Removing The Piston; Checking The Cylinder And Piston - Yamaha YFZ450S 2003 Service Manual

CYLINDER AND PISTON
EBS00247

REMOVING THE PISTON

1. Remove:
• piston pin clips 1
• piston pin 2
• piston 3
NOTE:
_
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 4.
Piston pin puller
CAUTION:
_
Do not use a hammer to drive the piston
pin out.
2. Remove:
• piston rings
NOTE:
_
Spread the end gaps apart while at the same
time lifting the piston ring over the top of the
piston crown, as shown in the illustration.
EBS00248

CHECKING THE CYLINDER AND PISTON

1. Check:
• piston wall
• cylinder wall
Vertical scratches → Replace the cylinder,
and the piston and piston rings as a set.
4 - 35
ENG
P/N. YU-01304, 90890-01304