustment 0

Drive chain oil level 0

** Retighten every 10 hours from the first use.

-2-

Every

Check point 20 hrs. or 40 hrs. or 80 hrs, or WhenSeasonally

400 km 800 km 1,600 km necessary(250 mil (500mi) (1,000 mil

CHASSIS:

Tightness of bolts and nuts 0

Bends and cracks 0Welaed riveted, joints

Ski adjustment 0

Ski runner wear 0

Breaks in fuel tank 0

Cleaning of fuel tank 0

Fuel filter 0

Loose connection and breaks in fuel pipe := 0

Breaks in oil tank 0

Oil filter 0

ELECTRICAL:

Wear, breakage of wire covering 0

Breaks in high· tension cord 0 b=Voltage regulator output

Operation of engine stop switch 0

Operation of throttle override system 0

Headlight 0

Taillight 0

Brake light 0

Lubrication Intervals

Every

Check point 20 hrs, or 40 hrs. or 80 hrs. or WhenSeasonally Oil/Grease

400 km 800 km 1,600 km necessary Brand name(250 mil (500mi) (1,000 mil

ENGINE:

Starter case

Oil pump control box 0 Aeroshell grease #1A or

Pump drive cover 0Esso Beacon 325 grease

Oil in the oil tank o I YAMALUBE 2-cycle oil

DRIVE:

Spider lever and pin,0

Spider roller and collar Molybedenum disulfideSecondary shaft and 0

snowmobile greasesliding sheave

Front axle housing 0

Shaft 1 and shaft 2 Light all-purpose grease

(Slide rail)

Replace chain case oil 0 Gear oil API «GL-3″SAE #75 ……. #80

CHASSIS:

Steering column lower0 ~ all-purpose greasebearing

Steering column upperbearing

0 Motor oil

Steering links 0

Ski column 0

Ski wear plate 0 Light all-purpose grease

Ski retaining pin 0

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

-3-

THROTTLE OVERRIDE SYS.TEM

WARNING:

OFF

OFF

STOP

Trouble

ON

Run

OFF

RUN

ON …. OFF

RUN

ON

OFF

Idle or Starting

o

Before restarting the engine, make sure thatthe cause of the malfunction has been cor­rected and that the engine can be operatedwithout a problem.

Throttle switch

Engine

Carburetor switch

®

Throttle override system

1. Carburetor switch2. Throttle stop screw3. Throttle cable4. Throttle switch5. Throttle valve

Description

If during operation the throttle cable or carbshould malfunction in anyway, remove yourhand from the throttle lever. The throttleswitch will be deactivated, the ignition circuitwill be interrupted and the engine will stop.

Idle or Starting

ON ~~/’~’

Run

Trouble

OFF

n

-4-

(T .O .R .S.Cancellation

T.O.R.S. cancellation

If the engine cannot started due to carburetor

switch or throttle switch failure, first separate

the connections; then, short the circuit on the

wire harness side. This will turn on the igni­tion circuit and the engine can be restarted.

In this case, the throttle override system willnot work. Go to your Yamaha dealer forimmediate service.

L_——J

Leads connection

To carbo

1. Lead from wire harness

Block diagram

2. Short

COl unitB/Y

-5-

Throttle switch

Carboswitch

B

POWER TRAINPRIMARY SHEAVE

The bolt head must be insertedas shown.

Bushing clearance:0.25 mm (0.01 in)

Apply to bottomfour threads orthread-lockingcompound suchas «LOCT ITE #640with PRIMER Tn.

Belt width:New: 31.6 mm (1.24 in)Wear limit: 28 mm (1.10 in)

…..~ Oiling Point

—Siiiiiil Greasing point

….. X No oiling or greasing is allowed

-6

Be sure the «X» on the sheave capaligns with «X» on the spider.

Bushing clearance:0.25 mm (0.01 in)

Use molybdenum spraysliberally on the weights.

1. Spider2. Plain washer3. Roller4. Bushing5. Primary sheavecap6. Fixed sheave7. Fi xed sheavestopper8. V-belt9. Sliding sheave

10. Slider11. Bush12. Plain washer13. Weight

2. Remove the sliders, rollers and weights.

3. Remove the sliding sheave bush asfollows.

3. Weight2. Roller1. Slider

NOTE: _

For this operation, the special tools andLOCTITE #640 with PRIMER «T» (requiredfor fixed sheave) are necessary. If these areunavailable, avoid disassembling.

3. Remove the primary sheave assemblywith the Sheave Holder (special tool)and Sheave Puller (special tool) asshown.

1. Sheave Holder (PING. YS·01880)

Removal1. Remove the drive guard, and remove the

V-belt.2. Remove the blind cap, and remove the

primary sheave rnountinq bolt with theSheave Holder (special tool) as shown.

1. SheaveHolder (P/NO. YS·01880)2. SheavePuller (P/NO. YS·01882)

Disassembly1. Loosen the six sheave cap securing bolts,

and remove the sheave cap and spring.

a. Immerse the primary sheave assembly inappoximately BO°C (176°F) water forseveral minutes.

b. Hold the lower piece of the ClutchSpider Separator (special tool) on arigid table usingasuitable mounting bolts.Then, install the Clutch SeparatorAdapter onto the Separator.

1. Lower piece of the Clutch Spider Separator(PING. YS·28890·A)

2. Clutch Separator Adapter (P/NO. Y5-34480)3. Mounting bolt

c. Fit the primary sheave assembly ontothe Adapter, and secure the supportingplates.

-7-

NOTE: _

Securely fit the projections of the Adapterinto the fixed sheave holes.

f. Remove the spider, sliding sheave andfixed sheave from the Clutch SpiderSeparator.

g. Remove the sliding sheave bush from thesliding sheave with Bushing Tool (specialtool) as shown.

1. Bushing Tool (special tool) 2. Bush

1. Supporting plate

d. Set the upper piece of the Clutch SpiderSeparator onto the spider as shown.

e. Remove the fixed sheave and fixedsheave stopper by turning the ClutchSeparator counterclockwise.

Inspection1. Inspect the tapered ends of the crank­

shaft and fixed sheave for scratches.If either is severely scratched, replace it.If scratches are minor, burnish thecomponent with emery cloth.

2. Check the primary sheave cap bush andsliding sheave bush for wear. If wornbeyond tolerance, replace the bush.

——— Primary sheave cap Sliding sheave

Bush clearance0.25 mm (0.01 in) 0.25 mm (0.01 in)

<Limit>

To loosen the fixed sheave, high torque isrequired. Therefore, make sure the primarysheave and special tools are placed securelyalso take care not to crack the fixed sheave.

8-

1. Feeler gauge 2. Primary sheave cap

1. Feeler gauge 2. Sliding sheave

3. Inspect the sliders for scratches or otherdamage. If any, replace them.

4. Inspect the rollers for wear. If any,replace them.

1. Roller

5. Inspect the weights for wear. If any,replace them.

-9

6. Check the spring. Replace it, if it isfatigued or damaged.

ReassemblyWhen reassembling the primary sheave,reverse the disassembly procedure. Note thefollowing points:

1. Before reassembling the primary sheave,the sheaves should be lubricated withthe low-temperature grease and motoroil as illustrated.

…….~ Oiling Point

~ Greasing point

…….X No oiling or greasing is allowed

2. Before tightening the fixed sheave, applythread-locking compound as LOCTITE#640 with PRIMER «T» to the threadportion (bottom four threads) of thespider.

1. LOCTITE should be applied only to thespecified area. Never apply to the otherareas.

2. Do not use the clutch until LOCTITEhas completely cured.

10-

Do not apply grease to the area marked X.For other parts, oiling is unnecessary.

1. Apply LOCTITE #640 with PRIMER «T»2. 4 threads

3. Tighten the fixed sheave with the specialtools to specification.

Before securing the fixed sheave, fit the fixedsheave stoppers onto the spider shaft.

To tighten the fixed sheave, high torque isrequired. Therefore, make sure the primarysheave, vise and special tools are placedsecurely also take care not to crack the fixedsheave.

