Checking The Cylinder And Piston; Checking The Piston Rings - Yamaha 2007 FZ6-NA Service Manual

EAS24390

CHECKING THE CYLINDER AND PISTON

1. Check:
• Piston wall
• Cylinder wall
Vertical scratches → Replace the cylinder,
and replace the piston and piston rings as
a set.
2. Measure:
• Piston-to-cylinder clearance
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
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 mea-
surements.
Bore
65.500–65.510 mm (2.5787–
2.5791 in)
Wear limit
65.56 mm (2.5811 in)
Taper limit
0.050 mm (0.0020 in)
Out of round limit
0.050 mm (0.0020 in)
"C" = maximum of D
"T" = maximum of D
or D
6
"R" = maximum of D
D , D or D
2 4 6
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.
–D
1 6
or D - maximum of D
1 2
, D or D - minimum of
1 3 5
Piston size "P"
Standard
a. 4 mm (0.16 in) from the bottom edge of the
piston
d. If out of specification, replace the piston
and piston rings as a set.
e. Calculate the piston-to-cylinder clearance
with the following formula.
• Piston-to-cylinder clearance =
Cylinder bore "C" -
Piston skirt diameter "P"
Piston-to-cylinder clearance
5
Limit
f. If out of specification, replace the cylinder,
and the piston and piston rings as a set.
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EAS24430

CHECKING THE PISTON RINGS

1. Measure:
• Piston ring side clearance
Out of specification → Replace the piston
and piston rings as a set.
NOTE:
Before measuring the piston ring side clear-
ance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
5-63
CRANKSHAFT
65.475–65.490 mm (2.5778–
2.5783 in)
0.010–0.035 mm
0.0014 in)
0.05 mm (0.0020 in)
(0.0004–