oil YAMAHA YZ250F 2001 Notices Demploi (in French)

5 - 25
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
lBrake hose holder 1
lScrew (brake hose holder) 2
ACHTUNG:CAUTION:
After installing the brake hose holders,
make sure the brake hose does not contact
the spring (rear shock absorber). If it does,
correct its twist.
Brake fluid
1. Fill:
lBrake fluid
Until the fluid level reaches “LOWER”
level line a.
WARNING
lUse only the designated quality brake
fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
lRefill with the same type of brake fluid;
mixing fluids may result in a harmful chem-
ical reaction and lead to poor performance.
lBe careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
fluid and may result in vapor lock.
ACHTUNG:CAUTION:
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
Front
õRear
Recommended brake fluid:
DOT #4
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)

õ

5 - 28
CHASFRONT FORK
EC558000
FRONT FORK DISASSEMBLY
Extent of removal:1 Oil seal removal2 Damper rod removal
Extent of removal Order Part name Q’ty Remarks
FRONT FORK DISASSEMBLY
1 Front fork cap bolt 1 Refer to “REMOVAL POINTS”.
2 Fork spring 1 Drain the fork oil.
3 Dust seal 1
Refer to “REMOVAL POINTS”. 4 Stopper ring 1
5 Inner tube 1
6 Outer tube 1
7 Piston metal 1
8 Slide metal 1
9 Oil seal washer 1
0 Oil seal 1
A Spring guide 1
B Base valve 1 Use special tool.
C Damper rod 1 Refer to “REMOVAL POINTS”.
1
2

5 - 29
CHASFRONT FORK
EC556000
HANDLING NOTE
NOTE:
The front fork requires careful attention. So it is
recommended that the front fork be main-
tained at the dealers.
ACHTUNG:CAUTION:
To prevent an accidental explosion of air,
the following instructions should be
observed:
lThe front fork with a built-in piston rod
has a very sophisticated internal con-
struction and is particularly sensitive to
foreign material.
Use enough care not to allow any foreign
material to come in when the oil is
replaced or when the front fork is disas-
sembled and reassembled.
lBefore removing the cap bolts or front
forks, be sure to extract the air from the
air chamber completely.
EC553000
REMOVAL POINTS
Front fork cap bolt
1. Remove:
lFront fork cap bolt 1
From the outer tube.
NOTE:
Before removing the front fork from the
machine, loosen the front fork cap bolt.
2. Remove:
lFront fork cap bolt 1
NOTE:
lWhile compressing the fork spring, set the
thin type spanners 2 between the spacer 3
and spring guide 4.
lHold the locknut 5 and remove the front fork
cap bolt.

5 - 30
CHAS
EC553201
Inner tube
1. Remove:
lDust seal 1
lStopper ring 2
Using slotted-head screwdriver.
ACHTUNG:CAUTION:
Take care not to scratch the inner tube.
2. Remove:
lInner tube 1
Oil seal removal steps:
lPush in slowly a the inner tube just before
it bottoms out and then pull it back quickly
b.
lRepeat this step until the inner tube can
be pulled out from the outer tube.
EC553311
Damper rod
1. Remove:
lBase valve 1
lDamper rod 2
NOTE:
Use a damper rod holder 3 to lock the damper
rod.
EC554000
INSPECTION
EC554100
Damper rod
1. Inspect:
lDamper rod 1
Bend/damage ® Replace damper rod.
ACHTUNG:CAUTION:
The front fork with a built-in piston rod has
a very sophisticated internal construction
and is particularly sensitive to foreign
material.
Use enough care not to allow any foreign
material to come in when the oil is replaced
or when the front fork is disassembled and
reassembled.
Damper rod holder:
YM-1423/90890-01423
FRONT FORK

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.

5 - 34
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.

5 - 35
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.

5 - 36
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.

5 - 42
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