Tightening torque:200 Nm (20.0 rn- kg, 145 ft·lb)

1. Fixed sheavestopper

4. Install the (oilers and weights into thesliding. sheave and spider.Torque the roller securing bolts tospecification.

NOTE: _

1. Be sure there is a washer on each side ofthe roller and weight.

2. The bolt head must be to the right of theroller asshow in the illustration.

Tightening torque:5 Nm (0.5 m- kg, 3.6 ft-Ib)

1. Washer 2. Weight3. Roller 4. Bolt5. Turning direction

-11-

5. Install the primary sheave cap onto thespider asshown.

NOTE: _

1. Before installing the primary sheave cap,use molybdenum sprays liberally on theweights.

2. Be sure the IIX» on the sheave cap alignswith the «X» on the spider.

6. Secure the primary sheave cap withthe securing bolts. Torque the bolts tospecification.

NOTE: _

Check the movement of the sliding sheave. Ifit is not smooth, disassemble the primarysheave. Then, reassemble it correctly.

Tightening torque:14 Nm (1.4 rn- kg, 10 ft-Ib)

InstallationWhen installing the primary sheave, reversethe removal procedure. Note the followingpoints:

1. Before installing the primary sheave,clean the oil off the tapered portionof the crankshaft using a lacquer thinner.

2. Before tightening the primary sheavemounting bolt, apply engine oil to thethread portion of the mounting bolt andits contact surface with the springwasher.

Inspection1. Visually inspect the V-belt for signs of

damage. Replace the belt, if it isdamaged.

2. Measure the width of the V-belt. If thebelt is worn beyond the wear limit,replace it.

Belt width:New: 31.6 mm (1.24 in)Wear limit: 28.0 mm (1.10 in)

\\\\\\II\\\

Belt length:

1,099 mm (43.26 in)

3. Measure the length of the V-belt. Itshould be within specification; if not,replace the belt.

3. Tighten the mounting bolts with thespecial tools to specification.

Tightening torque:A: 100 Nm (10 rn-kq, 72 ft-Ib)B: 60 Nm (6.0 rn- kg, 43 ft·lb)

Tighten the bolt to A to properly seatthe primary sheave on the crankshaft.Loosen the bolt, then torque it to B,the final torque.

V-BELT

Removal1. Turn the secondary sliding sheave clock­

wise, and push it towards the chain case.2. While holding the sliding sheave in this

compressed position, remove the V-beltfrom the secondary sheave. Then,remove it from the primary sheave.

1. New 2. Wear limit

12 —

1. V-belt length

ReassemblyWhen reassembly the V-belt, reverse theremoval procedure. Note the following points:

1. Before installing the V-belt, clean theoil off the fixed sheaves and slidingsheaves using a lacquer thinner.

. EXPLODED DIAGRAMCARBURETOR

t1— Starter Jet

®a~

~-~

~ Overflow Pipe

@— Float Need~

~

<~

——-…….~

~ ~/6:1.,/

Main Jet

~’1®

O-R;ng —0 itMain Jetcover~

)i~

Slow Jet ——Q,CarburetorAssembly

-13 —

INTAKE

Pulse Pipe

Fuel Pump

-14

Primer Pump

Intake Silencer

b ret o r Boot’ —-Car u

The bolt head must be insertedas shown.

PRIMARY SHEAVE

Apply to bottomfour threads orthread-lockinqcompound suchas» LOCTITE #640with PRIMER T».

Belt width:New: 31.6 mm (1.24 in)

Wear limit: 28 mm (1.10 in)

Bushing clearance:0.25 mm (0.01 in)

Be sure the «X» on the sheave capaligns with «X» on the spider.

14 Nm (1.4 m-kg, 10 ft-Ib)

I Bushing clearance:I 0.25 mm (0.01 in)

Use molybdenum sprays

liberally on the weights.

……~ Oiling Point

~ Greasing point

……. X No oiling or greasing is allowed

-15 —

1. Spider

2. Plain washer3. Roller4. Bushing5. Primary sheave cap6. Fixed sheave

7. Fixed sheave stopper8. V-belt

9. Sliding sheave10. Slider11. Bush12. Plain washer13. Weight

DRIVE AXLE

Drive Sprocket

Axle Nut ftolbl!I (8 a m·kg, 5880 Nm .

