Checking The Cylinder And Piston - Yamaha YZF-R1 Series Service Manual

3. Remove:
• Piston pin "1"
• Piston "2"
ECA13810
NOTICE
Do not use a hammer to drive the piston pin
out.
TIP
• For reference during installation, put identifica-
tion marks on the piston crown.
• Before removing the piston pin, deburr the pis-
ton pin clip groove 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 "3".
Piston pin puller set
90890-01304
Piston pin puller
YU-01304
2 1
G088998
4. Remove:
• Top ring
• 2nd ring
• Oil ring
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.
CONNECTING RODS AND PISTONS
1
3
G088999
EAS30747

CHECKING THE CYLINDER AND PISTON

1. Check:
• Piston wall
• Cylinder wall
Vertical scratches → Replace the cylinder
block, and replace the pistons and piston
rings as a set.
2. Measure:
• Piston-to-cylinder clearance
a. Measure cylinder bore "C" with the cylin-
der bore gauge.
TIP
Measure cylinder bore "C" by taking side-to-side
and front-to-back measurements of the cylinder.
Bore
79.000–79.010 mm (3.1102–
3.1106 in)
Wear limit
79.060 mm (3.1126 in)
"C" = maximum of D
G089000
b. If out of specification, replace the cylinder,
and replace the piston and piston rings as
a set.
c. Measure piston skirt diameter "P" with the
micrometer.
5-80
, D , D , D , D , D
1 2 3 4 5 6