Yamaha YZ450F(X), Owner'S Service Manual

Page: 61 / 574

3-17
CHASSIS
CHECKING THE FRONT FORK
1. Inspect:
• Front fork smooth action
Operate the front brake and
stroke the front fork.
Unsmooth action/oil leakage
→
Repair or replace.
CLEANING THE FRONT FORK OIL
SEAL AND DUST SEAL
1. Remove:
• Protector
• Dust seal "1"
Use a thin screw driver, and be care-
ful not to damage the inner fork tube
and dust seal.
2. Clean:
• Dust seal "a"
• Oil seal "b"
• Clean the dust seal and oil seal af-
ter every run.
• Apply the lithium soap base grease
on the inner tube.
RELIEVING THE FRONT FORK
INTERNAL PRESSURE
If the front fork initial movement feels
stiff during a run, relieve the front fork
internal pressure.
1. Elevate the front wheel by placing
a suitable stand under the engine.
2. Remove the air bleed screw "1"
and release the internal pressure
from the front fork.
3. Install:
• Air bleed screw
ADJUSTING THE FRONT FORK
REBOUND DAMPING FORCE
1. Adjust:
• Rebound damping force
By turning the adjuster "1".
• STANDARD POSITION:
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
Always adjust each front fork to
the same setting. Uneven adjust-
ment can cause poor handling and
loss of stability.
ADJUSTING THE FRONT FORK
COMPRESSION DAMPING FORCE
1. Adjust:
• Compression damping force
By turning the adjuster "1".
• STANDARD POSITION:
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
Always adjust each front fork to
the same setting. Uneven adjust-
ment can cause poor handling and
loss of stability.
CHECKING THE REAR SHOCK
ABSORBER
1. Inspect:
• Swingarm smooth action
Abnormal noise/unsmooth action
→
Grease the pivoting points or
repair the pivoting points.
Damage/oil leakage
→
Replace.
Air bleed screw:
1 Nm (0.1 m•kg, 0.7
ft•lb)
Stiffer "a"
→
Increase the re-
bound damping force. (Turn
the adjuster "1" in.)
Softer "b"
→
Decrease the re-
bound damping force. (Turn
the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position
20 clicks out
(from maximum
position)
Standard position:
12 clicks out
* 11 clicks out
* For EUROPE
Stiffer "a"
→
Increase the com-
pression damping force. (Turn
the adjuster "1" in.)
Softer "b"
→
Decrease the com-
pression damping force. (Turn
the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position
20 clicks out
(from maximum
position)
Standard position:
12 clicks out
* 7 clicks out
* For EUROPE