Checking The Piston Ring Side Clearance; Checking The Piston Pin Boss Bore; Checking The Piston Pin Diameter; Checking The Connecting Rod Small End Inside Diameter And Big End Inside Diameter - Yamaha F30A Service Manual

POWR
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:
0.02–0.06 mm
(0.0008–0.0024 in)
2nd ring b:
0.02–0.06 mm
(0.0008–0.0024 in)
Oil ring c:
0.04–0.18 mm
(0.0016–0.0071 in)

Checking the piston pin boss bore

1. Measure the piston pin boss bore.
Replace the piston if out of specification.
Piston pin boss bore:
15.974–15.985 mm
(0.6289–0.6293 in)

Checking the piston pin diameter

1. Measure the
Replace if out of specification.
5-45
Power unit
a
b
c
S67C5131
S6AU5137
piston pin diameter.
Piston pin diameter:
15.965–15.970 mm
(0.6285–0.6287 in)
Checking the connecting rod small
end inside diameter and big end
inside diameter
1. Tighten the connecting rod cap bolts to
the specified torques in 2 stages.
Connecting rod cap bolt:
1st: 6 N·m (0.6 kgf·m, 4.4 ft·lb)
2nd: 17 N·m (1.7 kgf·m, 12.5 ft·lb)
2. Measure the connecting rod small end
inside diameter a and big end inside
diameter b. Replace the connecting rod
if out of specification.
b
Connecting rod small end inside
diameter a:
15.985–15.998 mm
(0.6293–0.6298 in)
Connecting rod big end inside
diameter b:
36.000–36.024 mm
(1.4173–1.4183 in)
a
S67C5134
67C3K11