Yamaha WR250FM 2021, Owner'S Service Manual

Page: 197 / 404

CHAIN DRIVE
4-71
4. Check:
• O-ring “1”
Damage

Replace the drive chain.
• Drive chain roller “2”
Damage/wear

Replace the drive chain.
• Drive chain side plate “3”
Damage/wear

Replace the drive chain.
5. Lubricate:
• Drive chain
EAM30077
CHECKING THE DRIVE SPROCKET
1. Check:
•
Drive sprocket
More than 1/4 tooth wear “a”

Replace the
drive sprocket and the rear wheel sprocket as
a set.
Bent tooth

Replace the drive sprocket and
the rear wheel sprocket as a set.
EAM30078
CHECKING THE REAR WHEEL SPROCKET
Refer to “CHECKING AND REPLACING THE
REAR WHEEL SPROCKET” on page 4-13.
EAM30079
INSTALLING THE DRIVE CHAIN
1. Install:
•
Drive chain
NOTICE
ECA17410
Be sure to put on safety goggles when work-
ing.
TIP
Install the master link with the drive chain cut &
rivet tool. (Use goods on the market.)
a. When press fitting the master link plate
“1”, make sure the space “a” between the
end of the connecting pin “2” and the mas-
ter link plate is 1.2–1.4 mm (0.05–0.06 in).
b. After riveting, make sure the diameter be-
tween the edges “b” of the connecting pin
“2” is 5.5–5.8 mm (0.22–0.23 in).
Recommended lubricant
Chain lubricant suitable for O-
ring chains
b. Correct
1. Drive chain roller
2. Drive sprocket