Yamaha YZ450FP 2023, Owner'S Service Manual

Page: 109 / 388

CHASSIS
3-31
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove the bleed screw “1” and release the
internal pressure from the front fork.
3. Tighten:
•
Bleed screw
EAM30482
CHECKING THE REAR SHOCK ABSORBER
ASSEMBLY
1. Stand the vehicle upright on a level surface.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:
• Rear shock absorber assembly
Gas leaks/oil leaks

Replace the rear shock
absorber assembly.
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 4-63.
3. Check:
• Rear shock absorber assembly smooth ac-
tion
•
Rear suspension link smooth action
Sit astride the seat and shake your body up
and down several times to check whether the
rear shock absorber assembly operates
smoothly.
Unsmooth operation

Correct or replace.
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 4-63.
EAM30242
ADJUSTING THE REAR SHOCK ABSORBER
ASSEMBLY
Use a maintenance stand to raise the rear wheel
off the ground.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
Spring preload
NOTICE
ECA24360
Do not turn the adjuster forcibly beyond its
adjusting range.
1. Adjust:
•
Spring preload
a. Loosen the locknut “1”.
b. Loosen the adjuster “2” until there is some
clearance between the spring and the ad-
juster.
c. Measure the spring free length “a”.
d. Turn the adjuster in the direction of “b” or
“c” to make an adjustment.
TIP
• Be sure to remove all dirt and mud from around
the locknut and adjusting ring before adjust-
ment.
Bleed screw
1.3 N·m (0.13 kgf·m, 0.95 lb·ft)
T
R
.
.
1
Direction “b”
Spring preload is increased (suspen-
sion is harder).
Direction “c”
Spring preload is decreased (suspen-
sion is softer).
Spring preload adjusting positions
Minimum
Position in which the spring is
turned in 1.5 mm (0.06 in) from
its free length.
Standard
Position in which the spring is
turned in 7.0 mm (0.28 in) from
its free length.
Maximum
Position in which the spring is
turned in 18.0 mm (0.71 in) from
its free length.
1 1
2 2
a