Kubota EA330-E4 Series - Page 117

ENGINE
EA330-E4, WSM
1-S52
Piston Ring Gap
1. Insert the piston ring into the lower part of the liner (Measuring
points are shown in the figure) with a piston ring compressor
and the piston.
2. Measure the ring gap with a feeler gauge.
3. If the gap exceeds the allowable limit, replace the piston ring.
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Clearance between Piston Ring and Ring Groove
1. Clean the rings and the ring grooves, and install each ring into
its groove.
2. Measure the clearance between the ring and the groove with a
feeler gauge.
3. If the clearance exceeds the allowable limit, replace the piston
ring.
4. If the clearance still exceeds the allowable limit with new ring,
replace the piston.
NOTE
• As the top ring is a Keystone type, it cannot be measured
by this method.
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Ring gap
Factory
specifica-
tion
Top r in g
Second
ring
0.30 to 0.45 mm
0.012 to 0.017 in.
Oil ring
0.25 to 0.40 mm
0.0099 to 0.015 in.
Allowable limit
1.2 mm
0.047 in.
(a) Approx. 90 mm (3.5 in.)
Clearance between
piston ring and ring
groove
Factory
specifica-
tion
Top ring Keystone ring
Second
ring
0.0850 to 0.112 mm
0.00335 to 0.00440 in.
Oil ring
0.020 to 0.055 mm
0.00079 to 0.0021 in.
Allowable
limit
Second
ring
0.2 mm
0.008 in.
Oil ring
0.15 mm
0.0059 in.
KiSC issued 05, 2015 A