Cylinder And Piston; Removing The Cylinder And Piston; Checking The Cylinder And Piston - Yamaha YBR250 2007 Service Manual

1
2
3
4

CYLINDER AND PISTON

REMOVING THE CYLINDER AND PISTON

1. Remove:
3
• piston pin circlips 1
• piston pin 2
• piston 3
2
CAUTION:
Do not use a hammer to drive the piston pin
out.
NOTE:
• 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 the piston pin, deburr the piston
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
2. Remove:
• top ring
• 2nd ring
• oil ring
NOTE:
To remove a piston ring, open the end gap with
your fingers and lift the other side of the ring over
the piston crown.

CHECKING THE CYLINDER AND PISTON

1. Check:
• piston wall
• cylinder wall
Vertical scretches --> Replace the cylinder
and piston and the piston rings as a set.
5-31
90890-01304
ENG