Yamaha YZ450FX 2023, Owner'S Manual

Page: 100 / 164

FRONT FORK
4-18
EAM30058
ASSEMBLING THE FRONT FORK LEGS
WARNING
EWA13660
• Make sure the oil levels in both front fork
legs are equal.
• Uneven oil levels can result in poor han-
dling and a loss of stability.
TIP
•
When assembling the front fork leg, be sure to
replace the following parts:
•
Inner tube bushing
• Slide metal
•
Oil seal
• Copper washer
•
Before assembling the front fork leg, make
sure that all of the components are clean.
1. Stretch the damper assembly fully.
2. Fill:
•
Damper assembly
NOTICE
ECA24530
• Be sure to use the recommended oil. Other
oils may have an adverse effect on front
fork performance.
• When disassembling and assembling the
front fork leg, take care not to allow any for-
eign material to enter the front fork.
3. After filling, pump the damper assembly “1”
slowly up and down (about 200 mm (7.9 in)
stroke) several times to bleed the damper as-
sembly of air.
TIP
Avoid excessive full stroke. A stroke of 200 mm
(7.9 in) or more will cause air to enter. In this
case, repeat the steps (1) to (3).
4. Measure:
•
Oil level (left and right) “a”
Out of specification

Regulate.
5. Tighten:
•
Locknut “1”
TIP
Fully finger tighten the locknut onto the damper
assembly.
6. Loosen:
• Compression damping force adjuster “1”
TIP
• Before loosening the damping force adjuster,
record the setting position.
• Unless the damping force adjuster is fully loos-
ened, correct damping characteristic cannot be
Recommended oil
Yamaha Suspension Oil S1
Standard oil amount
216 cm³ (7.30 US oz, 7.62 Imp.oz)
1
Standard oil level
145–148 mm (5.71–5.83 in)
From top of fully stretched
damper assembly.
a