wsm M7040 - Page 206

ENGINE
M6040, M7040, WSM
1-S74
Piston Ring Gap
1. Insert the piston ring into the lower part of the liner (the least
worn part).
2. Measure the ring gap with a feeler gauge.
3. If the gap exceeds the allowable limit, replace the piston ring.
9Y1210143ENS0118US0
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, check the new ring.
4. If clearance still exceeds the allowable limit after replacing the
ring, replace the piston.
9Y1210143ENS0119US0
Top ring
Factory specification
0.25 to 0.40 mm
0.0098 to 0.0157 in.
Allowable limit
1.25 mm
0.0492 in.
Second ring
Factory specification
0.30 to 0.45 mm
0.0118 to 0.0177 in.
Allowable limit
1.25 mm
0.0492 in.
Oil ring
Factory specification
0.25 to 0.45 mm
0.0098 to 0.0177 in.
Allowable limit
1.25 mm
0.0492 in.
Factory specification
Top r in g
0.050 to 0.090 mm
0.0020 to 0.0035 in.
Second ring
0.090 to 0.120 mm
0.0035 to 0.0047 in.
Oil ring
0.020 to 0.060 mm
0.0008 to 0.0023 in.
Allowable limit
Top r in g
0.15 mm
0.0059 in.
Second ring
0.20 mm
0.0079 in.
Oil ring
0.15 mm
0.0059 in.
KiSC issued 07, 2012 A