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defects, piston top for burn and cracks. If damaged, replace.
Clean the carbon deposit
Clean the deposit round the piston top and cylinder neck before checking, first soak the
carbon deposit with kerosene, and then clean with meter scraper or metal brush.
a)
Piston skirt O.D
Measure the piston skirt O.D with outside micrometer, if out of
the service limit, replace it.
b) Piston pin bore to piston clearance
Separately measure the piston pin bore I.D and O.D with inside micrometer and outside
micrometer. Then calculate clearance by measuring results.
Standard
Service Limit
0.002-0.014mm
0.08mm
c) Piston-cylinder clearance
Difference between cylinder maximum diameter and piston skirt should be considered as
piston-cylinder clearance.
This clearance must be checked before and after repairing.
Standard
Service Limit
67.985mm
67.845mm
