Yamaha YZ250 2021, Owner'S Manual

Page: 141 / 148

CHASSIS
8-12
the same set length of the spring may change
because of the initial fatigue, etc. of the spring.
Therefore, be sure to make reevaluation.
• If the standard figure cannot be achieved by
adjusting the adjuster and changing the set
length, replace the spring with an optional one
and make readjustment.
EAM30177
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
•
Adjust to decrease rebound damping force to
compensate for less spring load. Run with the
rebound damping force adjuster one or two
clicks turned out, and readjust it to suit your
preference.
2. Use of stiff spring
•
Adjust to increase rebound damping force to
compensate for greater spring load. Run with
the rebound damping force adjuster one or
two clicks turned in, and readjust it to suit your
preference.
TIP
Adjusting the rebound damping force will be fol-
lowed more or less by a change in the compres-
sion damping force. For correction, adjust to
decrease compression damping force.
WARNING
EWA19200
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 great-
er than standard.
EAM30178
REAR SHOCK ABSORBER SETTING PARTS
• Rear shock spring “1”
[Equal-pitch steel spring]
[Unequal-pitch steel spring]
TIP
•
The unequal-pitch spring is softer in initial char-
acteristic than the equal-pitch spring and is dif-
ficult to bottom out under full compression.
• The I.D. mark “a” is marked at the end of the
spring.
• Spring specification varies according to the
Length “a” of standard shock
490 mm (19.29 in)
STD spring rate
(N/mm)
48
Type
Spring
rate
(N/mm)
Part number
I.D.
mark/Q’ty
SOFT 42 5UN-22212-00 Brown/1
44 5UN-22212-10 Green/1
46 5UN-22212-20 Red/1
48 5UN-22212-30 Black/1
50 5UN-22212-40 Blue/1
52 5UN-22212-50 Yellow/1
54 5UN-22212-60 Pink/1
STIFF 56 5UN-22212-70 White/1
Type
Spring
rate
(N/mm)
Part number
I.D.
mark/Q’ty
SOFT 44 5UN-22212-A0 Green/2
46 5UN-22212-B0 Red/2
48 5UN-22212-C0 Black/2
50 5UN-22212-D0 Blue/2
52 5UN-22212-E0 Yellow/2
54 5UN-22212-F0 Pink/2
STIFF 56 5UN-22212-G0 White/2