2005 YAMAHA YZ250F oil pressure

4 - 55
ENGCLUTCH
7. Install:
Push rod 2 1
Ball 2
Push rod 1 3
NOTE:
Apply the engine oil on the push rod 1, 2 and
ball.
8. Install:
Pressure plate 1
9. Install:
Clutch spring 1
Bolt (clutch spring) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..8 Nm (0.8 m · kg, 5.8 ft · lb)
10. Install:
Dowel pin 1
Gasket (clutch cover) 2
11. Install:
Clutch cover 1
Bolt (clutch cover)
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

5 - 33
CHASFRONT FORK
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.
5. Inspect:
Oil amount
While keeping the damper assembly fully
stretched, check that the oil is above the
step a on the damper assembly.
Below the step → Replenish fork oil
above the step.
6. Tighten:
Locknut 1
NOTE:
Fully finger tighten the locknut onto the
damper assembly.
7. Loosen:
Compression damping adjuster 1
NOTE:
Loosen the compression damping adjuster
finger tight.
Record the set position of the adjuster (the
amount of turning out the fully turned in posi-
tion).
8. Install:
Base 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.

5 - 63
CHAS
HANDLING NOTE
WARNING
This rear shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of
explosion, read and understand the follow-
ing information before handling the shock
absorber.
The manufacturer can not be held respon-
sible for property damage or personal
injury that may result from improper han-
dling.
1. Never tamper or attempt to disassemble
the cylinder or the tank.
2. Never throw the rear shock absorber
into an open flame or other high heat.
The rear shock absorber may explode as
a result of nitrogen gas expansion and/
or damage to the hose.
3. Be careful not to damage any part of the
gas tank. A damaged gas tank will impair
the damping performance or cause a
malfunction.
4. Take care not to scratch the contact sur-
face of the piston rod with the cylinder;
or oil could leak out.
5. Never attempt to remove the plug at the
bottom of the nitrogen gas tank. It is
very dangerous to remove the plug.
6. When scrapping the rear shock
absorber, follow the instructions on dis-
posal.
NOTES ON DISPOSAL (YAMAHA DEALERS
ONLY)
Before disposing the rear shock absorber, be
sure to extract the nitrogen gas from valve 1.
Wear eye protection to prevent eye damage
from escaping gas and/or metal chips.
WARNING
To dispose of a damaged or worn-out rear
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
REAR SHOCK ABSORBER

7 - 13
TUNSETTING
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.
Install the adjustment washer.
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.
Change in amount and characteristics of
fork oil
Damping characteristic near the final stroke
can be changed by changing the fork oil
amount.
CAUTION:
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 develop unexpectedly early oil lock
with the consequent shorter front fork
travel and deteriorated performance and
characteristics. Therefore, adjust the front
fork within the specified range.
ÈAir spring characteristics in relation to oil amount
change
ÉLoad
ÊStroke
1Max. oil amount
2Standard oil amount
3Min. oil amount
Standard oil amount:
245 cm3
(8.62 Imp oz, 8.28 US oz)
Extent of adjustment:
200 ~ 300 cm
3
(7.04 ~ 10.6 Imp oz,
6.76 ~ 10.1 US oz)