Kubota M6800S Workshop Manual page 138

M6800 · M6800S · M8200 · M9000, WSM
Clearance between Piston Ring and Groove
1. Remove carbon from the ring grooves.
2. Measure the clearance between the ring and the groove with a
feeler gauge or depth gauge.
3. If the clearance exceeds allowable limit, replace the ring since
compression leak and oil shortage result.
4. If the clearance still exceeds the allowable limit after replacing the
ring, replace the piston.
Compression ring 2
Factory spec.
Oil ring
Compression ring 2
Allowable limit
Oil ring
Factory specification : a
(A) Top Ring (Key Store Type)
Piston Ring Gap
1. Insert the piston ring into the lower part of the liner (the least worn
out part) with the piston.
2. Measure the ring gap with a feeler gauge.
3. If the gap exceeds the allowable limit, replace the piston ring.
Factory spec.
Compression ring 1, 2
Allowable limit
Factory spec.
Oil ring
Allowable limit
Connecting Rod Alignment
NOTE
• Since the I.D. of the connecting rod small end bushing is the
basis of this check, check the bushing for wear beforehand.
1. Remove the piston pin in the connecting rod.
2. Install the piston pin in the connecting rod.
3. Install the connecting rod on the connecting rod alignment tool
(Code No. 07909-31661).
4. Put a gauge over the piston pin, and move it against the face
plate.
5. If the gauge does not fit squarely against the face plate, measure
the space between the pin of the gauge and the face plate.
6. If the measurement exceeds the allowable limit, replace the
connecting rod.
Connecting rod
Allowable limit
alignment
1-S53
ENGINE
0.093 to 0.120 mm
0.0037 to 0.0047 in.
0.020 to 0.060 mm
0.0008 to 0.0023 in.
0.20 mm
0.0079 in.
0.15 mm
0.0059 in.
More than 0.2 mm
0.079 in.
(B) 2nd, Oil Ring
W1066183
0.30 to 0.45 mm
0.0118 to 0.0177 in.
1.25 mm
0.0492 in.
0.25 to 0.45 mm
0.0098 to 0.0177 in.
1.25 mm
0.0492 in.
W1066430
0.05 mm
0.0020 in.
W1066581
KiSC issued 03, 2008 A