Removing The Piston; Checking The Cylinder And Piston - Yamaha YFM660FS Grizzly 4x4 Supplementary Service Manual

CYLINDER AND PISTON

REMOVING THE PISTON

1.Remove:
Piston pin clips 1
G
Piston pin 2
G
Piston 3
G
NOTE:
Put identification marks on each piston head
G
for reference during reinstallation.
Before removing each piston pin, deburr the
G
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:
P/N. YU-01304, 90890-01304
CAUTION:
Do not use a hammer to drive the piston
pin out.
2.Remove:
Piston rings
G
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.

CHECKING THE CYLINDER AND PISTON

1.Check:
Cylinder and piston walls
G
Vertical scratches → Rebore or replace the
cylinder and the piston.
2.Measure:
Piston-to-cylinder clearance
G
*****************************************************
Measurement steps:
1st step:
G
Measure the cylinder bore "C" with a cylinder
bore gauge 1.
a 50 mm (2.0 in) from the top of the cylinder
4 - 33
ENG