Yamaha YZ125 2019 Owner's Service Manual page 79

4. Adjust:
• Spring preload
Adjustment steps:
a. Loosen the locknut "1".
b. Loosen the adjuster "2" until there is some
clearance between the spring and adjuster.
c. Measure the spring free length "a".
d. Turn the adjuster "2".
Stiffer →Increase the spring preload. (Turn
the adjuster "2" in.)
Softer → Decrease the spring preload.
(Turn the adjuster "2" out.)
Extent of adjustment:
Maximum
Position in which
the spring is turned
in 18 mm (0.71 in)
from its free length
• Be sure to remove all dirt and mud from
around the locknut and adjuster before adjust-
ment.
• The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
e. Tighten the locknut.
Locknut:
30 Nm (3.0 m•kg, 22 ft•lb)
5. Install:
• Rear frame (upper)
Rear frame (upper):
32 Nm (3.2 m•kg, 23 ft•lb)
Minimum
Position in which
the spring is turned
in 1.5 mm (0.06 in)
from its free length
3-24
• Rear frame (lower)
Rear frame (lower):
29 Nm (2.9 m•kg, 21 ft•lb)
ADJUSTING THE REAR SHOCK
ABSORBER REBOUND DAMPING FORCE
1. Adjust:
• Rebound damping force
By turning the adjuster "1".
Stiffer "a" → Increase the rebound damp-
ing force. (Turn the adjuster "1" in.)
Softer "b" → Decrease the rebound damp-
ing force. (Turn the adjuster "1" out.)
Extent of adjustment:
Maximum
Fully turned in posi-
tion
• STANDARD POSITION:
This is the position which is back by the spe-
cific number of clicks from the fully turned-in
position. (Which align the punch mark "a" on
the adjuster with the punch mark "b" on the
bracket.)
Standard position:
10–13 clicks out
Do not force the adjuster past the minimum
or maximum extent of adjustment. The ad-
juster may be damaged.
CHASSIS
Minimum
20 clicks out (from
maximum position)