Checking The Piston Pins; Installing The Pistons And Cylinder - Yamaha 2009 XP500Y TMAX Service Manual

3. Measure:
• Piston ring end gap
Out of specification → Replace the piston
ring.
TIP
The oil ring expander spacer end gap cannot be
measured. If the oil ring rail gap is excessive, re-
place all three piston rings.
Piston ring
Top ring
End gap (installed)
0.15–0.25 mm (0.0059–0.0098
in)
Limit
0.50 mm (0.0197 in)
2nd ring
End gap (installed)
0.40–0.50 mm (0.0157–0.0197
in)
Limit
0.75 mm (0.0295 in)
Oil ring
End gap (installed)
0.10–0.35 mm (0.0039–0.0138
in)
EAS24440

CHECKING THE PISTON PINS

The following procedure applies to both of the
piston 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.
Piston pin outside diameter
14.991–15.000 mm (0.5902–
0.5906 in)
Limit
14.971 mm (0.5894 in)
CYLINDER AND PISTONS
3. Measure:
• Piston pin bore diameter "b"
Out of specification → Replace the piston.
Piston pin bore inside diameter
15.002–15.013 mm (0.5906–
0.5911 in)
Limit
15.043 mm (0.5922 in)
4. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Out of specification → Replace the piston pin
and piston as a set.
• 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 (0.0001–0.0009
in)
EAS24470

INSTALLING THE PISTONS AND CYLINDER

The following procedure applies to all of the pis-
tons and cylinders.
1. Install:
• Top ring
• 2nd ring
• O-ring
5-29