Inspection

PISTON AND CONNECTING ROD INSPECTION

PISTON RING INSPECTION

1. Check the piston ring for damage, excessive wear, and breakage. Replace if defects are evident. If the piston has been replaced with a new one, the piston rings must also be replaced with new ones.





2. Check for clearance between the piston ring and ring groove. If the limit is exceeded, replace the ring or piston, or both.

Standard value:
Number 1: 0.04 - 0.08 mm (0.0016 - 0.0031 inch)
Number 2: 0.03 - 0.07 mm (0.0012 - 0.0027 inch)
Limit: 0.1 mm (0.004 inch)






3. Insert the piston ring into the cylinder bore. Force the ring down with a piston, the piston crown being in contact with the ring, to correctly position it at right angles to the cylinder wall. Then, measure the end gap with a feeler gauge.
If the ring gap is excessive, replace the piston ring.

Standard value:
Number 1: 0.18 - 0.33 mm (0.008 - 0.012 inch)
Number 2: 0.28 - 0.48 mm (0.012 - 0.018 inch)
Oil: 0.10 - 0.60 mm (0.004 - 0.023 inch)

Limit:
Number 1, Number 2: 0.8 mm (0.03 inch)
Oil: 1.0 mm (0.04 inch)


CRANKSHAFT PIN OIL CLEARANCE [PLASTIGAGE METHOD]

The crankshaft oil clearance can be measured easily by using plastigage method, as follows:

1. Remove oil from the crankshaft pin and the bearing inner surface.





2. Cut plastigage to the same length as the width of the bearing and place it on the pin in parallel with its axis.
3. Install the connecting rod cap carefully and tighten the nuts to the specified torque.
4. Carefully remove the connecting rod cap.





5. Measure the width of the smashed plastigage at its widest section by using a scale printed on the plastigage bag.

Standard value: 0.012 - 0.039 mm (0.0005 - 0.0015 inch)
Limit: 0.1 mm (0.004 inch)