2006 YAMAHA YZ250LC oil

Extent of removal Order Part name Q’ty Remarks
FRONT FORK DISASSEMBLY
1Adjuster 1 Drain the fork oil. Use special tool.
Refer to “REMOVAL POINTS”.
2Fork spring 1
3Dust seal 1
4Stopper ring 1 Refer to “REMOVAL POINTS”.
5Inner tube 1
6Outer tube 1
7Piston metal 1
8Slide metal 1
9Oil seal washer 1
0Oil seal 1
qBase valve 1 Drain the fork oil. Use special tool.
wDamper assembly 1 Refer to “REMOVAL POINTS”.
5-27
CHASFRONT FORK
EC558000
FRONT FORK DISASSEMBLY
1
Extent of removal:1Oil seal removal2Damper assembly removal
2






29 Nm (2.9 m•kg, 21 ft•lb)
1 Nm (0.1 m•kg, 0.7 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
55 Nm (5.5 m•kg, 40 ft•lb)29 Nm (2.9 m•kg, 21 ft•lb)
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5-28
CHASFRONT FORK
EC556000
HANDLING NOTE
NOTE:
The front fork requires careful attention. So it is
recommended that the front fork be maintained
at the dealers.
cC
To prevent an accidental explosion of air,
the following instructions should be ob-
served:
9The 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 re-
placed or when the front fork is disassem-
bled and reassembled.
9Before removing the base valves or front
forks, be sure to extract the air from the air
chamber completely.
EC553000
REMOVAL POINTS
EC553311
Damper assembly
1. Loosen:
9Damper assembly 1
NOTE:
Before removing the front fork from the
machine, loosen the damper assembly with
the cap bolt ring wrench 2.
Cap bolt ring wrench:
YM-01501/90890-01501
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5-29
CHASFRONT FORK
Adjuster
1. Drain the outer tube of its front fork oil at its
top.
2. Loosen:
9Adjuster 1
3. Remove:
9Adjuster 1
NOTE:
9While compressing the inner tube 2, set the
cap bolt ring wrench 4between the inner tube
and locknut 3.
9Hold the locknut and remove the adjuster.
cC
Do not remove the locknut as the damper
rod may go into the damper assembly and
not be taken out.
Cap bolt ring wrench:
YM-01501/90890-01501
EC553201
Inner tube
1. Remove:
9Dust seal 1
9Stopper ring 2
Using slotted-head screwdriver.
cC
Take care not to scratch the inner tube.
2. Remove:
9Inner tube 1
Oil seal removal steps:
9Push in slowly athe inner tube just be-
fore it bottoms out and then pull it back
quickly b.
9Repeat this step until the inner tube can
be pulled out from the outer tube.
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5-30
CHASFRONT FORK
Base valve
1. Remove:
9Base valve 1
From damper assembly 2.
NOTE:
Hold the damper assembly with the cap bolt ring
wrench 3and use the cap bolt wrench 4to
remove the base valve.
EC554000
INSPECTIONEC554100
Damper assembly
1. Inspect:
9Damper assembly 1
Bend/DamageReplace.
9O-ring 2
Wear/DamageReplace.
cC
The front fork with a built-in piston rod has
a very sophisticated internal construction
and is particularly sensitive to foreign ma-
terial.
Use enough care not to allow any foreign
material to come in when the oil is re-
placed or when the front fork is disassem-
bled and reassembled.
Cap bolt wrench:
YM-01500/90890-01500
Cap bolt ring wrench:
YM-01501/90890-01501
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5-32
CHASFRONT FORK
EC554502
Inner tube
1. Inspect:
9Inner tube surface a
Score marksRepair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock pieceReplace.
9Inner tube bends
Out of specificationReplace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
w
Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
Inner tube bending limit:
0.2 mm (0.008 in)
EC554600
Outer tube
1. Inspect:
9Outer tube 1
Score marks/Wear/DamageReplace.
Adjuster
1. Inspect:
9Adjuster 1
9O-ring 2
Wear/DamageReplace.
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5-33
CHASFRONT FORK
EC555000
ASSEMBLY AND INSTALLATIONEC5551D0
Front fork assembly
1. Wash the all parts in a clean solvent.
2. Stretch the damper assembly fully.
3. Fill:
9Front fork oil 1
To damper assembly.
cC
9Be sure to use recommended fork oil. If
other oils are used, they may have an ex-
cessively adverse effect on the front fork
performance.
9Never allow foreign materials to enter the
front fork.
Recommended oil:
Suspension oil “S1”
Oil capacity:
195cm
3(6.86 Imp oz, 6.59 US oz)
4. After filling, pump the damper assembly 1
slowly up and down (about 200 mm (7.9 in)
stroke) several times to bleed the damper
assembly of air.
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 2 to
4.
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5-34
CHASFRONT FORK
5. Measure:
9Oil level (left and right) a
Out of specification  Adjust.
Standard oil level:
145~148 mm (5.71~5.83 in)
From top of fully stretched
damper assembly.
6. Tighten:
9Locknut 1
NOTE:
Fully finger tighten the locknut onto the
damper assembly.
7. Loosen:
9Compression damping adjuster 1
NOTE:
9Loosen the compression damping adjuster fin-
ger tight.
9Record the set position of the adjuster (the
amount of turning out the fully turned in posi-
tion).
8. Install:
9Base valve 1
To damper assembly 2.
NOTE:
First bring the damper rod pressure to a maxi-
mum. Then install the base valve while releas-
ing the damper rod pressure.
9. Check that the damper assembly is fully
stretched.
Not fully stretched  Repeat the steps 2 to 8.
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10. Tighten:
9Base valve 1
NOTE:
Hold the damper assembly with the cap bolt
ring wrench
2and use the cap bolt wrench 3
to tighten the base valve with specified torque.
11. After filling, pump the damper assembly 1
slowly up and down more than 10 times to
distribute the fork oil.
5-35
CHASFRONT FORK
12. While protecting the damper assembly 1
with a rag and compressing fully, allow
excessive oil to overflow on the base valve
side.
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Take care not to damage the damper
assembly.
13. Allow the overflowing oil to escape at the
hole ain the damper assembly.
14. Check:
9Damper assembly smooth movement
Tightness/Binding/Rough spots  Repeat
the steps 2 to 13.
29 Nm (2.9 m•kg, 21 ft•lb)
Cap bolt wrench:
YM-01500/90890-01500
Cap bolt ring wrench:
YM-01501/90890-01501
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