2005 YAMAHA YZ450F oil

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 - 34
CHASFRONT FORK
9. Tighten:
Base valve 1
NOTE:
Hold the damper assembly with the cap bolt
ring wrench 2 and use the cap bolt wrench 3
to tighten the base valve with specified torque.
Cap bolt wrench:
YM-01500/90890-01500
Cap bolt ring wrench:
YM-01501/90890-01501
T R..29 Nm (2.9 m · kg, 21 ft · lb)
10. After filling, pump the damper assembly 1
slowly up and down more than 10 times to
distribute the fork oil.
11. While protecting the damper assembly 1
with a rag and compressing fully, allow
excessive oil to overflow on the base valve
side.
CAUTION:
Take care not to damage the damper
assembly.
12. Allow the overflowing oil to escape at the
hole a in the damper assembly.

5 - 35
CHASFRONT FORK
13. Check:
Damper assembly smooth movement
Tightness/binding/rough spots → Repeat
the steps 2 to 12.
14. Install:
Dust seal 1
Stopper ring 2
Oil seal 3
Oil seal washer 4
Slide metal 5
To inner tube 6.
NOTE:
Apply the fork oil on the inner tube.
When installing the oil seal, use vinyl seat a
with fork oil applied to protect the oil seal lip.
Install the oil seal with its manufacture’s
marks or number facing the axle holder side.
Install the oil seal washer with its projections
b facing upward.
New
New
15. Install:
Piston metal 1
NOTE:
Install the piston metal onto the slot on inner
tube.
New
16. Install:
Outer tube 1
To inner tube 2.

5 - 36
CHASFRONT FORK
17. Install:
Slide metal 1
Oil seal washer 2
To outer tube slot.
NOTE:
Press the slide metal into the outer tube with
fork seal driver 3.
Fork seal driver:
YM-01442/90890-01442
18. Install:
Oil seal 1
NOTE:
Press the oil seal into the outer tube with fork
seal driver 2.
Fork seal driver:
YM-01442/90890-01442
19. Install:
Stopper ring 1
NOTE:
Fit the stopper ring correctly in the groove in
the outer tube.
20. Install:
Dust seal 1
NOTE:
Apply the lithium soap base grease on the
inner tube.

5 - 39
CHAS
29. Install:
Adjuster 1
To inner tube.
T R..55 Nm (5.5 m · kg, 40 ft · lb)
30. Fill:
Front fork oil 1
From outer tube top.
* For EUROPE
WARNING
Never fail to make the oil amount adjust-
ment between the maximum and minimum
amount and always adjust each front fork
to the same setting. Uneven adjustment
can cause poor handling and loss of stabil-
ity.
CAUTION:
Be sure to use recommended fork oil. If
other oils are used, they may have an
excessively adverse effect on the front
fork performance.
Never allow foreign materials to enter the
front fork.
Recommended oil:
Suspension oil “S1”
Standard oil amount:
260 cm
3 (9.15 Imp oz, 8.79 US oz)
*270 cm3 (9.50 Imp oz, 9.13 US oz)
Extent of adjustment:
200 ~ 300 cm
3
(7.04 ~ 10.6 Imp oz,
6.76 ~ 10.1 US oz)
31. Install:
Damper assembly 1
To outer tube.
NOTE:
Temporarily tighten the damper assembly.
FRONT FORK

5 - 44
CHASHANDLEBAR
EC5B5000
ASSEMBLY AND INSTALLATION
Handlebar
1. Install:
Handlebar 1
Handlebar holder 2
Bolt (handlebar holder) 3
NOTE:
The upper handlebar holder should be
installed with the punched mark a forward.
Install the handlebar so that the marks b are
in place on both sides.
First tighten the bolts on the front side of the
handlebar holder, and then tighten the bolts
on the rear side.
T R..28 Nm (2.8 m · kg, 20 ft · lb)
2. Install:
Grip (left) 1
Apply the adhesive to the handlebar 2.
NOTE:
Before applying the adhesive, wipe off
grease or oil on the handlebar surface a
with a lacquer thinner.
Install the grip (left) to the handlebar so that
the line b between the two arrow marks
faces straight upward.

5 - 45
CHASHANDLEBAR
3. Install:
Grip (right) 1
Collar 2
Apply the adhesive on the tube guide 3.
NOTE:
Before applying the adhesive, wipe off
grease or oil on the tube guide surface a
with a lacquer thinner.
Install the grip to the tube guide so that the
grip match mark b and tube guide slot c
form the angle as shown.
R
L
90˚
3 1b
c
4. Install:
Collar 1
Cover (grip cap) 2
Throttle grip 3
NOTE:
Apply the lithium soap base grease on the
throttle grip sliding surface.
5. Install:
Throttle cables 1
To tube guide 2.
NOTE:
Apply the lithium soap base grease on the
throttle cable end and tube guide cable wind-
ing portion.

5 - 54
CHASSWINGARM
EC578000
SWINGARM DISASSEMBLY
Extent of removal:
1 Swingarm disassembly
2 Connecting rod removal and disassembly
3 Relay arm removal and disassembly
Extent of removal Order Part name Q’ty Remarks
SWINGARM DISASSEMBLY
1 Cap 2 Refer to “REMOVAL POINTS”.
2 Relay arm 1
3 Connecting rod 1
4 Collar 2
5 Oil seal 2
6 Thrust bearing 2
7 Bush 2
8 Oil seal 8
9 Bearing 10 Refer to “REMOVAL POINTS”.
1
2
32
3