Yamaha WaveRunner - Cylinder and Piston Inspection

5-93
E
POWR
CONNECTING RODS AND PISTONS
Cylinder and piston inspection
The following procedure applies to all of the
cylinders and pistons.
1. Check:
• Piston wall
• Cylinder wall
Vertical scratches
→
Replace the cylin-
der, and the piston and piston rings as a
set.
2. Measure:
• Piston-to-cylinder clearance
Measurement steps:
• Measure cylinder bore “C” with the cylin-
der bore gauge.
Cylinder bore “C”
76.000–76.015 mm
(2.9921–2.9927 in)
Taper limit “T” 0.08 mm (0.003 in)
Out of round “R” 0.05 mm (0.002 in)
“C” = maximum of D
1
–D
6
“T” = maximum of D
1
–D
5
(direction
d
)
and D
2
–D
6
(direction
e
)
“R” = maximum of D
2
–D
1
(measuring
point
a
) and D
6
–D
5
(measuring point
c
)
• If out of specification, replace the cylin-
der, and the piston and piston rings as a
set.
• Measure piston skirt diameter “P” with the
micrometer.
a
5 mm (0.2 in) from the bottom edge of the
piston
Piston size “P”
Standard
75.895–75.910 mm
(2.9880–2.9986 in)
D1D2
D3D4
D5D6
d
e
a
b
c