Piston Ring Inspection; Crankshaft Inspection - Yamaha EF2800i Service Manual

PISTON, CONNECTING ROD, CRANKSHAFT AND
CRANKCASE

PISTON RING INSPECTION

1. Measure:
• Piston ring end gap
Out of specification → Replace.
NOTE:
Insert the piston ring 1 into the cylinder, and
push it approximately 5 mm (0.2 in) into the cylin-
der. Push in the ring with the piston crown so that
the ring is at right angles to the cylinder bore.
SVU3650
Top ring
2nd ring
Oil ring
2. Measure:
• Piston ring side clearance
Out of specification → Replace.
Use a thickness gauge 1.
Top ring
SVU3660
2nd ring
NOTE:
• Clean carbon deposits from the piston ring
grooves and rings before measuring the
side clearance.
• Measure the side clearance at several portions.

CRANKSHAFT INSPECTION

1. Measure:
• Crankshaft runout limit
Use a dial gauge.
Out of specification → Replace.
Runout limit:
SVU3670
3-34
ENG
Ring end gap
0.2 ~ 0.4 mm
(0.008 ~ 0.016 in)
0.2 ~ 0.4 mm
(0.008 ~ 0.016 in)
0.2 ~ 0.4 mm
(0.008 ~ 0.016 in)
Piston ring side
clearance
0.04 ~ 0.08 mm
(0.0016 ~
0.0031 in)
0.02 ~ 0.06 mm
(0.0008 ~
0.0024 in)
0.04 mm (0.0016 in)
Wear limit
0.9 mm
(0.0354 in)
0.9 mm
(0.0354 in)
0.9 mm
(0.0354 in)
Wear limit
0.1 mm
(0.0039 in)