Yamaha YZ250 2022, Owner'S Service Manual

Page: 159 / 274

CHAIN DRIVE
4-65
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 4-8.
EAM30079
INSTALLING THE DRIVE CHAIN
1. Install:
•
Master link “1”
• Master link plate “2”
•
Master link clip “3”
NOTICE
ECA14310
• The closed end of the master link clip must
face in the direction of drive chain rotation.
• Never install a new drive chain onto worn
drive chain sprockets; this will dramatically
shorten the drive chain’s life.
2. Lubricate:
• Drive chain
3. Install:
• Drive sprocket
•
Lock washer
• Drive sprocket nut
Refer to “ENGINE REMOVAL” on page 5-1.
NOTICE
ECA14300
Never install a new drive chain onto worn
drive chain sprockets; this will dramatically
shorten the drive chain’s life.
4. Adjust:
•
Drive chain slack
Refer to “DRIVE CHAIN SLACK” on page
3-16.
NOTICE
ECA24590
A drive chain that is too tight will overload
the engine and other vital parts, and one that
is too loose can skip and damage the swing-
arm or cause an accident. Therefore, keep
the drive chain slack within the specified lim-
its.
b. Correct
1. Drive chain roller
2. Drive sprocket
2
1
G088942
G088904
Ne w
Drive sprocket nut
75 N·m (7.5 kgf·m, 55 lb·ft)
Drive chain slack (Maintenance
Stand)
48.0–58.0 mm (1.89–2.28 in)
1
2
G089069
3
G089070
Ne w
T
R
.
.