Yamaha RAPTOR YFM125RA Service Manual page 158

EAS23410
REMOVING THE DRIVE CHAIN
1. Place the vehicle on a level surface.
EWA13120
WARNING
Securely support the vehicle so that there
is no danger of it falling over.
TIP
Place the vehicle on a suitable stand so that
the rear wheel is elevated.
2. Remove:
• Swingarm
Refer to "SWINGARM" on page 4-55.
3. Remove:
• Drive chain
EAS23441
CHECKING THE DRIVE CHAIN
1. Measure:
• 15-link section "a" of the drive chain
Out of specification → Replace the drive
chain.
15-link length limit
191.5 mm (7.54 in)
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a. Measure the length "a" between the inner
sides of the pins and the length "b"
between 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 differ-
ent location each time.
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2. Clean:
• Drive chain
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a. Wipe the drive chain with a clean cloth.
b. Put the drive chain in kerosene and remove
any remaining dirt.
c. Remove the drive chain from the kerosene
and completely dry it.
ECA14290
• This vehicle has a drive chain with small
rubber O-rings "1" between the drive
chain side plates. Never use high-pres-
sure water or air, steam, gasoline, certain
solvents (e.g., benzine), or a coarse brush
to clean the drive chain. High-pressure
methods could force dirt or water into the
drive chain's internals, and solvents will
deteriorate the O-rings. A coarse brush
can also damage the O-rings. Therefore,
use only kerosene to clean the drive
chain.
• Do not soak the drive chain in kerosene
for more than ten minutes, otherwise the
O-rings can be damaged.
4-59
CHAIN DRIVE