Page 226 of 762

3 - 1
INSP
ADJ
MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-inEvery
race
Every
third
or
500 km
(300 mi)Every
fifth
or
1,000 km
(600 mi)
As re-
quiredRemarks
ENGINE OIL
Replace
cc
OIL FILTER
Clean
cc
VALVES
Check the valve clearances.
Inspect
Replace
cc
c
c
The engine must be cold.
Check the valve seats and
valve stems for wear.
VALVE SPRINGS
Inspect
Replace
c
c
Check the free length and
the tilt.
VALVE LIFTERS
Inspect
Replace
c
c
Check for scratches and
wear.
CAMSHAFTS
Inspect
Replace
c
c
Inspect the camshaft sur-
face.
CAMSHAFT SPROCKETS
Inspect
Replace
c
c
Check for wear on the
teeth and for damage.
PISTON
Inspect
Clean
Replace
cc
c
c
Inspect crack
Remove carbon
PISTON RING
Inspect
Replace
c
cc
Check ring end gap
PISTON PIN
Inspect
Replace
c
c
CYLINDER HEAD
Inspect and clean
c
Remove carbon
Change gasket
CYLINDER
Inspect and clean
Replace
c
c
Inspect score marks
Inspect wear
CLUTCH
Inspect and adjust
Replace
cc
c
Inspect housing, friction
plate, clutch plate and
spring
TRANSMISSION
Inspect
Replace bearing
c
c
3
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4 - 64
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
REMOVAL POINTS
EC4G3110
Impeller shaft
1. Remove:
lImpeller 1
lPlain washer 2
lImpeller shaft 3
NOTE:
Hold the impeller shaft on its width across the
flats a with spanners, etc. and remove the
impeller.
EC4G3210
Oil seal
NOTE:
It is not necessary to disassemble the water
pump, unless there is an abnormality such as
excessive change in coolant level, discolora-
tion of coolant, or milky transmission oil.
1. Remove:
lBearing 1
lOil seal 2
INSPECTION
EC444200
Impeller shaft
1. Inspect:
lImpeller shaft 1
Bend/wear/damage ® Replace.
Fur deposits ® Clean.
Page 522 of 762
ENG
4 - 94 CRANKCASE BEARING
Extent of removal:1 Crankcase bearing removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE BEARING
REMOVAL
Preparation for removal Transmission
Shift cam and shift forkRefer to “TRANSMISSION, SHIFT
CAM AND SHIFT FORK” section.
1 Oil seal 3
2 Bearing 10 Refer to “REMOVAL POINTS”.
1
CRANKCASE AND CRANKSHAFT
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4 - 99
ENGCRANKCASE AND CRANKSHAFT
2. Check:
lShifter operation
lTransmission operation
Unsmooth operation ® Repair.
3. Install:
lOil strainer 1
lBolt (oil strainer) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
4. Apply:
lSealant
On the crankcase (right) 1.
NOTE:
Clean the contacting surface of crankcase (left
and right) before applying the sealant.
5. Install:
lDowel pin 1
lO-ring 2
lCrankcase (right)
To crankcase (left).
NOTE:
lFit the crankcase (right) onto the crankcase
(left). Tap lightly on the case with soft ham-
mer.
lWhen installing the crankcase, the connect-
ing rod should be positioned at TDC (top
dead center).
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No. 1215:
90890-85505
New
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4 - 100
ENGCRANKCASE AND CRANKSHAFT
6. Tighten:
lHose guide 1
lClutch cable holder 2
lBolt (crankcase)
NOTE:
Tighten the crankcase tightening bolts in
stage, using a crisscross pattern.
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
7. Install:
lOil delivery pipe
lO-ring
lBolt (oil delivery pipe)
8. Install:
lTiming chain
lTiming chain guide (rear)
lBolt (timing chain guide)
9. Remove:
lSealant
Forced out on the cylinder mating sur-
face.
10. Apply:
lEngine oil
To the crank pin, bearing and oil deliv-
ery hole.
11. Check:
lCrankshaft and transmission operation.
Unsmooth operation ® Repair.
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
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4 - 103
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H4801
Shift fork, shift cam and segment
1. Inspect:
lShift fork 1
Wear/damage/scratches ® Replace.
2. Inspect:
lShift cam 1
lSegment 2
Bend/wear/damage ® Replace.
3. Check:
lShift fork movement
Unsmooth operation ® Replace shift
fork.
NOTE:
For a malfunctioning shift fork, replace not only
the shift fork itself but the two gears each adja-
cent to the shift fork.
ASSEMBLY AND INSTALLATION
Transmission
1. Install:
l5th pinion gear (25T) 1
l3rd pinion gear (16T) 2
lCollar 3
l4th pinion gear (20T) 4
l2nd pinion gear (15T) 5
To main axle 6.
NOTE:
lApply the molybdenum disulfide oil on the
4th and 5th pinion gears inner circumference
and on the end surface.
lApply the molybdenum disulfide oil on the
2nd and 3rd pinion gears inner circumfer-
ence.
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ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
2. Install:
l2nd wheel gear (26T) 1
l4th wheel gear (21T) 2
l3rd wheel gear (21T) 3
l5th wheel gear (21T) 4
l1st wheel gear (29T) 5
lO-ring 6
To drive axle 7.
NOTE:
lApply the molybdenum disulfide oil on the
1st, 2nd and 3rd wheel gears inner circum-
ference and on the end surface.
lApply the molybdenum disulfide oil on the
4th and 5th wheel gears inner circumfer-
ence.
lApply the lithium soap base grease on the O-
ring.
3. Install:
lPlain washer 1
lCirclip 2
NOTE:
lBe sure the circlip sharp-edged corner a is
positioned opposite side to the plain washer
and gear b.
lBe sure the circlip end c is positioned at
axle spline groove d.
New
4. Install:
lCollar 1
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lWhen installing the spacer into the crank-
case, pay careful attention to the crankcase
oil seal lip.
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4 - 105
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
5. Install:
lShift fork 1 (L) 1
lShift fork 2 (C) 2
lShift fork 3 (R) 3
lShift cam 4
To main axle and drive axle.
NOTE:
lApply the molybdenum disulfide oil on the
shift fork grooves.
lMesh the shift fork #1 (L) with the 4th wheel
gear 5 and #3 (R) with the 5th wheel gear
7 on the drive axle.
lMesh the shift fork #2 (C) with the 3rd pinion
gear 6 on the main axle.
6. Install:
lTransmission assembly 1
To crankcase (left) 2.
NOTE:
Apply the engine oil on the bearings and guide
bars.
7. Check:
lShifter operation
lTransmission operation
Unsmooth operation ® Repair.