2001 YAMAHA YZ250F oil

5 - 31
CHAS
EC554200
Base valve
1. Inspect:
lValve assembly 1
Wear/damage ® Replace.
lO-ring 2
Damage ® Replace.
EC554400
Fork spring
1. Measure:
lFork spring free length a
Out of specification ® Replace.
EC554502
Inner tube
1. Inspect:
lInner tube surface a
Score marks ® Repair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock piece ® Replace.
lInner tube bends
Out of specification ® Replace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
EC554600
Outer tube
1. Inspect:
lOuter tube 1
Score marks/wear/damage ® Replace.
Fork spring free length:
460 mm (18.1 in)
: 455 mm (17.9 in)
Inner tube bending limit:
0.2 mm (0.008 in)
FRONT FORK

5 - 33
CHASFRONT FORK
5. Install:
lSpring guide 1
lLocknut 2
To damper rod 3.
NOTE:
lInstall the spring guide with its cut a facing
upward.
lWith its thread b facing upward, fully finger
tighten the locknut onto the damper rod.
6. Install:
lDust seal 1
lStopper ring 2
lOil seal 3
lOil seal washer 4
lSlide metal 5
To inner tube 6.
NOTE:
lApply the fork oil on the inner tube.
lWhen installing the oil seal, use vinyl seat a
with fork oil applied to protect the oil seal lip.
lInstall the oil seal with its manufacture’s
marks or number facing the axle holder side.
7. Install:
lPiston metal 1
NOTE:
Install the piston metal onto the slot on inner
tube.
8. Install:
lOuter tube 1
To inner tube 2.

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CHASFRONT FORK
9. Install:
lSlide metal 1
lOil seal washer 2
To outer tube slot.
NOTE:
Press the slide metal into the outer tube with
fork seal driver 3.
Fork seal driver:
YM-01442/90890-01442
10. Install:
lOil seal 1
NOTE:
Press the oil seal into the outer tube with fork
seal driver 2.
Fork seal driver:
YM-01442/90890-01442
11. Install:
lStopper ring 1
NOTE:
Fit the stopper ring correctly in the groove in
the outer tube.
12. Install:
lDust seal 1
NOTE:
Apply the lithium soap base grease on the
inner tube.

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CHASFRONT FORK
13. Check:
lInner tube smooth movement
Tightness/binding/rough spots ®
Repeat the steps 2 to 12.
14. Compress the front fork fully.
15. Fill:
lFront fork oil
Until outer tube top surface with recom-
mended fork oil 1.
ACHTUNG:CAUTION:
lBe sure to use recommended fork oil. If
other oils are used, they may have an
excessively adverse effect on the front
fork performance.
lNever allow foreign materials to enter the
front fork.
Recommended oil:
Suspension oil “01”
16. After filling, pump the damper rod 1
slowly up and down more than 10 times
to distribute the fork oil.
17. Fill:
lFront fork oil
Until outer tube top surface with recom-
mended fork oil once more.
18. After filling, pump the outer tube 1 slowly
up and down (about 200 mm (7.9 in)
stroke) to distribute the fork oil once
more.
NOTE:
Be careful not to excessive full stroke. A stroke
of 200 mm (7.9 in) or more will cause air to
enter. In this case, repeat the steps 15 to 18.

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CHASFRONT FORK
19. Wait ten minutes until the air bubbles
have been removed from the front fork,
and the oil has dispense evenly in system
before setting recommended oil level.
NOTE:
Fill with the fork oil up to the top end of the
outer tube, or the fork oil will not spread over to
every part of the front forks, thus making it
impossible to obtain the correct level.
Be sure to fill with the fork oil up to the top of
the outer tube and bleed the front forks.
20. Measure:
lOil level (left and right) a
Out of specification ® Adjust.
NOTE:
Be sure to install the spring guide 2 when
checking the oil level.
WARNING
Never fail to make the oil level adjustment
between the maximum and minimum level
and always adjust each front fork to the
same setting. Uneven adjustment can
cause poor handling and loss of stability.
Standard oil level:
140 mm (5.51 in)
Extent of adjustment:
80 ~ 150 mm (3.15 ~ 5.91 in)
From top of outer tube with
inner tube and damper rod 1
fully compressed without
spring.

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CHASHANDLEBAR
EC5B5000
ASSEMBLY AND INSTALLATION
Handlebar
1. Install:
lHandlebar 1
lHandlebar upper holder 2
lBolt (handlebar upper holder) 3
NOTE:
lThe handlebar upper holder should be
installed with the punched mark a forward.
lFirst tighten the bolts on the front side of the
handlebar upper holder, and then tighten the
bolts on the rear side.
2. Install:
lLeft grip 1
Apply the adhesive to the handlebar 2.
NOTE:
lBefore applying the adhesive, wipe off
grease or oil on the handlebar surface a
with a lacquer thinner.
lInstall the left grip to the handlebar so that
the line b between the two arrow marks
faces straight upward.
T R..28 Nm (2.8 m · kg, 20 ft · lb)
3. Install:
lRight grip 1
lCollar 2
Apply the adhesive on the tube guide
3.
NOTE:
lBefore applying the adhesive, wipe off
grease or oil on the tube guide surface a
with a lacquer thinner.
lInstall the grip to the tube guide so that the
grip match mark b and tube guide slot c
form the angle as shown.
R
L
90˚
2 1b
c

5 - 51
CHASSWINGARM
EC578000
SWINGARM DISASSEMBLY
Extent of removal:1 Swingarm disassembly2 Connecting rod removal and disassembly
3 Relay arm removal and disassembly
Extent of removal Order Part name Q’ty Remarks
SWINGARM DISASSEMBLY
1 Cap 2
2 Relay arm 1
3 Connecting rod 1
4 Collar 2
5 Oil seal 2
6 Thrust bearing 2
7 Bushing 2
8 Oil seal 8
9 Bearing 8 Refer to “REMOVAL POINTS”.
1
2
32
3

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CHASSWINGARM
EC573000
REMOVAL POINTS
EC573200
Bearing
1. Remove:
lBearing 1
NOTE:
Install the bearing by pressing its outer race.
INSPECTION
Wash the bearings, bushings, collars, and cov-
ers in a solvent.
Swingarm
1. Inspect:
lBearing 1
lBushing 2
Free play exists/unsmooth revolution/
rust ® Replace bearing and bushing as
a set.
2. Inspect:
lOil seal 3
Damage ® Replace.
EC574210
Relay arm
1. Inspect:
lBearing 1
lCollar 2
Free play exists/unsmooth revolution/rust
® Replace bearing and collar as a set.
2. Inspect:
lOil seal 3
Damage ® Replace.
EC574310
Connecting rod
1. Inspect:
lBearing 1
lCollar 2
Free play exists/unsmooth revolution/rust
® Replace bearing and collar as a set.
2. Inspect:
lOil seal 3
Damage ® Replace.