Westerbeke 3.0KW BPMG-60HZ Service Manual page 30

INSPECTION AND MEASUREMENTS
Measurement with thickness gauge
• Clearance between piston ring and ring groove
Standard value Out of the limit to use
Top
0.04 - 0.08 mm If 0.10 mm (0.004 in) or
0.0016 - 0.0031 In more,
tt
needs replacement.
0.03 - 0.07 mm If 0.09 mm (0.0035 in) or
Second 0.0012 - 0.0028 in more, it needs replacement.
Oil
0.01 - 0.18 mm If 0.21 mm (0.0083 in) or
0.0004 - 0.0071 In more, it needs replacement.
• Piston ring end gap
Standard value Out of the limit to use
Top
0.15 - 0:35 mm
If 0.5 mm (0.020 in) or
0.006 - 0.014 In
more,
tt
needs replacement.
Second
0.30 - 0.50 mm
If 0.7 mm (0.028 in) or
0.012 - 0.020 in
more, It needs replacement.
Oil
0.20 - 0.70 mm
0.008 - 0.028 in
Note:
• Set the piston ring by pressing it in the piston
crown side.
• To be replaced with a new oil ring when replacing
with new top and/or second rings.
• Side clearance at big end of connecting rod
Standard value
0.1 - 0.25mm
0.004 - 0.D1 in
Out of the limit to use
If 0.6 mm (0.024 in) or more,
it needs replacement.
• Side clearance of crankshaft
Standard value
0.1 - 0.3 mm
0.004 - 0.012 in
Out of the limit to use
0.6 mm (0.024 in) more
If the side clearance is out of the limit, measure
length of the crankcase (cylinder side) and the
crankshaft and replace crankshaft and/or
cylinder-crankcase ass'y.
Standard value
Crankshaft length
126.8 - 126.9 mm
4.992 - 4.996 in
Crankcase length
127.0 - 127.1 mm
5.000 - 5.004 in
Engines
& Generators
23