Yamaha YZ250 2022, Owner'S Service Manual

Page: 158 / 274

CHAIN DRIVE
4-64
EAM30075
REMOVING THE DRIVE CHAIN
1. Stand the vehicle on a level surface.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove:
• Master link clip
•
Master link “1”
• Master link plate “2”
•
Drive chain “3”
EAM30076
CHECKING THE DRIVE CHAIN
1. Measure:
•
15-link section of the drive chain
Out of specification

Replace the drive
chain.
a. Measure the length “a” between the inner
sides of the pins and the length “b” be-
tween the outer sides of the pins on a 15-
link section of the drive chain as shown in
the illustration.
b. Calculate the length “c” of the 15-link sec-
tion of the drive chain using the following
formula.
Drive chain 15-link section length “c” =
(length “a” between pin inner sides +
length “b” between pin outer sides)/2
TIP
• When measuring a 15-link section of the drive
chain, make sure that the drive chain is taut.
• Perform this procedure 2–3 times, at a different
location each time.
2. Check:
• Drive chain
Stiffness

Clean, lubricate, or replace.
3. Clean:
•
Drive chain
a. Wipe the drive chain with a clean cloth.
b. Put the drive chain in kerosene and re-
move any remaining dirt.
c. Remove the drive chain from the kerosene
and completely dry it.
4. Check:
•
Drive chain roller “1”
Damage/wear

Replace the drive chain.
•
Drive chain side plate “2”
Damage/wear

Replace the drive chain.
15-link length limit
242.9 mm (9.56 in)
1
2
3
G089068
G088937
G088938
G088939
G088940