Yamaha YZ450F Owner's Service Manual page 226

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 re-
bound 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 re-
bound damping to compensate
for its greater spring load. Run
with the rebound damping adjust-
er 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 cor-
rection, turn the low compression
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 standard 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"
SPRI SPRING
NG PART
TYPE
RAT NUMBER
E (-22212-)
33D-20
(Blue)
SOFT 5.5
33D-C0
(Red)
33D-30
(Blue)
5.7
STD
33D-D0
(Red)
33D-40
(Blue)
STIFF
5.9
33D-E0
(Red)
• The unequal-pitch spring is softer in
initial characteristic than the equal-
pitch spring and is difficult to bottom
out under full compression.
• The I.D. mark "a" is marked at the
end of the spring.
• Spring specification varies accord-
ing to the color and quantity of I.D.
marks.
8-3
• Extent of adjustment (spring pre-
load)
Maximum
Position in
I.D.
which the
MARK
spring is turned
in 18 mm (0.71
in) from its free
length.
Pink
• For the spring preload adjustment,
refer to "ADJUSTING THE REAR
SHOCK ABSORBER SPRING
PRELOAD" in the CHAPTER 3.
White
• Preload adjusting extent is the
same for the titanium and steel
springs.
Silver
CHASSIS
Minimum
Position in
which the
spring is turned
in 1.5 mm (0.06
in) from its free
length.