9. CYLINDER/PISTON
9-2
Precautions in Operation
General Information
y Both cylinder and piston service cannot be carried out when engine mounted on frame.
Specification Unit:mm
Item Standard Limit
ID 57.400~57.415 57.416
Cylinder
Bend - 0.050
Top ring 0.015~0.050 0.090
Clearance between piston
rings
2
nd
ring 0.015~0.050 0.090
Top ring 0.150~0.300 0.500
2
nd
ring 0.300~0.450 0.650
Ring-end gap
Oil ring side rail 0.200~0.700 -
OD of piston 57.400~57.405 57.390
Clearance between piston and cylinder 0.010~0.040 0.100
Piston/
Piston ring
ID of piston pin boss 15.002~15.008 15.040
OD of piston pin 14.960~15.000 14.930
Clearance between piston and piston pin 0.002~0.014 0.020
ID of connecting rod small-end 15.016~15.034 15.060
Item Standard Limit
Cylinder ID 57.395~57.415 57.416
Piston OD of piston 57.385 ~57.405 57.300
Trouble Diagnosis
Low or Unstable Compression Pressure
y Cylinder or piston ring worn out
Knock or Noise
y Cylinder or piston ring worn out
y Carbon deposits on cylinder head top-side
y Piston pin hole and piston pin wear out
Smoking in Exhaust Pipe
y Piston or piston ring worn out
y Piston ring installation improperly
y Cylinder or piston damage
Engine Overheat
y Carbon deposits on cylinder head top side
y Cooling pipe clogged or not enough in coolant
flow