Checking The Piston Pins; Installing The Piston And Cylinder - Yamaha TMAX 2020 Service Manual

G089003
a. Bottom of cylinder
b. Upper of cylinder
EAS30293

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
16.995–17.000 mm
(0.6691–0.6693 in)
Limit
16.975 mm (0.6683 in)
G089004
3. Measure:
• Piston pin bore inside diameter "b"
Out of specification  Replace the piston.
Piston pin bore inside diameter
17.002–17.013 mm
(0.6694–0.6698 in)
Limit
17.043 mm (0.6710 in)
a
b
G089005
4. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Piston-pin-to-piston-pin-bore clearance =
Piston pin bore inside diameter -
Piston pin outside diameter
EAS30294

INSTALLING THE PISTON AND CYLINDER

The following procedure applies to all of the pis-
tons and cylinders.
1. Install:
• Oil ring expander "1"
• Lower oil ring rail "2"
• Upper oil ring rail "3"
• 2nd ring "4"
• Top ring "5"
TIP
Be sure to install the top and 2nd rings so that
the manufacturer marks or numbers "a" face up.
G089011
2. Install:
• Piston "1"
• Piston pin "2"
• Piston pin clip "3"
5-33
CYLINDER AND PISTONS
b
Out of specification  Replace the piston pin
and piston as a set.
Piston-pin-to-piston-pin-bore
clearance
0.002–0.018 mm (0.0001–0.0007
in)
(into the piston)
New