Yamaha YZ450FX 2019 Owner's Service Manual page 172

Base valve
28 N·m (2.8 kgf·m, 21 lb·ft)
TIP
Hold the damper assembly with the cap bolt ring
wrench "2" and use the cap bolt wrench "3" to
tighten the base valve.
Cap bolt wrench
90890-01500
Cap bolt wrench
YM-01500
Cap bolt ring wrench
90890-01501
Cap bolt ring wrench
YM-01501
3
2
10.After filling, pump the damper assembly "1"
slowly up and down more than 10 times to
distribute the fork oil.
1
11.While protecting the damper assembly "1"
with a cloth and compressing fully, allow ex-
cessive oil to overflow on the base valve side.
ECA24540
NOTICE
Take care not to damage the damper assem-
bly.
1
4-44
1
12.Allow the overflowing oil to escape at the hole
"a" in the damper assembly.
TIP
The overflow measures about 10 cm³ (0.34 US
oz, 0.35 Imp.oz).
a
13.Check:
• Damper assembly smooth movement
Tightness/binding/rough spots  Repeat the
steps (1) to (12).
14.Install:
• Dust seal "1"
New
• Oil seal clip "2"
• Oil seal "3"
New
• Washer "4"
• Outer tube bushing "5"
(to the inner tube "6")
ECA24550
NOTICE
Make sure that the numbered side of the oil
seal faces bottom side.
FRONT FORK
New