-16-

SKI

SLIDE RAIL

-18 —

SUSPENSION WHEELS

-19-

BUMPER

Protector 4

Front Bumper 3

Flap

~~~’itD Front Bumper

Bind Screw (@ (@6——~ Bumper End

>~. »..’ r.

Spring Nut

r Flanqe Bolt

/

-20-

ELECTRICAL COMPONENTS

Throttle Lever

LeverHolder (R)

21

GENERAL SPECIFICATIONS

SPECIFICATIONS

Model BR250TJ

Model Code Number: 8Y1

Frame Starting Number: 8Y1-000101

Engine Starting Number: 8Y1-000101

Dimensions:Overall Length 2,925 mm (115.2 in)Overall Width 950 mm ( 37.4 in)Overall Height 1,115mm( 43.9 in)

Weight:With Oil and Full Fuel Tank 184 kg (406 Ib)

Engine:Engine Type Two-strokeCooling System Axial fan air cooledCylinder Arrangement Forward-incline, single cylinderDisplacement 246 cm ‘ (15.0 cu.in)Bore x Stroke 70 x 64 mm (2.76 x 2.52 in)Compression Ratio 6.1 : 1Start ing System Recoil hand starter

Lubrication System: YAMAHA Autolube system

Engine Oil:Type YAMALUBE 2-cycle oilTank Capacity 1.75 L (1.54 Imp qt, 1.85 US qt)

—~—_._——_..—

Transmission Oil:Type Gear oil API «GL-3″ (SAE # 75′»» # 80)

I Capacity 0.20 L (0.18 Imp qt, 0.21 US qt)

Fuel:Type Regular gasolineTank Capacity 15.0 L (3.3 Imp gal, 4.0 US gal)

Carburetor: I

TypeI

BD32-28Manufacturer I KEIHIN

Spark Plug: i

ITypei

BR8HSManufacturer

INGK

Gap 0.6′»» 0.7 mm (0.024′»» 0.028 in)

Transmission:Primary Reduction System V-BeltPrimary Reduction Ratio 3.5 : 1 «» 1 : 1Clutch type Automatic centrifugal engagementSecondary Reduction System Chain (#40K-1)Secondary Reduction Ratio 24/11 (2.18)Reverse System No

Chassis:Frame Type Monocock (Steel)Caster 25°Ski Stance 750 mm (29.5 in)

-22-

Model BR250TJ

Suspension:Front Suspension Type Leaf spring, oil damper

Rear Suspension Type Slide rail

Track:Track Type Internal drive type

Track Width 381 mm (15.0 in)Length on Ground ‘,110 mm (43.7 in)Track Deflection 40′» 50 mm {lo57- ‘.97 in)/10 kg (22 Ib)

Brake:Brake Type Disc brake (Caliper swing type)

Operation Left hand

Electrical:Ignition System C.D.1. ignitionGenerator System Flywheel magnetoBattery Type -Battery Capacity —

Headlight:Type Halogen light

Bulb Wattage x Pes:Headlight GO/55W x 1Tail/Brake Light 8W/23W x 1Meter Light 3AW x 1

-23

a

MAINTENANCE SPECIFICATIONS

Engine

Model

Cylinder head:Volume (With spark plug)Warp Limit

Cylinder:MaterialBore SizeTaper LimitOut-of-Round Limit

Piston:Piston Size (D)/Measuring Point (a)

o/~~-

D ‘7

Clearance between Piston & CylinderOversize 1st

2nd3rd4th

Piston Pin Hole Off- Set

BR250TJ

33.1 — 33.7 cm’ (2.02 — 2.06 cu.in)

Aluminum alloy with special cast iron sleeve70.000 — 70.020 mm (2.756 «»‘ 2.757 in)< 0.05 mm (0.0020 in) >< 0.01 mm (0.0004 in) >

69.950 — 69.980 mm (2.754 — 2.755 in)/10 mm (0.394 in)

0.045′» 0.050 mm (0.0018′» 0.0020 in)72.25 mm (2.845 in)72.50 mm (2.854 in)

1.0 mm (0.04 in) Exhaust side

Piston Pin:Outside Diameter x Length

Piston Ring:Sectional Sketch

End Gap (Installed)

Side Clearance

Coating

Top Ring

2nd Ring

Top Ring2nd RingTop Ring2nd RingTop Ring2nd Ring

…

24-

18 x 55 mm (0.71 x 2.71 in)» — ..» _._ _-.. —-.—..——i

KeystoneB 1.2 mm (0.047 in)T:::: 2.8 mm (0.110 in)PlainB:::: 1.2 mm (0.047 in)T 2.8 mm (0.110 in)0.20 — 0.40 mm (0.0079′» 0.00157 in)0.20 — 0.40 mm (0.0079 — 0.00157 in)0.03 — 0.07 mm (0.0008 — 0.0024 in)0.02″» 0.06 mm (0.0008″» 0.0024 in)ParkerizingParkerizing

Model

Crankshaft:Crank Width»F»Assembly Width»AnConnecti ng Rod Small End Free Play «B»Connecting Rod Big End Clearance «C»Crankshaft Deflection «0»:

Measuring Point — 1

-2-3

4Inside Diameter for Crank Pin

BR250TJ

55.95 — 56.00 mm (2.202 — 2.362 in)2.0 mm (0.080 in)0.25″‘» 0.75 mm (0.010′» 0.030 in)

0.02 mm (0.0008 in)0.02 mm (0.0008 in)

23.900 — 23.915 mm (0.941 — 0.942 in)

100 mm /3.9 in) 80 mm (3.1 in)I

~ &Jl ~ -1- Il

LlH [.’—‘ :=J R/H

~ JL :/

(M.J.)(M.AJ.l

(P.J.)(P.AJ.)(AS.)(Pw.J.)

Big End Bearing:Type

Small End Bearing:Type

rank Pin:Outside Dia.

Crank Bearing:Type Quantity:

Crankshaft LeftCrankshaft CenterCrankshaft Right

Crank Oil Seal:Type/Size Quantity:

Crankshaft LeftCrankshaft CenterCrankshaft Right

Connecting Rod:Parallel Limit

Intake:Type

Carburetor:Type/Manufacturer Quantity1.0. MarkMain JetMain Air JetJet NeedleNeedle JetPilot JetPilot Air JetAir ScrewPower Jet

25-

. __ .__.._…._—_._…_—

Needle bearing

23.987′» 24.000 mm (0.9444′» 0.9449 in)

#6306

#6305

S03-30, 72, 71, GS

505-25/ 48, 8/ GS

< 0.05 mm (0.0020 in) >

Piston valve

B032-28/KEIH IN80JOO#105

#78#1001 and 1/4 turns out

Model BR250TJ

Power Air Jet (Pw.A.J.) -Starter Jet (G.S.) # 120Valve Seat Size (V.S.) ¢ 1.4

Idling Engine Speed 1,100 ± 100 r/minFloat Arm Height (F.H.) 15 ± 2.0 mm (a.59 ± O.OS in)

High Altitude Tuning

~-30°C -20°C -10°C O°C 10°C 20°C

Altitude (-22°F) (_4°F) (14°F) (32.oF) (50°F) (6SoF)

#105Sea level ~

#102

-600 m #105(2,000 ftl #102

«»»1,200 m #105(4,000 ft] #102

-1,800 m #102(6,000 ft) #100

-2,400 m #102(8,000 ttl #100

-3,000 m #100(10,000 ftl #98

Fuel Pump:Type/Manufacturer Quantity Diaphragm type/KEIHIN/l

Oil Pump:Color Code Pink

Plunger Diameter 5.5 mm (0.16 in)

Minimum Stroke 0.20 — 0.25 mm (0.0079 — 0.0098 in)Maximum Stroke 1.65 — 1.87 mm (O.0650 — 0.0736 in)Reduction Ratio 1/45

Minimum Output (at 200 stroke) 0.95 — 1.19 cm ‘(0.033 — 0.042 Imp oz, 0.032 — 0.040 US oz)

Maximum Output (at 200 stroke)I 7.S4 — 8.S9 crrr’

(0.276 — 0.313 Imp oz, 0.265 — 0.301 US oz)Pump Cable Adjustment 24″»‘» 26 mm (0.94 — 1.02 in)

::d:::~~Cool ing System:

Cooling Fan Belt Tension —

Crankcase Tightening Sequence: 1 710 35 00 0

— —

0 0

8

~2 0 4.

-26-

Model

Transmission:TypeRangeof Ratio~ngagement RPMShift RPMSheave Center Distance»A»Sheave Offset «B»

V-belt:

Part No.Outside CircumferenceWidth IIA»

Wear Limit «B»

BR250TJ

V-belt Automatic3.5 : 1 — 1 : 1Approx. 2,800 r/minApprox. 5,700 r/min266 mm (10.47 in)11 mm (0.433 in)

8F2-17641-001,099 mm (43.26 in)31.6 mm (1.24 in)28.0 mm (1.10 in)

Primary Sheave Spring:Part No.Color CodeOutside Dia. x Wire Dia. ‘Pre-load/Set LengthSpring RateNo. of CoilsFree Length

Primary Sheave Weight Arm:Part No.Weight x QuantityAdditional Weight typeHole Position

27 —

90501-553A5Gold-Red55.0 x 5.5 mm (2.165 x 0.217 in)14 kg/61.5 mm (2.42 in)2.64 kg/mm4.966.8 mm (2.63 in)

8VO-17632·0046.1 9 x 3 pesNoneNone

Model

Secondary Sheave Spring:Part No.Color CodeOutside Dia. x Wire Dia.Twist AngleHole Position (Sheave Side) *

(Spring Seat Side)**

8R250TJ

