Yamaha WR450FB 2012, Owner'S Service Manual

Page: 125 / 392

CHASSIS
4-2
• Under a stony or hard road condition, the tire
pressure should be higher to prevent a flat
tire.
EAS1DX3128
FRONT FORK SETTING
The front fork setting should be made depend-
ing on the rider's feeling of an actual run and
the circuit conditions.
The front fork setting includes the following
three factors:
1. Setting of air spring characteristics
• Change the fork oil amount.
2. Setting of spring preload
• Change the spring.
3. Setting of damping force
• Change the compression damping.
• Change the rebound damping.
The spring acts on the load and the damping
force acts on the cushion travel speed.
EAS1DX3129
CHANGE IN AMOUNT AND CHARACTERIS-
TICS OF FORK OIL
Damping characteristic near the final stroke
can be changed by changing the fork oil
amount.
EWA1DX4001
WARNING
Adjust the oil amount in 5 cm
3
(0.2 Imp oz,
0.2 US oz) increments or decrements. Too
small oil amount causes the front fork to
produce a noise at full rebound or the rider
to feel some pressure on his hands or body.
Alternatively, too large oil amount will
cause the air spring characteristics to have
a tendency to be stiffer with the consequent
deteriorated performance and characteris-
tics. Therefore, adjust the front fork within
the specified range.
EAS1DX3130
SETTING OF SPRING AFTER REPLACE-
MENT
As the front fork setting can be easily affected
by rear suspension, take care so that the ma-
chine front and rear are balanced (in position,
etc.) when setting the front fork.
1. Use of soft spring
• Change the rebound damping.
Turn out one or two clicks.
• Change the compression damping.
Turn in one or two clicks.
TIP
Generally a soft spring gives a soft riding feel-
ing. Rebound damping tends to become stron-
ger and the front fork may sink deeply over a
series of gaps.
2. Use of stiff spring
• Change the rebound damping.
Turn in one or two clicks.
• Change the compression damping.
Turn out one or two clicks.
Extent of adjustment:
100–120 kPa (1.0–1.2 kgf/
cm
2
,15–18 psi)
Standard oil amount:
328 cm
3
(11.55 lmp.oz, 11.09 US
oz)
Extent of adjustment
295–370 cm
3
(10.38–13.02 lmp.
oz, 9.97–12.51 US oz)
A. Air spring characteristics in relation to oil
amount change
B. Load
C. Stroke
1. Max. oil amount
2. Standard oil amount
3. Min. oil amount