Yamaha YZ250 2021, Owner'S Manual

Page: 101 / 148

CHAIN DRIVE
4-29
EAM20104
CHAIN DRIVE
EAM30556
REMOVING THE DRIVE CHAIN (for YZ250)
1. Use a maintenance stand to raise the rear
wheel off the ground.
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”
EAM30559
REMOVING THE DRIVE CHAIN (for YZ250X)
1. Stand the vehicle on a level surface.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
TIP
Place the vehicle on a maintenance stand so
that the rear wheel is elevated.
2. Remove:
• Drive chain
TIP
Cut the drive chain with the drive chain cut & riv-
et tool. (Use goods on the market.)
EAM30557
CHECKING THE DRIVE CHAIN (for YZ250)
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.
15-link length limit
242.9 mm (9.56 in) (YZ250)
1
2
3
G089068
G088937
G088938
G088939