90580-40080None50 x 4.0 mm (1.968 x 0.157 in)160

0

*

Spring RateNo. of CoilsFree LengthColor CodeTorque Cam Angle

Drive Chain:TypeNo. of LinksFree Play

Optional Sprocket:Drive SprocketDriven Sprocket

Track:Part No.Width x LengthPitch x No. of LinksThickness /IA»Height «8»

o

o

**

183 kq-rnrn/deq (15.9 lb-in/deq)9.9105 mm (4.13 in)

#40-1448′»‘» 15 mm (0.32′»‘» 0.59 in)

11,12,13,1421,22,23,24

8XO-47110-00381 x 3,456 mm (15.0 x 136.1 in)64 mm (2.52 in) x 545.5 mm (0.22 in)15.5 mm (0.61 in)

Deflection at 10 kg (22 lb)

-28-

40 — 50 mm (1.57 -. 1.97 in)

Model

Track Suspension:Front TravelRear Travel

Front Suspension Spring:Spring RateWire Dia.

Rear Suspension Spring:Spring RateWire Dia.

Suspension Setting Position:Stopper Band Hole Position

Shock Absorber:Damping Force (Extension)

Damping Force (Compression)

Slide Runner:Thickness IIA»

Wear Limit «B»

FrontRear

FrontRearFrontRear

BR250TJ

102 mm (4.02 in)76 mm (2.99 in)

305 kq/mrn (17,080 Ib!in)!deg9.5 mm (0.37 in)

318.3 kq/rnrn (17,825 Ib!in)!deg10 mm (0.39 in)

No.2

48 kg (106 Ib)!0.3 rn/s48 kg (106 Ib}!OA rn/s45 kg ( 99 Ib)!0.3 rn/s45 kg ( 99 Ib)!0.3 rn/s

15 mm (0.59 in)10 mm (0.39 in)

Track Drive Sprocket Wheel:MaterialNo. on Teeth

Rear Guide Wheel:MaterialOutside Dia.

Brake:Pad Thickness»A»Wear Limit «B»

— 29-

Polyethylene7

Alminium191 mm (7.52 in)

7.3 mm (0.287 in)1.0 mm (0.039 in)

Model BR250TJ

Padto Disc ClearanceDisc Outside Dia.Disc ThicknessBrake Lever Free Play*

Chassis

0.2′» 1.0 mm (0.008′» 0.039 in)182 mm (7.16 in)3.2 rnrn (0.13 in)3.0′» 8.0 mm (0.12 — 0.32 in)

Model

Frame:Frame MaterialSeat HeightLuggage Box Location

SteeringSteering AngleSteering Angle

Ski AlignmentSki Toe-out Size

Distance II A»

(Right)(Left)

BR250TJ

Steel

Between seat and shroud

55.0 mm (2.17 in)55.0 mm (2.17 in)

Toe-out0″»» 15 mm (0′» 0.59 in)

1,960 mm (77.0 in)

— 30

Electrical

Model BR250TJ

Voltage:

Ignition System:Ignition TimingAdvanced TimingAdvancer Type

(B.T.D.C.)(B.T.D.C.)

12V

1.6 mm (0.063 in) 16° at 5,500 r/min

Ir—-+—-+—+—J—-+—-+-J-+—+—-+—J—-+——t-i—+—Ji

2 If—-+—t— —j——t— —t-.-+—t—+—t—j—t—I—-r—j—i—i

II

IIi

!—-f—f——-r—+—+—+—l—j—-+- +…_-j-._-+—t—+—t—+

Io II—j-.-+—~__+-_l_-+—+—t—+—+—+_—+-_+_-+___+-+____i

I /VOJc’Et=c:o:2cE:

_…. -_. —_._—_._._._—

CDI:Model/ManufacturerPickup Coil ResistanceColor CodeCharge Coil ResistanceColor CodeCOl Unit Model/Manufacturer

2 3 4 5 6 7

Engine Speed ( x 103 r/rnln)

F8R4/YAMAHA20n ± 10% at 20°C (68°F)(W/R B)426[2 ± 10% at 20°C (68°F)(Br B)

80F/YAMAHA

8 9

Ignition Coil:Model/ManufacturerMinimum Spark GapPrimary Winding ResistanceSecondary Winding Resistance

F6T411/MITSUBISH I11 mm (0,43 in) at 3,000 r/min1.0n ± 15% at 20°C (68°F)5.9 kn ± 15% at 20°C (68

0F)

Ignition Coil:Model/ManufacturerMinimum Spark GapPrimary Winding ResistanceSecondary Winding Resistance

Spark Plug Cap:TypeModel/ManufacturerResistance

Resin

L05E/NGK5.0 k[2 ± 25%

Flywheel Magneto:Model/ManufacturerCharging Current-Day

Charging Current-Night

(Min.)(Max.)(Min.)(Max.)

F8R4/YAMAHA

— 31-

Model BR250TJ

Charging Coil Resistance -Color Code -Lighting Voltage (Min.) 11.8 V/3,000 r/min

(Max.) -Lighting Coil Resistance 0.23Q ± 20% at 20°C (68°F)Color Code Y-B

30 :

> IQ) IOJ ,~0 20>OJS…..s: ………..OJ

~:.J 10~

f

-~-

2 3 4 5 6 7 8 9

Engine Speed ( x 10 3 r/minl

!I

Coil Resistance for Grip Warmer -. Color Code

-_.

Voltage Regulator:Type A.C. TypeModel/Manufacturer TR1Z·50/HITACHI,58516B/TOSHIBANo Load Regulated Voltage 13.3 «‘14.3 V

— 32-

Tightening torque

Tread sizeTightening torque

RemarksPart to be tightenedNm m·kg ft·lb

[Engine]Spark plug M14 x P1.25 28 2.8 20Cylinder head (bolt) M8 x P1.25 20 2.0 14

Cylinder head (nut) M10 x P1.25 25 2.5 18

Flywheel magneto M16 x P1.9 73 7.3 53Crankcase upper and lower

First: M8 x P1.25 10 1.0 7.2Final: 25 2.5 18

Tightening sequence

fOl J6l J6l A J—r~@

~I ~ I~Ir-

.r==:Q) ~?~ ~(c5’L .~

IL~ 1 ~ ~~)j@

~ \gF=iQJf-L

Crankcase and gear unit M8 x P1.25 25 2.5 18Oil pump and gear unit M5 x PO.8 8 0.8 5.8 with screw lockStarter pulley M8 x P1.25 15 1.5 11Crankcase and engine bracket M8 x P1.25 25 2.5 18

[Drive and track suspension]Primary sliding sheave and cap M6 x P1.0 11 1.1 8.0Installation of primary sheave

Initial: UNF 1/2″ 100 10 72 Use motor oil60 6.0 43 Loosen once and

retighten.Installation of secondary sheave M12 x P1.25 40 4.0 29Bearing housing M8 x Pl.25 23 2.3 17Secondary shaft and bearing collar Socket screw 6 0.6 4.3Brake cliper and housing chain M10 x P1.25 50 5.0 36Installation of drive chain sprocket M20 x Pl.25 60 6.0 43 BoltInstallation of driven chain sprocket M6 x Pl.0

I5.8 0.58 4.2 Bolt

Chain housing and frame M8 x P1.25 23 2.3 17Installation of front axle L.H. M22 x Pl.0 85 8.5 61

and bearingFront axle housing and frame M8 x P1.25 23 2.3 17Front pivot shaft M10 x P1.25 65 6.5 47Rear pivot shaft M10 x P1.25 65 6.5 47Guide wheel shaft M12xP1.25 80 8.0 58Sliding runner M6 x Pl.0 2.5 0.25 1.7Lower end bracket M8 x P1.25 20 2.0 14Lower end bracket and absorber M6 x P1.0 2 0.2 1.4 Loctite@Front arm 1 and 2 M10 x P1.25 45 4.5 32Installation of ski M10 x P1.25 45 4.5 32

[Chassis]Engine mounting bolt M10 x P1.25 52 5.2 37Ski runner M8 x P1.25 14 1.4 10 Use self-locking

nut and Loctite@

-33-

Part to be tightenedTightening torque

RemarksThread sizeNm rn-kq ft-lb

Steering column and gate M8 x P1.25 13.7 1.37 10 Use lock washerSteering tie rod adjusting nut M10 x P1.25 25 2.5 18 Loctite®Steering lower bracket M8 x P1.25 13.7 1.37 10 Use lock washerInstallation of steering column 1,2 M8 x P1.25 13.7 1.37 10Steering relay adjusting nut M10 x P1.25 25 2.5 18 Loctite®

GENERAL TORQUE SPECIFICATIONSThis chart specifies torque for standard fas­teners with standard I.S.O. pitch threads.

Torque specifications for special componentsor assemblies are included in the applicablesections of this book. To avoid warpage,

General torqueA B specifications

(Nut) lBoltl Nm rn-kq

10 mm 6 mm 6 0.6

12 mm 15 1.5

14 mm 30 3.0

55 5.5

85

130

CONVERSION TABLES

METRIC TO INCH SYSTEM

Known Multiplier Result

m-kg 7.233 ft-Ibrn-kq 86.80 in-Ib

crn-kq 0.0723 ft-Ibem-kg 0.8680 in-Ib

kg 2.205 Ibg 0.03527 02

km/lit 2.352 mpgkm/hr 0.6214 mphkm 0.6214 mim 3.281 ftm 1.094 ydcm 0.3937 inmm 0.03937 in

cc (cm3) 0.03382 oz (U.S. liq)

cc (crn») 0.06102 cu.inlit (l iter) 2.1134 pt (U.S. liq)lit (liter) 1.057 qt (U.S. liq)lit (l iter) 0.2642 gal (U.S. liq)

