Removing The Piston; Checking The Cylinder And Piston - Yamaha Grizzly550 User Manual

EAS24380

REMOVING THE PISTON

1. Remove:
• Piston pin clips "1"
• Piston pin "2"
• Piston "3"
ECA13810
NOTICE
Do not use a hammer to drive the piston pin
out.
TIP
• Before removing the piston pin clips, cover the
crankcase opening with a clean rag to prevent
the piston pin clips from falling into the crank-
case.
• Before removing the piston pin, deburr the pis-
ton pin clip grooves and the piston pin bore ar-
ea. If both areas are deburred and the piston
pin is still difficult to remove, remove it with the
piston pin puller set "4".
Piston pin puller set
90890-01304
Piston pin puller
YU-01304
2
3
2. Remove:
• Top ring
• 2nd ring
• Oil ring
1
5-29
CYLINDER AND PISTON
TIP
When removing a piston ring, open the end gap
with your fingers and lift the other side of the ring
over the piston crown.
EAS24400

CHECKING THE CYLINDER AND PISTON

1. Check:
• Piston wall
• Cylinder wall
Vertical scratches → Replace the cylinder,
and replace the piston and piston rings as a
set.
2. Measure:
• Piston-to-cylinder clearance
M MMM M MMM M M MMM M M MMM M
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 measurements.
M MMM M M MMM M MMM