Yamaha YZ450FA 2011 Owner's Service Manual page 313

• If the machine is new and after it is broken in,
the same set length of the spring may change
because of the initial fatigue, etc. of the
spring. Therefore, be sure to make reevalua-
tion.
• If the standard figure cannot be achieved by
adjusting the spring adjuster and changing
the spring set length, replace the spring with
an optional one and make readjustment.
SETTING OF SPRING AFTER
REPLACEMENT
After replacement, be sure to adjust the spring
to the set length [sunken length 90–100 mm
(3.5–3.9 in)] and set it.
1. Use of soft spring
• Set the soft spring for less rebound damping
to compensate for its less spring load. Run
with the rebound damping adjuster one or
two clicks on the softer side and readjust it to
suit your preference.
2. Use of stiff spring
• Set the soft spring for more rebound damp-
ing to compensate for its greater spring load.
Run with the rebound damping adjuster one
or two clicks on the stiffer side and readjust
it to suit your preference.
Adjusting the rebound damping will be followed
more or less by a change in the compression
damping. For correction, turn the low compres-
sion damping adjuster on the softer side.
When using a rear shock absorber other
than currently installed, use the one whose
overall length "a" does not exceed the stan-
dard as it may result in faulty performance.
Never use one whose overall length is
greater than standard.
Length "a" of standard shock:
459 mm (18.07 in)
REAR SHOCK ABSORBER SETTING
PARTS
• Rear shock spring "1"
SPRING
TYPE
RATE
SOFT 5.5
STD 5.7
STIFF 5.9
• The unequal-pitch spring is softer in initial
characteristic than the equal-pitch spring and
is difficult to bottom out under full compres-
sion.
• The I.D. mark "a" is marked at the end of the
spring.
• Spring specification varies according to the
color and quantity of I.D. marks.
8-4
CHASSIS
SPRING
PART I.D.
NUMBER MARK
(-22212-)
33D-20
(Blue)
Pink
33D-C0
(Red)
33D-30
(Blue)
White
33D-D0
(Red)
33D-40
(Blue)
Silver
33D-E0
(Red)