kg/mm 56.007 Ib/inkq/crrr’ 14.2234 psi (lb/in2

)

Centigrade (0C) 9/5 (C) + 32 Fahrenheit lO F)

-34-

tighten multi-fastener assemblies in a criss­cross fashion, in progressive stages, until fulltorque is reached. Unless otherwise specified,torque specifications call for clean, dry

threads. Components should be at roomtemperature.

INCH TO METRIC SYSTEM

Known Multipl ier lesult

ft-Ib 0.13826 m-kqln-Ib 0.01152 m-kqft-Ib 13.831 em-kginIb 1.1521 em-kg

Ib 0.4535 kgoz 28.352 9

mpg 0.4252 km/litmph 1.609 krn/hrmi 1.609 kmft 0.3048 myd 0.9141 min 2.54 emin 25.4 mm

oz (U.S. liq) 29.57 ee (em3)

cu.in «16.387 ce (crn»)pt (U.S. liq) 0.4732 lit (liter)qt (U.S. liq] 0.9461 lit (liter)gal (U.S. liq) 3.785 lit (liter)

Ib/in 0.017855 kg/mmpsi (lb/in? ) 0.07031 kg/cm 2

Fahrenheit (0 F) 5/9 (F) — 32 Centigrade (C)

CABLE ROUTING (1)

Throttle wire

Band Hold the engine stop switch lead wire

Clamp

Wire harness assembly

Clamp

— 35-

Brake wire assembtv

Band Hold both beam and brake lightswitch lead wires

Clamp Clamp the hose

«C

CABLE ROUTING (2)

A-View

Brake light switch lead wire

Beam switch lead wire

T.O.R.S. lead wire

Grommet

Band — Clamp after gatheringthe terminals

Clamp

C.D.I. unit

To flywheel magneto

Clamp — Install together with boltssecuring crankcases 1 and 2

E-View

t To head lamp

Pipe joint

T.O.R.S. lead wire

Wire harness assembly

Grommet

36-

Body earth

CABLE ROUTING (3)

B·View

Recovery tank

Protector pipe

Fuel level gauge

To taillight …

Clip

Pulse pipe

Breather pipe

Route under the fuel tank

Protector pipe keep the hoseaway from the chain housing

c-vlew

Pump wire assembly

pump assembly

Clip

From fuel tank

Autolube pump assembly

37 —

CABLE ROUTING (4)

Starter lever installation

Clamp

— 38-

CABLE ROUTING (5)

Recovery tank installation

Tank fitting band

Instrument panel

39 —

Hook

Panel frame

WIRING DIAGRAM

G/Y GreenIYellowB/W….•.Black/WhiteBIY …•••Black/YellowW/R White/Red

Spark plug

~

COLOR CODE

B . . .. . .BlackL BlueG …•…Greeno OrangeY YellowBr Brown

C.D.I. Unit

B/W

._ ._~,,~__ _ __ H Tail/Brake light

EL= . ! r+le:~:v

~1

Voltageregulator

Main switch

GIYI~G/YLlWJ-L I

Headlight

c=tl~G

. Y B B. 0 y I I I ,

Headlight beamswitch

Engine stop switchI i i

Brake Iight switch

J~oJ

• YAMAHA 1~,~:rOR CO.,LTD.

PRINTED IN U.S.A.

YAMAHASUPPLEMENTARYSERVICE MANUAL

880-28197-10

BR250TVSUPPLEMENTARY SERVICE MANUAL

©1994 by Yamaha Motor Corporatlon, U.S.A.1st Editionl May 1994

All rights reserved. Any reprinting orunauthorized use without the written

permission of Yamaha Motor Corporation,U.S.A. is expressly prohibited.

Printed in U.S.A.PIN LlT-21618-01-61

FOREWORDThis Supplementary Service Manual has beenprepared to introduce new service and new datafor the BR250TV. For complete information onservice procedures, it is necessary to use thisSupplementary Service Manual together with fol­lowing manual:

BR250F SERVICE MANUAL:

8R4-28197-10

BR250G SERVICE MANUAL:

8V6-28197-20

BR250H

SUPPLEMENTARY SERVICE MANUAL:

8X4-28197-20BR250T(J)

SUPPLEMENTARY SERVICE MANUAL:

8Y1-28197-70

BR250TSUPPLEMENTARY SERVICE MANUAL:

81X-28197-25

HOW TO USE THIS MANUAL

Particularly important information is distin­guished inthismanual by the following notations:

&The Safety Alert Symbol means ATTENTION!BECOME ALERT! YOUR SAFETY IS INVOLVED!

A WARNING

Failure to follow WARNING instructions couldresult in severe or death to the machineoperator, a bystander, or a person inspecting orrepairing the machine.

A CAUTION indicates special precautions thatmust be taken to avoid damage to the machine.

NOTE:A NOTE provides key information to makeprocedures easier or clearer.

CD ®

II~~~I~I II:grl~1@ @

CHAS .J.- IP~:RIClDI® ®

IENGI «»»»»»» IICOOLI :I: I@(j) ®

ICARsl ‘ill IELECII:JI® @

ISPEclo—l IOPTlol®

rol@

B@

I~~I®

~@

§@>

[l:]@

[ij]@ @

1a C§JI

® ®) @

1 1 1m ~ ~

@ @ ®

~ ~ ~

OE031

ILLUSTRATED SYMBOLS

(Refer to the illustration)

Illustrated symbols CD to @ are designed asthumb tabs to indicate the chapter’s number andcontent.CD General information® Periodic inspection and adjustment@ Chassis@ Power train® Engine overhaul® Cooling system(j) Carburetion® Electrical® Specifications@ Optional kit

Illustrated symbols ® to @ are used to identifythe specifications which appear.® Filling fluid@ Lubricant@ Tightening® Wear limit, clearance@ Engine speed@ Special tool@n,V,A

Illustrated symbols @ to ® in the exploded dia­gram indicate grade of lubricant and location oflubrication point.@ Apply locking agent (LOCTITE®)@ Apply Yamabond No.5®® Apply engine oil®) Apply gear oil@ Apply molybdenum disulfide oil@ Apply wheel bearing grease@ Apply low-temperature lithium-soap base grease® Apply molybdenum disulfide grease

CONTENTS

GENERAL INFORMATION 1

MACHINE IDENTIFICATION 1

FRAME SERIAL NUMBER 1ENGINE SERIAL NUMBER 1

CHASSiS 2FUEL SUB TANK 2JOB INSTRUCTION CHART 3

ELECTRiCAL 4

CIRCUIT DIAGRAM 4ELECTRICAL COMPONENT 6IGNITION SYSTEM 7

CIRCUIT DIAGRAM 7TROUBLESHOOTING 8SPARK PLUG CAP 9IGNITION COIL 9

SOURCE COIL 9

SPARK PLUG 10

THROTILE OVERRIDE SYSTEM (T.O.R.S.) 10HANDLEBAR SWITCH (RIGHT) 11CARBURETOR SWITCH 11MAIN SWITCH 12

LIGHTING SYSTEM 13CIRCUIT DIAGRAM 13TROUBLESHOOTING 14

BULB (S) 15HEADLIGHT BEAM SWITCH 15

SPECIFICATIONS 16GENERAL SPECIFICATIONS 16

MAINTENANCE SPECIFICATIONS 18

ENGINE 18POWER TRAIN 22CHASSiS 26

ELECTRICAL 27GENERAL TORQUE SPECIFICATIONS 28CABLE ROUTING 29

MACHINE IDENTIFICATION II~~~I~I1E001

GENERALINFORMATION

MACHINE IDENTIFICATIONFRAME SERIAL NUMBERThe frame serial number CD is located on theright-hand side of the frame (just below thefront of the seat).

ENGINE SERIAL NUMBERThe engine serial number CD is located on theright-hand side of the crankcase.

NOTE: _

The first three digits of these numbers are formodel identification: the remaining digits are theunit production number.

Starting Serial Number:BR250TV 8BD-008101

NOTE: _

Designs and specifications are subject to changewithout notice.

-1-

FUEL SUB TANK

-2-

JOB INSTRUCTION CHART

FUEL SUB TANK ICHASI~IOrder Job name/Part name Q’ty Remarks

Removal of fuel sub tank Remove the parts in the order in which theyFuel are listed.Brake cable Extract the fuel from the fuel sub tank usi n9 a

pump.1 Oil tank cap 12 Screw 43 Nut 14 Bolt 45 Plate 2

