Cylinder And Pistons; Removing The Piston; Checking The Cylinders And Pistons - Yamaha 2007 XP500 Service Manual

EAS24380

REMOVING THE PISTON

The following procedure applies to all of the pis-
tons.
1. Remove:
Piston pin clips "1"
G
Piston pin "2"
G
Piston "3"
G
ECA13810
CAUTION:
Do not use a hammer to drive the piston pin
out.
NOTE:
Before removing the piston pin clip, cover the
G
crankcase opening with a clean rag to prevent
the piston pin clip from falling into the crank-
case.
Before removing the piston pin, deburr the pis-
G
ton pin clip's groove and the piston's pin bore
area. 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. Remove:
Top ring
G
2nd ring
G
Oil ring
G

CYLINDER AND PISTONS

NOTE:
When removing a piston ring, open the end gap
with your fingers and lift the other side of the ring
over the piston crown.
EAS15B4256

CHECKING THE CYLINDERS AND PISTONS

The following procedure applies to all of the cyl-
inders and pistons.
1. Check:
Piston wall
G
Cylinder wall
G
Vertical scratches → Rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
2. Measure:
Piston-to-cylinder clearance
G
MMMMMMMMMMMMMMMMMMMMMM
a. Measure cylinder bore "C" with the cylinder
bore gauge.
NOTE:
Measure cylinder bore "C" by taking side-to-side
and front-to-back measurements of the cylinder.
Then, find the average of the measurements.
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