Yamaha YZ450F, Owner'S Service Manual

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T U N
SETTING
EC72H002
Suspension setting
• Front fork
NOTE:
• If any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
• Before any change, set the rear shock absorber sunken length to the standard figure 90 ~ 100 mm
(3.5 ~ 3.9 in).
Symptom
Section
Check Adjust
Jump
Large
gap
Medium
gap
Small
gap
Stiff over entire range
Compression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil amount Decrease oil amount by about 5 ~ 10 cm
3
(0.2 ~
0.4 Imp oz, 0.2 ~ 0.3 US oz).
Spring Replace with soft spring.
Unsmooth movement
over entire range
Outer tube Check for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Inner tube
Slide metal Replace with a new one for extended use.
Piston metal Replace with a new one for extended use.
Under bracket tightening
torque Retighten to specified torque.
Poor initial
movement
Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil seal Apply grease in oil seal wall.
Soft over entire
range, bottoming out
Compression damping Turn adjuster clockwise (about 2 clicks) to increase
damping.
Oil amount Increase oil amount by about 5 ~ 10 cm
3
(0.2 ~
0.4 Imp oz, 0.2 ~ 0.3 US oz).
Spring Replace with stiff spring.
Stiff toward stroke
end
Oil amount
Decrease oil amount by about 5 cm
3
(0.2 Imp oz,
0.2 US oz).
Soft toward stroke
end, bottoming out
Oil amount
Increase oil amount by about 5 cm
3
(0.2 Imp oz,
0.2 US oz).
Stiff initial movement Compression damping
Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture
Compression damping Turn adjuster clockwise (about 2 clicks) to increase
damping.
Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Balance with rear end Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when
one passenger is astride seat (lower rear posture).
Oil amount Increase oil amount by about 5 cm
3
(0.2 Imp oz,
0.2 US oz).
“Obtrusive” front,
tending to upper front
posture
Compression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Balance with rear end Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in)
when one passenger is astride seat (upper rear pos-
ture).
Spring Replace with soft spring.
Oil amount Decrease oil amount by about 5 ~ 10 cm
3
(0.2 ~
0.4 Imp oz, 0.2 ~ 0.3 US oz).