6 Clamp 2 Refer to the «CABLE ROUTING» section.7 Fuel suction hose 18 Breather hose 1 NOTE:

Unclamp and remove the breather hose from

the fuel sub tank.

9 Fuel level hose 1 NOTE:Disconnect the fuel level hose connected tothe upper part of the fuel sub tank, then raise

the tank so that the other fuel level hose, the

one connected to the lower part of the tank

can be disconnected.

10 Fuel sub tank 1Reverse the removal procedure for installa-tion.

-3-

:-:-__C:.:I, __R.CUIT DIAGRAM

ELECTRICALCIRCUIT DIAGRAM

L

.~~: ‘

:» •, 1-·

L G/Y

L

L

o

-4-

G) Ignition coil® Spark plug® Throttle switch@ Carburetor switch® Main switch® «ENGINE STOP» switch(j) C.D.I. unit® C.D.1. magneto® Speedometer Iight**

COLOR CODE

CIRCUIT DIAGRAM

<iQ) Brake light switch® Tail/Brake light@ Headlight beam switch@ Headlight@ Voltage regulator@ Thumb warmer*@ Grip warmer*® Grip warmer switch** Option** BR250T: Standard equipment

BR250TS: Option

B Black 0 Orange W/R White/Red

L Blue R Red Y/B Yellow/Black

Br Brown Y Yellow Y/R Yellow/Red

Ch Chocolate B/W Black/White GIY GreenIYellow

G Green BIY Black/Yellow

1 13

11

®

50mm(2.0in) 30mm(1.2in)

-5-

NOTE:

• Specified hole should be drilled for the»Grip warmer switch» installation.

• Refer to the illustration ® for locationand size.

ELEC!RICAL COMPONENTCD Mam switch® IJENGINE STOpIJ .I§\ switch\3J Throttle switch@ Headlight beam switch® Brake light switch® Wire harness(J) Vol~age regulator® Ignition coil® C.D.1. unit

ELECTRICAL COMPONENT IELEC I0 I

-6-

IGNITION SYSTEMCIRCUIT DIAGRAMCD Ignition coil® Spark plug® Throttle switcho Carburetor switch® Main switch

IGNITION SYSTEM IELECI0 I

® «ENGINE STOP» .0′ CD » switch\IJ . .. Unit

® C.D.I. magneto

-7-

IGNITION SYSTEM IELEC I0 I8E021

TROUBLESHOOTING

NO SPARK OR WEAK SPARK.

ICheck the spark plug gap.

JL OK

iCheck the spark plug cap resistance.

ICheck the ignition coil resistance.

ICheck the stator coil.

Check the IIENGINE STOP» switch, throttle

switch, carburetor switch and main switch.

~OK

Correct connection and/or replace C.D.1. unit.

-8-

OUT OF SPECIFICATION

IRepair or replace the spark plug.

OUT OF SPECIFICATION

IReplace the spark plug cap.

OUT OF SPECIFICATION

IReplace the ignition coil.

FAULTY

IReplace the stator coil.

FAULTY

Replace the handlebar switch (right),

carburetor switch and/or main switch.

IGNITION SYSTEM

8E041

SPARK PLUG CAP1. Remove:

• Spark plug cap2. Connect:

• Pocket tester(to spark plug cap)

3. Measure:

• Spark plug cap resistance

[::J11 Spark plug cap resistance:~ 5 k11 at 200 e (68°F)

Primary coil resistance:0.411 ± 20% at 20 0 e (68°F)

Secondary coil resistance:7.1 kn ± 20% at 200e (68°F)

8E051

IGNITION COIL1. Disconnect:

• Ignition coil lead (Orange)

• Spark plug lead2. Connect:

• Pocket tester(to ignition coil and spark plug lead)

3. Measure:

• Primary coil resistance CD• Secondary coil resistance ®

8E061

SOURCE COIL1. Disconnect:

• C.D.I. magneto lead and coupler (Brown,Black)

2. Connect:

• Pocket tester(to C.D.1. magneto lead and coupler)

3. Measure:

• Source coil/pulser coil resistanceOut of specification-efleplace.

Source coil resistance: CD(Brown — Black)

275 o ± 20% at 200 e (68°F)

Pulser coil resistance: ®(White/Red — Black)

20 11 ± 20% at 20 0 e (68°F)

-9-

IGNITION SYSTEM

377000

8E031

SPARK PLUG1. Remove:

• Spark plugs2. Check:

• Spark plug

Standard spark plug:BR9ES (NGK)

Spark plug gap:0.6 — 0.7 mm (O.024 — 0.028 in)

THROTTLE OVERRIDE SYSTEM (T.O.R.S.)The ignition is turned off by the following switch­ing functions when the throttle system fails.

~AJ Idle &1 ~J

Switchor Run Trouble

startingThrottle OFF ON OFFswitch

CarburetorON OFF OFFswitch

Engine RUN RUN STOP

<D Carburetor switch® Throttle switch® Throttlle cable@ Throttle stop screw@1I0N»(6) IIOFF»

c

816-«\12

-10-

IGNITION SYSTEM IELECI0 I8E071

HANDLEBAR SWITCH (RIGHT)»ENGINE STOP» switch and throttle switch

1. Disconnect:• Handlebar switch (riqhtl.coupler G)

2. Connect:• Pocket tester (90890-03112, YU-03112)

3. Check:

• «ENGINE STOP» switch continuityFaultv-efteplace.

Switch position Good condition

RUN (pull) x

OFF (push) 0

0: Continuity x : No continuity

4. Check:

• Throttle switch continuityFauIty-:)Replace.

Throttle switchGood condition

position

Throttle lever is 0operated.

Throttle lever is notoperated.

x

8E08l

CARBURETOR SWITCH1. Disconnect:

• Carburetor switch lead2. Connect:

• Pocket tester3. Check:

• Carburetor switch continuityFaultv-s Replace.

Carburetor switchGood condition

position

Throttle lever is xoperated.

Throttle lever is not 0operated.

-~+I () \:$I (

Ir ‘

oB B/YI I

-11-

0: Continuity

0: Continuity

x: No continuity

x : No continuity

IGNITION SYSTEM

aE101

MAIN SWITCH1. Disconnect:

• Main switch coupler CD2. Connect:

• Pocket tester3. Check:

• Main switch continuityFaulty ~ Replace.

Switch position Good condition

OFF x

ON 0

-12-

o : Continuity x : No continuity

LIGHTING SYSTEMCIRCUIT DIAGRAM® C.D.I. magneto® Speedometer light@) Brake light switch® Tail/brake light

@ Headlight beam switch@ Headlight@ Voltage regulator

L

L .~ I

Hi , ,

f l- L I

@Y G L G/Y

®

-13-

— —

LIGHTING SYSTEM IELEC I0 I

8E141

TROUBLESHOOTING

HEADLIGHT, TAIL LIGHT AND/OR METER LIGHT DO NOT COME ON.

ICheck the bulbts),

JL OK

Check the headlight beam switch and lightingcoil.

Correct connection and/or replace the voltageregulator.

-14-

NO CONTINUITY

IReplace the bulbts).

FAULTY

Replace the headlight beam switch and/or stator coif.

®

©

LIGHTING SYSTEM

BULB (S)1. Remove:

• Headlight bulb• Tail/brake light bulb• Meter light bulb

2. Connect:

• Pocket tester(to bulb terminals)

A WARNING

Keep flammable products and your hands awayfrom the bulb while it is on; it will be hot. Do nottouch the bulb until it cools down.

® Headlight© Meter light

3. Check:

• Bulb(s)

(fi)Tail/brake light

®

Terminal Good condition

CD-® 0

CD-@ 0

o :Continuity

HEADLIGHT BEAM SWITCH1. Disconnect:

• Headlight beam switch coupler2. Connect:

• Pocket tester(to headlight beam switch coupler)

3. Check:• Headlight beam switch continuity

Faultv-efteplace.

Switch ®Good (fi) Goodposition condition condition

HI x 0LO 0 x

-15-

0: Continuity x: No continuity

GENERAL SPECIFICATIONS ISPECIa-ISPECIFICATIONS

GENERAL SPECIFICATIONS

Model BR250T BR250TS

Model code number: 8BD2 8BC2

Frame & Engine starting number: 8BD-008l0l 8BC-001101

