Yamaha 2012 Grizzly 300 Service Manual page 143

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CYLINDER AND PISTON
EBS00247
REMOVING THE PISTON
1. Remove:
• piston pin clips
• piston pin
• piston
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TIP
• Before removing the piston pin clip, cover the
crankcase opening with a clean rag to prevent
the piston pin clip from falling into the crankcase.
• Before removing each piston pin, deburr the
clip groove and pin hole area. If the piston pin
groove is deburred and the piston pin is still
difficult to remove, use the piston pin puller
Piston pin puller set
P/N. YU-01304, 90890-01304
N O T I C E
Do not use a hammer to drive the piston
pin out.
2. Remove:
• piston rings
TIP
Spread the end gaps apart while at the same
time lifting the piston ring over the top of the
piston crown.
EBS00249
CHECKING THE CYLINDER AND PISTON
1. Check:
• piston wall
• cylinder wall
Vertical scratches
cylinder, and replace the piston and piston
rings as a set.
2. Measure:
• piston-to-cylinder clearance
a. Measure cylinder bore "C" with the cylinder
bore gauge.
TIP
_
Measure cylinder bore "C" by taking side-to-
side and front-to-back measurements of the
cylinder. Then, find the average of the mea-
surements.
4-23
ENG
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Rebore or replace the
.
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