2001 YAMAHA WR 250F oil

4 - 94
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 right crankcase 1.
NOTE:
Clean the contacting surface of left and right
crankcase before applying the sealant.
5. Install:
lDowel pin 1
lO-ring 2
lRight crankcase
To left crankcase.
NOTE:
lFit the right crankcase onto the left crank-
case. 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

4 - 95
ENGCRANKCASE AND CRANKSHAFT
6. Tighten:
lHose guide 1
lClutch cable holder 2
lBolt (crankcase) 3
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 2 1
lO-ring 2
lBolt (oil delivery pipe 2) 3
NOTE:
Apply the lithium soap base grease on the O-
rings.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
8. Install:
lTiming chain 1
lTiming chain guide (intake side) 2
lBolt (timing chain guide) 3
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.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 98
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H4810
Shift fork, shift cam and segment
1. Inspect:
lShift fork 1
Wear/damage/scratches ® Replace.
2. Inspect:
lShift cam 1
lSegment 2
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.
EC4H5000
ASSEMBLY AND INSTALLATION
Transmission
1. Install:
l5th pinion gear (27T) 1
l3rd pinion gear (21T) 2
lCollar 3
l4th pinion gear (24T) 4
l2nd pinion gear (16T) 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.

4 - 99
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
2. Install:
l2nd wheel gear (28T) 1
l4th wheel gear (25T) 2
l3rd wheel gear (28T) 3
l5th wheel gear (22T) 4
l1st wheel gear (31T) 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:
lWasher 1
lCirclip 2
NOTE:
lBe sure the circlip sharp-edged corner a is
positioned opposite side to the washer and
gear b.
lBe sure the circlip end c is positioned at
axle spline groove d.
4. Install:
lCollar 1
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lWhen installing the collar into the crankcase,
pay careful attention to the crankcase oil seal
lip.

4 - 100
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 left crankcase 2.
NOTE:
Apply the engine oil on the bearings and guide
bars.
7. Check:
lShifter operation
lTransmission operation
Unsmooth operation ® Repair.

5 - 1
CHAS

EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1
Front wheel removal
2
Wheel bearing removal
3
Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
FRONT WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
1 Trip meter cable 1
2 Brake hose cover 1
3 Bolt (brake hose holder) 2 Only loosening.
4 Bolt (axle holder) 4 Only loosening.
5 Nut (front wheel axle) 1
6 Front wheel axle 1
7 Front wheel 1
8 Trip meter gear unit 1
9 Collar 1
10 Oil seal 1
11 Bearing 2 Refer to “REMOVAL POINTS”.
12 Brake disc 1
2
31
3





5

5 - 2
CHAS

EC598100
REAR WHEEL
Extent of removal:
1
Rear wheel removal
2
Wheel bearing removal
3
Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
REAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Drive chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Rear wheel sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disc
1
2
31
3

FRONT WHEEL AND REAR WHEEL

5 - 3
CHAS

FRONT WHEEL AND REAR WHEEL
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:
l
Wheel
1

NOTE:

Push the wheel forward and remove the drive
chain
2
.
EC513201
Wheel bearing (if necessary)
1. Remove:
l
Bearing
1

NOTE:

Remove the bearing using a general bearing
puller
2
.
EC594000
INSPECTION
EC514100
Wheel
1. Measure:
l
Wheel runout
Out of limit
®
Repair/replace.
2. Inspect:
l
Bearing
Rotate inner race with a finger.
Rough spot/seizure
®
Replace.
NOTE:

Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial
1
: 2.0 mm (0.08 in)
Lateral
2
: 2.0 mm (0.08 in)