Yamaha YZ250N Owner's Service Manual page 178

SPROCKETS INSPECTION/DRIVE CHAIN INSPECTION
EC368000
SPROCKETS INSPECTION
1. Inspect:
9Sprocket teeth a
Excessive wear
NOTE:
Replace the drive, driven sprockets and drive
chain as a set.
EC369002
DRIVE CHAIN INSPECTION
1. Remove:
9Master link clip
9Joint 1
9Drive chain 2
2. Clean:
9Drive chain
Place it in kerosene, and brush off as much
dirt as possible. Then remove the chain
from the kerosene and dry the chain.
3. Measure:
9Drive chain length (10 links) a
Out of specification Replace.
Drive chain length (10 links):
Limit: 152.5 mm (6.004 in)
4. Check:
9Drive chain stiffness a
Clean and oil the chain and hold as
illustrated.
Stiff Replace drive chain.
3-24
INSP
ADJ
Replace.