2004 YAMAHA YZ250F fork

3 - 42
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
2. Inspect:
Bearing free play
Exist play → Replace.
EC36U013
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suit-
able stand under the engine.
2. Check:
Steering stem
Grasp the bottom of the forks and gen-
tly rock the fork assembly back and
forth.
Free play → Adjust steering head.
3. Check:
Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action → Adjust steering ring
nut.
4. Adjust:
Steering ring nut
Steering ring nut adjustment steps:
Remove the number plate.
Remove the handlebar and handlebar
upper bracket.
Loosen the steering ring nut 1 using the
steering nut wrench 2.
Steering nut wrench:
YU-33975/90890-01403

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ENGCRANKCASE AND CRANKSHAFT
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 2
2 Bearing 10 Refer to “REMOVAL POINTS”.
1

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ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H0000
TRANSMISSION, SHIFT CAM AND SHIFT FORK
Extent of removal:1 Shift fork, shift cam, main axle and drive axle removal
Extent of removal Order Part name Q’ty Remarks
TRANSMISSION, SHIFT CAM
AND SHIFT FORK REMOVAL
Preparation for removal Engine Refer to “ENGINE REMOVAL” section.
Separate the crankcase. Refer to “CRANKCASE AND CRANK-
SHAFT” section.
1 Main axle 1
Refer to “REMOVAL POINTS”. 2 Drive axle 1
3 Shift cam 1
4 Shift fork 3 1
5 Shift fork 2 1
6 Shift fork 1 1
7 Collar 1
1

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ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H3000
REMOVAL POINTS
EC4H3230
Transmission
1. Remove:
Main axle 1
Drive axle 2
Shift cam
Shift fork 3
Shift fork 2
Shift fork 1
NOTE:
Remove assembly with the collar 3 installed
to the crankcase.
Remove assembly carefully. Note the posi-
tion of each part. Pay particular attention to
the location and direction of shift forks.
Remove the main axle, drive axle, shift cam
and shift fork all together by tapping lightly
on the transmission drive axle with a soft
hammer.
EC4H4000
INSPECTION
EC4H4200
Gears
1. Inspect:
Matching dog a
Gear teeth b
Shift fork groove c
Wear/damage → Replace.
2. Inspect:
O-ring 1
Damage → Replace.
3. Check:
Gears movement
Unsmooth movement → Repair or
replace.
EC4H4600
Bearing
1. Inspect:
Bearing 1
Rotate inner race with a finger.
Rough spot/seizure → Replace.

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ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H4810
Shift fork, shift cam and segment
1. Inspect:
Shift fork 1
Wear/damage/scratches → Replace.
2. Inspect:
Shift cam 1
Segment 2
Wear/damage → Replace.
3. Check:
Shift 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:
5th pinion gear (24T) 1
3rd pinion gear (20T) 2
Collar 3
4th pinion gear (22T) 4
2nd pinion gear (16T) 5
To main axle 6.
NOTE:
Apply the molybdenum disulfide oil on the
4th and 5th pinion gears inner circumference
and on the end surface.
Apply 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:
2nd wheel gear (28T) 1
4th wheel gear (27T) 2
3rd wheel gear (29T) 3
5th wheel gear (25T) 4
1st wheel gear (30T) 5
O-ring 6
To drive axle 7.
NOTE:
Apply the molybdenum disulfide oil on the
1st, 2nd and 3rd wheel gears inner circum-
ference and on the end surface.
Apply the molybdenum disulfide oil on the
4th and 5th wheel gears inner circumfer-
ence.
Apply the lithium soap base grease on the O-
ring.
3. Install:
Washer 1
Circlip 2
NOTE:
Be sure the circlip sharp-edged corner a is
positioned opposite side to the washer and
gear b.
Install the circlip with its ends c settled
evenly on the spline crests.
cc
4. Install:
Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
When installing the collar into the crankcase,
pay careful attention to the crankcase oil seal
lip.

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ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
5. Install:
Shift fork 1 (L) 1
Shift fork 2 (C) 2
Shift fork 3 (R) 3
Shift cam 4
To main axle and drive axle.
NOTE:
Apply the molybdenum disulfide oil on the
shift fork grooves.
Mesh the shift fork #1 (L) with the 4th wheel
gear 5 and #3 (R) with the 5th wheel gear
7 on the drive axle.
Mesh the shift fork #2 (C) with the 3rd pinion
gear 6 on the main axle.
6. Install:
Transmission assembly 1
To left crankcase 2.
NOTE:
Apply the engine oil on the bearings and guide
bars.
7. Check:
Shifter operation
Transmission operation
Unsmooth operation → Repair.

5 - 6
CHASFRONT WHEEL AND REAR WHEEL
5. Install:
Wheel axle 1
NOTE:
Apply the lithium soap base grease on the
wheel axle.
6. Install:
Nut (wheel axle) 1
T R..105 Nm (10.5 m · kg, 75 ft · lb)
7. Tighten:
Bolt (axle holder) 1
NOTE:
Before tightening the bolt, fit the wheel axle to
the axle holder by stroking the front fork sev-
eral times with the front brake applied.
8. Install:
Brake hose 1
To brake hose holder 2.
NOTE:
Before tightening the bolt (brake hose holder),
align the top a of the brake hose neck with the
brake hose holder bottom b. Then pass the
brake hose in front of the axle boss c and fit it
into the hose groove d so that the brake hose
does not contact the nut (wheel axle).
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)