Checking The Piston Ring Grooves; Checking The Piston Ring Side Clearance; Checking The Connecting Rod Big End Side Clearance - Yamaha F80B Service Manual

POWR
3. Check the piston ring end gap d at the
specified measuring point. Replace if out
of specification.
Piston ring end gap d:
Top ring:
0.15–0.30 mm
(0.0059–0.0118 in)
Second ring:
0.70–0.90 mm
(0.0276–0.0354 in)
Oil ring:
0.20–0.70 mm
(0.0079–0.0276 in)
Measuring point e: 20 mm (0.8 in)

Checking the piston ring grooves

1. Measure the
Replace the piston if out of specification.
5-43
Power unit
piston ring grooves.
a
b
c
S63P5720
Piston ring groove:
Top ring a:
1.23–1.25 mm (0.048–0.049 in)
Second ring b:
1.52–1.54 mm (0.060–0.061 in)
Oil ring c:
2.51–2.53 mm (0.099–0.100 in)
Checking the piston ring side
clearance
1. Measure the piston ring side clearance.
Replace the piston and piston rings as a
set if out of specification.
Piston ring side clearance:
Top ring a:
0.04–0.08 mm
(0.0016–0.0031 in)
Second ring b:
0.03–0.07 mm
(0.0012–0.0028 in)
Oil ring c:
0.03–0.15 mm
(0.0012–0.0059 in)
Checking the connecting rod big end
side clearance
1. Measure the connecting rod big end side
clearance a. Replace the connecting
rod or crankshaft or both if out of specifi-
cation.
a
b
c
S63P5730
6D93G11