Piston Ring Inspection - Yamaha EF2000iS Manuel D'atelier

PISTON, CONNECTING ROD, CRANKSHAFT AND
1

PISTON RING INSPECTION

a
TIP
Insert the piston ring 1 into the cylinder, and
push it approximately a 5 mm (0.2 in) into the
cylinder. Push the ring with the piston crown so
that the ring is at angles to the cylinder bore.
TIP
9 Clean carbon deposits from the piston ring
9 Measure the side clearance at several por-
3-39
CRANKCASE
1. Measure:
9 Piston ring end gap
Out of specification → Replace.
Ring end gap
0.20 – 0.40 mm
Top ring
(0.008 – 0.016 in)
0.20 – 0.40 mm
2nd ring
(0.008 – 0.016 in)
0.20 – 0.70 mm
Oil ring
(0.008 – 0.028 in)
Out of specifications → Replace the
piston and piston ring as a set.
2. Measure:
9 Piston side clearance
Out of specification → Replace.
Use a thickness gauge 1.
grooves and rings before measuring the
side clearance.
tions.
Piston ring side
clearance
0.04 – 0.08 mm
Top ring (0.0016 –
0.0031 in)
0.02 – 0.06 mm
2nd ring (0.0008 –
0.0023 in)
ENG
Wear limit
0.6 mm
(0.0236 in)
0.6 mm
(0.0236 in)
0.9 mm
(0.0354 in)
Wear limit
0.12 mm
(0.0236 in)
0.1 mm
(0.0039 in)