Yamaha 2006 FZ1-N, Service Manual

Page: 271 / 451

CRANKSHAFT
5-73
NOTE:
Identify the position of each crankshaft journal
upper bearing so that it can be reinstalled in its
original place.
ET2D1032
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.
2. Measure:
• Piston-to-cylinder clearance
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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.
b. If out of specification, replace the cylinder,
and the pistons and piston rings as a set.
c. Measure piston skirt diameter “P” with the
micrometer.
4 mm (0.16 in) “a” 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.
f. If out of specification, replace the cylinder,
and the piston and piston rings as a set.
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ET2D1015
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.
Cylinder bore “C” 77.00 – 77.01 mm
(3.0315 – 3.0319 in)
Wear limit 77.06 mm (3.03 in)
Taper limit “T” 0.005 mm (0.0002 in)
Out of round “R” 0.005 mm (0.0002 in)
“C” = maximum of D
1
– D
6
“T” = maximum of D
1
or D
2
– maximum
of D
5
or D
6
“R” = maximum of D
1
D
3
or D
5
–
minimum of D
2
D
4
or D
6
Piston size “P”
76.975 - 76.990 mm
(3.0305 - 3.0311 in)
Piston-to-cylinder clearance =
Cylinder bore “C” –
Piston skirt diameter “P”
Piston-to-cylinder clearance
0.010–0.035 mm
(0.0004–0.0014 in)
Limit: 0.120 mm (0.0047 in)