Yamaha YZ125X 2021, Owner'S Service Manual

Page: 81 / 268

CHASSIS
3-17
Adjusting the drive chain slack
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
1. Adjust:
•
Drive chain slack
a. Loosen the wheel axle nut “1”.
b. Loosen both locknuts “2”.
c. Turn the adjusting bolt “3” until the speci-
fied drive chain slack is obtained.
TIP
•
To maintain the proper wheel alignment, adjust
both sides evenly.
•
Push the rear wheel forward to make sure that
there is no clearance between the swingarm
end plates and the ends of the swingarm.
d. Tighten the wheel axle nut.
e. Tighten the drive chain puller locknut.
EAM30251
LUBRICATING THE DRIVE CHAIN
The drive chain consists of many interacting
parts. If the drive chain is not maintained proper-
ly, it will wear out quickly. Therefore, the drive
chain should be serviced, especially when the
vehicle is used in dusty areas.
This vehicle has a drive chain with small rubber
O-rings between each side plate. Steam clean-
ing, high-pressure washing, certain solvents,
and the use of a coarse brush can damage
these O-rings. Therefore, use only kerosene to
clean the drive chain. Wipe the drive chain dry
and thoroughly lubricate it with engine oil or
chain lubricant that is suitable for O-ring chains.
Do not use any other lubricants on the drive
chain since they may contain solvents that could
damage the O-rings.
EAM30247
CHECKING AND ADJUSTING THE
STEERING HEAD
1. Use a maintenance stand to raise the front
wheel off the ground.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:
•
Steering head
Grasp the bottom of the front fork legs and
gently rock the front fork.
Blinding/looseness

Adjust the steering
head.
3. Remove:
•
Handlebar
Refer to “HANDLEBAR” on page 4-32.
• Upper bracket
Refer to “STEERING HEAD” on page 4-50.
4. Adjust:
•
Steering head
a. Remove the washer “1”.
Drive chain slack (Maintenance
stand)
48.0–58.0 mm (1.89–2.28 in)
Rear wheel axle nut
125 N·m (12.5 kgf·m, 92 lb·ft)
Drive chain puller locknut
19 N·m (1.9 kgf·m, 14 lb·ft)
2
1
3
T
R
.
.
T
R
.
.
Recommended lubricant
Chain lubricant suitable for O-
ring chains