Dimensions:Overall length 2,945 mm (115.9 in) 2,425 mm (95.5 in)Overall width 950 mm (37.4 in) t-Overall height 1,120 mm (44.1 in) 1,100 mm (43.3 in)

Weight: 175 kg (386 Ib) 153 kg (337 Ib)

Model BR250TrrS

Minimum turning radius:Clockwise 3.7 m (12.1 ft)Counterclockwise 3.7 m (12.1 ft)

Engine:Engine type Air cooled 2-strokeInduction system Piston valveCylinder arrangement Forward inclined single cylinderDisplacement 246 ern»Bore x Stroke 70 x 64 mm (2.76 x 2.52 in)Compression ratio 6.1:1Starting system Recoil starter

Lubrication system: Separate Lubrication

Engine oil:Type YAMALUBE 2Tank capacity 1.8 L (1.6 Imp qt, 1.9 US qtl

Drive chain housing oil:Type Gear oil API /lGL-3″ SAE #75 or #80Capacity 0.2 L (0.18 Imp qt, 0.21 US qt)

Fuel:Type Unleaded gasolineTank capacity (main tank) 15 L (3.3 Imp gal, 3.96 US gal)

(sub tank) 9.3 L (2.05 Imp gal, 2.46 US gal)

Carburetor:Type/Quantity BD32-28Manufacturer KEIHIN

Spark plug:Type BR8HSManufacturer NGKGap 0.6 …, 0.7 mm (0.02 …, 0.03 in)

Transmission:Primary reduction system V-beltPrimary reduction ratio 3.5 ‘» 1.0:1Clutch type Automatic centrifugal engagementSecondary reduction system ChainSecondary reduction ratio 24/10 (2.40) (BR250T)

23/12 (1.92) (BR250TS)

-16-

GENERAL SPECIFICATIONS ISPECI 0—1Model BR250T/TS

Chassis:Frame type MonocoqueCaster 25°Ski stance (center to center) 750 mm (29.5 in)

Suspension:Front suspension type Leaf springRear suspension type Slide rail suspension

Track:Track type Internal drive typeTrack width 381 mm (15.0 in)Length on ground 1126 mm (44.3 in)Track deflection mm/l0 kg (22 Ib) 40″, 50 mm (1.6″, 2.0 in)

Brake:Brake type Caliper type disc brakeOperation method Handle lever, left handle operated

Electrical:Ignition system/Manufacturer C.D.I./YAMAHAGenerator system Flywheel magneto

Bulb wattage x Quantity:Headlight 12V 60W/55W x 1 (BR250T)

12V 60W/60W x 1 (BR250TS)Tail/Brake light 12V 8W/23W xlSpeedometer light 12V 3.4W xl

-17-

MAINTENANCE SPECIFICATIONS ISPECI c:r-IMAINTENANCE SPECIFICATIONSENGINE

Model

Cylinder:MaterialBore size<Taper limit><Out-of-Round limit>

Piston:Piston size (D)Measuring point ®

Piston to-Cylinder clearance

BR250T/TS

Aluminum alloy with cast iron sleeve70.00 ‘» 70.02 mm (2.756 ‘» 2.757 in)0.05 mm (0.0020 in)0.01 mm (0.0004 in)

69.955 ‘» 69.960 mm (2.7541 ‘» 2.7543 in)»,,—……, 10 mm (0.4 in)

o J ®7~=*I

D

0.045″, 0.050 mm (0.0018 ‘» 0.0020 in)

Piston ring:Sectional sketch Top ring

2nd ring

End gap (installed): Top ring2nd ring

Side clearance Top ring2nd ring

Coating Top ring2nd ring

KeystoneB= 1.2 mm (0.05 in)T= 2.8 mm (0.11 in)

PlainB= 1.2 mm (0.05 in)T= 2.8 mm (0.11 in)

0.2 ‘» 0.4 mm (0.008 ,.., 0.016 in)0.2 ‘» 0.4 mm (0.008,…, 0.016 in)0.02 ‘» 0.06 mm (0.0008 ‘» 0.0024 in)0.02 ‘» 0.06 mm (0.0008 ‘» 0.0024 in)Chrome plated/ParkerrizingChrome plated/Parkerrizing

-18-

MAINTENANCE SPECIFICATIONS ISPECI 0—1Model BR250TfTS

Crankshaft:Crank width IIA» 55.95 … 56.00 mm (2.203 … 2.205 in)Connectingrod small end free play IIF» 2 mm (0.08 in)Connecting rod big end side clearance «D» 0.25 … 0.75 mm (0.01 … 0.03 in)Crankshaft deflection «C»: C 0.03 mm (0.0012 in)

F…..-.

~~tjo

A

Big end bearing:Type Needle bearing

Small end bearing:Type Needle bearing

Carburetor:Type/Quantity BD32-28/1Manufacturer KEIHINI.D. mark 80J 01Main jet (M.J.) #105Pilot jet (P.J.) #78Pilot screw (P.S.) 1-1/4Throttle valve (Th.V.) T= 1.0/15°Valve seat size (V.S.) 1.4Fuel level (F.L) 13 … 17 mm (0.51 … 0.67 in)Engine idle speed 1,000 … 1,200 r/rnin

Fuel pump:Type DiaphragmManufacturer KEIHIN

Oil pump:Pump cable free play 24 ‘» 26 mm (0.94 ‘» 1.02 in)

-19-

MAINTENANCE SPECIFICATIONS ISPECI 0—1Model I BR250rffS

High altitude settings

~ -30°C -20°C -10°C ooe 10°C 20°C

Altitude (-22°F) (-4°F) (14°F) (32°F) (50°F) (68°F)I I I I I I

.. #1020″, 100 m(0 … 300 ft) #105 (STD) ..

100″, 600 m .. #102

(300 … 2,000 ft) #105 (STD) ..600 … 1,200 m .. #102

(2,000 N 4,000 ft) #105 (STD) ..1,200 ‘» 1,800 m Ill( #100

(4,000 N 6,000 ft) #102 ..1,800 … 2,400 m .. #100

(6,000 «» 8,000 ft) #102 ..2,400 «» 3,000 m #100 ..

(8,000 ‘» 10,000 ftl .. #98

# : Main jet number

-20-

MAINTENANCE SPECIFICATIONS ISPECI0—1Tightening torque:

Part to be tightenedTightening torque

RemarksNm rn-kq ft-lb

Spark plug 28 2.8 20Cylinder head (bolt) 20 2.0 14Cylinder head (nut) 25 2.5 18Flywheel magneto 85 8.5 61Crankcase upper and lower

First: 20 2.0 14 Tighten the bolts inFinal: 25 2.5 18 two stages.

Tightening sequence

1 710 35 00 0

— —

0 0

8~2 0 4

Crankcase and gear unit 25 2.5 18Oil pump and gear unit 8 0.8 5.8 With screw lockStarter pulley 15 1.5 11Crankcase and engine bracket 25 2.5 18

-21-

POWER TRAIN

Model

MAINTENANCE SPECIFICATIONS ISPECI cr—IBR250T/TS

Transmission:TypeRange of ratioEngagement RPM

Shift RPM

Sheave center distance JI A»Sheave offset «B»

,Jiiiiiiiia.. • B

V-Belt:Part numberOutside circumferenceWidth «A»Wear limit «B»

AB

I’

V-belt automatic3.5 «»‘ 1.0:12,900 «»‘ 3,500 r/min (BR250T)2,600″, 3,200r/min (BR250TS)5,600 ‘» 7,200 r/min (BR250T)5,400 «»‘ 6,000 r/rnin (BR250TS)264″»‘ 268 mm (10.4 ,… 10.6 in)8″» 14 mm (0.31 ‘» 0.55 in)

—-

89X-17641-001.095″»‘ 1.103 mm (43.1 .., 43.4 in)31.6 mm (1.24 in)28.0 mm (1.10 in)

Primary sheave spring:Part numberColor codeOutside diameterWire diameterPre-load/Set lengthSpring rateNumber of coilsFree length

Primary sheave weight arm:Part number (with bushing)Weight

Secondary sheave spring:Part numberColor codeOutside diameterWire diameter

III

!II,

«

90501-50654NO PAINTED55 mm (2.2 in)5 mm (0.2 in)15 kg (33 Ib}/61.5 m (2.42 in)24 N/mm (2.4 kg/mm , 134 Ib/in)4.0867.8 mm (2.67 in)

8V8-W176A-0045.7 ± 1 9 (1.61 ±0.04 oz)

90508-40080NO PAINTED50 mm (1.97 in)4 mm (0.16 in)

-22-

Model

Hole positionSheave side-spring seat side(twist angle)Spring rateNumber of coilsFree length

Drive chain:TypeNumber of links

Track:Part numberWidthLengthPitchNumber of links

Suspension setting position:Stopper band hole position

Front

MAINTENANCE SPECIFICATIONS ISPECI0—1BR250TfTS

183 kg/mm9.9105 mm (4.13 in)

DID 40K-144

89X-47110-00381 mm (15.0 in)3,456 mm (136 in)64 mm (2.52 in)54

No.2

-23-

MAINTENANCE SPECIFICATIONS ISPECI0-1Model BR250TffS

Shock absorber: Damping forceFront

Extension 80 kg/0.3 m/sCompression 50 kg/0.3 rn/s

RearExtension 48 kg/0.3 m/sCompression 45 kg/0.3 mls

