Removing The Drive Chain; Checking The Drive Chain - Yamaha YZ450F Owner's Service Manual

REMOVING THE DRIVE CHAIN

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1. Use a suitable stand to raise the rear wheel
off the ground.
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WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove:
• Joint clip
• Drive chain joint "1"
• Drive chain "2"

CHECKING THE DRIVE CHAIN

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1. Measure:
• 15-link section of the drive chain
Out of specification  Replace the drive
chain.
15-link length limit
242.9 mm (9.56 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 sec-
tion of the drive chain as shown in the illus-
tration.
b. Calculate the length "c" of the 15-link section
of the drive chain using the following formu-
la.
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. Check:
• Drive chain
Stiffness  Clean, lubricate, or replace.
3. 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.
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4-64
CHAIN DRIVE