Yamaha FJR13AEV(C), Service Manual

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CONNECTING RODS AND PISTONS
5-107
2. Install:
• Piston ring
(into the cylinder)
NOTE:
Level the piston ring into the cylinder with the
piston crown.
3. Measure:
• Piston ring end gap
Out of specification
→
Replace the piston
ring.
NOTE:
The oil ring expander spacer’s end gap cannot
be measured. If the oil ring rail’s gap is exces-
sive, replace all three piston rings.
EAS24440
CHECKING THE PISTON PIN
The following procedure applies to all of the pis-
ton pins.
1. Check:
• Piston pin
Blue discoloration/grooves
→
Replace the
piston pin and then check the lubrication sys-
tem.
2. Measure:
• Piston pin outside diameter “a”
Out of specification
→
Replace the piston pin.
3. Measure:
• Piston pin bore diameter “b”
Out of specification
→
Replace the piston.
4. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Out of specification
→
Replace the piston pin
and piston as a set.
a. 5 mm (0.20 in)
Piston ring
Top ring
End gap (installed)
0.35–0.45 mm (0.0138–0.0177
in)
Limit
0.70 mm (0.0276 in)
2nd ring
End gap (installed)
0.75–0.85 mm (0.0295–0.0335
in)
Limit
1.20 mm (0.0472 in)
Oil ring
End gap (installed)
0.20–0.60 mm (0.0079–0.0236
in)
Piston pin outside diameter
18.991–19.000 mm (0.7477–
0.7480 in)
Limit
18.971 mm (0.7469 in)
Piston pin bore inside diameter
19.004–19.015 mm (0.7482–
0.7486 in)
Limit
19.045 mm (0.7498 in)
• Piston-pin-to-piston-pin-bore clearance =
Piston pin bore diameter “b” -
Piston pin outside diameter “a”
Piston-pin-to-piston-pin-bore
clearance
0.004–0.024 mm (0.00016–
0.00094 in)