Slide runner:Thickness 13.5 mm (0.53 in)Wear limit 8.5 mm (0.33 in)

Track sprocket wheel:Material PolyethyleneNumber of teeth 9

Rear guide wheel:Material Aluminum with rubberOutside diameter f2S191 mm (7.5 in)

Brake:Pad thickness 7.3 mm (0.29 in)Pad wear limit 1 mm (0.04 in)Pad to disc clearance 0.2 «» 1.0 mm (0.008 … 0.040 in)Disc th ickness 3.2 mm (0.13 in)Brake lever free play 6 «» 7 mm (0.24 «» 0.28 in)

-24-

MAINTENANCE SPECIFICATIONS ISPECIcr-ITightening torque:

Parts to be tightenedTightening torque

RemarksNm rn-kp ft-lb

Primary sliding sheave and cap 11 1.1 8.0Installation of primary sheave

First: 100 10 72 Tighten the bolts inFinal: 60 6.0 43 two stages. See NOTE.

Installation of secondary sheave 40 4.0 29Bearing housing 23 2.3 17Secondary shaft and bearing collar 6 0.6 4.3Brake caliper and housing chain 50 5.0 36Installation of drive chain sprocket 60 6.0 43 BoltInstallation of driven chain sprocket 5.8 0.58 4.2 BoltChain housing and frame 23 2.3 17Installation of front axle L.H. and bearing 85 8.5 61Front axle housing and frame 23 2.3 17Front pivot shaft 65 6.5 47Rear pivot shaft 65 6.5 47Guide wheel shaft 80 8.0 58Sliding runner 2.5 0.25 1.7Lower end bracket 20 2.0 14Lower end bracket and absorber 2 0.2 1.4 Apply LOCTITE®Front arm 1 and 2 45 4.5 32Installation of ski 45 4.5 32

NOTE: _

Tightening steps:1.Tighten the bolt. 120Nm (12 m • kg, 85 ft· Ib).2. Loosen it completely.3. Retighten it. 60Nm (6.0 m • kg, 43 ft • lb),

-25-

CHASSIS

MAINTENANCE SPECIFICATIONS ISPECI0—1Model BR250TfTS

Frame:Frame material Steel

Steering:Lock to lock angle (left) 24.6° (R Ski), 28.P (L Ski)

(right) 28.10 (R Ski), 24.6° (L Ski)Ski alignment Toe-outToe-out size o «» 6 mm (0 «» 0.24 in)

Ski:Ski material SteelLength 980 mm (38.6 in)Width 120 mm (4.72 in)Thickness 1.6 mm (0.06 in)

Ski suspension:Spring type Leaf spring

Tightening torque:

Parts to be tightenedTightening torque

RemarksNm m-kq ft-lb

Engine mounting bolt 30 3.0 22Ski runner 14 1.4 10Steering column and gate 13.7 1.37 10 Use lock washerSteering tie rod adjusting nut 25 2.5 18 Apply LOCTITE®Steering lower bracket 13.7 1.37 10 Use lock washerInstallation of steering column 1, 2 13.7 1.37 10Steering relay adjusting nut 25 2.5 18 Apply LOCTITE®

-26-

MAINTENANCE SPECIFICATIONS ISPECI 0-19E041

ELECTRICAL

Model

Voltage:

Ignition system:Ignition timing (B.T.D.C.)

12V

16.5°/3,000 r/rnin

BR250Trrs

ucir:e:i 20 I—j—t-+—+—l—+—+-+—l-~

-/~

8 10 h~f—t—+—+-+—l—+-+—+—If—1′;:;’2E

o 246 8

Engine speed (x 103 r/mln)

10

C.D.I.:Magneto model/ManufacturerPickup coil resistance(color code)Source coil resistance(color code)Lighting voltage-(minimum)Lighting voltage-(maximum)Lighting coil resistance(color code)Coil resistance for grip warmer(color code)C.D.1. unit manufacturer

Ignition coil:Model/ManufacturerMinimum spark gapPrimary coil resistanceSecondary coil resistance

Spark plug cap:TypeResistance

Charging system:Type

F85LIYAMAHA20 Q ± 20% at 20°C (68°F)(Wh ite/Hed — Black)275 Q ± 20% at 20°C (68°F)(Brown — Black)11 V/3,000 r/rnln15 V/6,000 r/min0.3 Q ± 20% at 20°C (68°F)(Yellow — Black)0.8 Q ± 20% at 20°C (68°F)(Red — Black)8AU-00/YAMAHA

86B-00IYAMAHA3 mm (0.12 in)0.4 Q ± 20% at 20°C (68°F)7.1 kQ ± 20% at 20°C (68°F)

Resin type5 kQ at 20°C (68°F)

Flywheel magneto

-27-

GENERAL TORQUE SPECIFICATIONS ISPECI g—I9E051

GENERAL TORQUESPECIFICATIONSThis chart specifies torque for standard fastenerswith standard I.S.0. pitch threads. Torque specifi­

cations for special components or assemblies areincluded inthe applicable sections ofthis book. Toavoid warpage, tighten multi-fastenerassemblies

in acrisscross fashion, in progressive stages, until

full torque is reached. Unless otherwise specified,torque specifications call for clean, dry threads.

Components should be at room temperature.

IA

L~

A: Distance across flatsB: Outside thread diameter

-28-

A B General Torque

(nut) (bolt) Specifications

Nm rn-kq ft-lb

10mm 6mm 6 0.6 4.3

12 mm 8mm 15 1.5 11

14mm 10mm 30 3.0 22

17 mm 12 mm 55 5.5 40

19mm 14mm 85 8.5 61

22mm 16mm 130 13.0 94

CABLE ROUTING ISPECI a-ICABLE ROUTING

® Band

@) Starter cable

® Speedometercable

® Brake cable

® Clamp

® Clamp the wireharnessand pulser hose.

® Wireharness

@ Earth

@ Grommet

@ To headlight

\

® Clamp

CD Throttle cable

® Clamp__—-.::.._—e:t’

® Band (80)…I..-_~

c

120@ Clamp the

wireharness

@Clip

® Wireharness

@ Shroud

® Clamp the breatherhose.

® Brake cable

@ Breather hose

/

@ Clamp the wireharness

D

@ Primer pump hose

C (with primer pump*)* Option

(J) Headlight lead

C (without primer pump)

® Wireharness

@ Breatherhose

® Brake cable

8

-29-

CABLE ROUTING ISPECI 0—1

® Clamp

E

® To oil pump@ Clamp the fuel hose, oil hose,

pulser hose and wireharness.

@ Breather hose

® Fuel level hose

@ Band

~~_ @ To carburetor switch

/ @ To fuel pump

® Oil hose

! ® Clamp

@ To flywheel magneto

/® To crankcase

@) To ignition coil

t!»»‘-.

® Oil hose

~ ® To carburetor

E

CD Voltage regulator

® Grommet

® Wireharness

(J) Fuel suction hose

® Fuel level hose

@ Breather hose

@ To C.D.1. unit

® To meter ‘i’assembly -c_,,» »» …. «»

® Fuel hose

®> From primer pump(gold color nozzle)

@ Joint !

(J) Fuel suction hose

® Primer pump hose® Pulser hose

A (with primer pump*)* Option A (without primer pump)

-30-

CABLE ROUTING ISPECI 0-1

CD Fuel level hose

® Sub tank

® Fuel suction hose

@ To taillight—

® Oil hose

® Breather hose

(j) Pass the wireharness belowthe fuel tank.

@ Starter cable

® Fuel pump

® From recovery tank@ Throttle cable

@ Brake cable

@ Oil pump

® Oil hose

® Breather hose

® Pulser hose

® Fuel suction hose

® Indicator panel

@ Oil tank

@ Place the taillight leadcoupler as shown.

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CABLE ROUTING 1SPECI0—1

@ Speedometer lead

® Speedometer cable

® Starter cable

® Clamp

@ Taillight lead

BR250T

® Clamp

(J) Band

® Recovery tank

® Headlight beam switch

® Tail/Brake light lead

@ Main switch

® Voltage regulator

® Grip warmer

@ Grip warmer switch

@ JlENGINE STOP» switch

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1. Manuals
2. Brands
3. Yamaha Manuals
4. Offroad Vehicle
5. BR250F
6. Service manual

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• Troubleshooting

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Summary of Contents for Yamaha BR250F