Yamaha YZ250 2021 Owner's Manual page 105

2. Lubricate:
• Drive chain
Recommended lubricant
Chain lubricant suitable for O-
ring chains
3. Install:
• Drive sprocket
• Lock washer
New
• Drive sprocket nut
Drive sprocket nut
75 N·m (7.5 kgf·m, 55 lb·ft)
ECA14300
NOTICE
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.
Drive chain slack (Maintenance
stand)
48.0–58.0 mm (1.89–2.28 in)
ECA24590
NOTICE
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.
4-33
CHAIN DRIVE