3. TROUBLESHOOTING
47
PISTON RING
Check with piston converting in the cylinder, and inserting feeler between piston skirt
bearing face and wall, then pull the feeler out, if feeling resistance and smoothly out, the
thickness of the feeler shall be considered as piston-cylinder clearance.
Standard Service
Limit
0.015-0.02mm 0.12mm
d) Piston ring side clearance
Check with placing each ring into each-self groove. The piston
ring should be freely turned without loosening and sticking.
Then measure with inserting feeler into clearance of the ring and
upper and lower face.
Standard Service
Limit
0.030-0.060mm 0.15mm
e) Piston ring closed clearance
Flatly place the piston into the cylinder with pushing the piston head to working position.
Measure the opening clearance with feeler, that
clearance not too big or not to small, too big can
result in cylinder sealing performance poor
while too small can result in piston expanded
from heating and blocked in the cylinder, thus
causing piston broken and “sticking”. If opening
clearance is too small, file the opening with fine
flat file. Often check in the cylinder when filing
until the proper clearance is got.
Standard
Service
Limit
Top Ring/Second Ring
0.2-0.4mm
1.0mm
Oil Ring
0.2-0.7mm
1.0mm
