Yamaha 2007 XP500 - Checking the Piston Pin; Installing the Pistons and Cylinders

CYLINDER AND PISTONS
5-28
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.
EAS24470
INSTALLING THE PISTONS AND
CYLINDERS
The following procedure applies to all of the pis-
tons and cylinders.
1. Install:
● Top ring
● 2nd ring
● Oil ring
a. 10 mm (0.39 in)
Piston ring end gap
End gap (installed)
0.15–0.25 mm (0.0059–0.0098 in)
Limit
0.50 mm (0.0197 in)
End gap (installed)
0.40–0.50 mm (0.0157–0.0197 in)
Limit
0.75 mm (0.0295 in)
End gap (installed)
0.10–0.35 mm (0.0039–0.0138 in)
Piston pin outside diameter
14.991–15.000 mm
(0.5902–0.5906 in)
Limit
14.971 mm (0.5894 in)
Piston pin bore inside diameter
15.002–15.013 mm
(0.5906–0.5911 in)
Limit
15.043 mm (0.5922 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
0.002–0.022 mm
(0.00008–0.00087 in)
Limit: 0.072 mm (0.0028 in)