Yamaha YZ450F(X) Owner's Service Manual page 63

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
Air bleed screw:
1 Nm (0.1 m•kg, 0.7
ft•lb)
→
ADJUSTING THE FRONT FORK
REBOUND DAMPING FORCE
1. Adjust:
• Rebound damping force
By turning the adjuster "1".
→
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
Fully turned in
position
• STANDARD POSITION:
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
Standard position:
12 clicks out
* 11 clicks out
* For EUROPE
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.
3-17
ADJUSTING THE FRONT FORK
COMPRESSION DAMPING FORCE
1. Adjust:
• Compression damping force
Stiffer "a"
Softer "b"
Fully turned in
position
Minimum • STANDARD POSITION:
20 clicks out
(from maximum
position)
* For EUROPE
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
CHASSIS
By turning the adjuster "1".
→
Increase the com-
pression damping force. (Turn
the adjuster "1" in.)
→
Decrease the com-
pression damping force. (Turn
the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
20 clicks out
(from maximum
position)
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
Standard position:
12 clicks out
* 7 clicks out
Abnormal noise/unsmooth action
→
Grease the pivoting points or
repair the pivoting points.
→
Damage/oil leakage Replace.