Cleaning and Inspection
INSPECTIONPiston Ring
1. Check the clearance between the piston ring and ring groove. If the limit is exceeded, replace the ring or piston, or both.
Standard value: No. 1: 0.03-0.07 mm (0.0012-0.0028 inch) / No. 2: 0.02-0.06 mm (0.0008-0.0024 inch)
Limit: 0.1 mm (0.004 inch)
2. Insert a piston ring into the cylinder bore. Force it down with a piston, its crown being in contact with the ring, to correctly position it at right angle to the cylinder wall. Then, measure the end gap with a feeler gauge. If the end gap is excessive, replace the piston ring.
Standard value: No. 1: 0.25-0.40 mm (0.0098-0.0157 inch) / No. 2: 0.40-0.55 mm (0.0157-0.0217 inch) / Oil: 0.15-0.50 mm (0.0059-0.0197 inch)
Limit: No. 1: 0.8 mm (0.031 inch) / No. 2: 0.8 mm (0.031 inch) / Oil: 1.0 mm (0.039 inch)
Crankshaft Pin Oil Clearance (Plastigage Method)
The crankshaft oil clearance can be measured easily by using a Plastigage, as follows:
1. Remove oil and grease and any other foreign material from the crankshaft pin and the bearing inner surface.
2. Install the crankshaft.
3. Cut the Plastigage to the same length as the width of the bearing and place it on the pin in parallel with its axis.
4. Gently place the crankshaft bearing cap over it and tighten the bolts to the specified torque.
5. Remove the bolts and gently remove the crankshaft bearing cap.
6. Measure the width of the smashed Plastigage at its widest section by using a scale printed on the Plastigage bag.
Standard value: 0.02-0.05 mm (0.0008-0.0020 inch)
Limit: 0.1 mm (0.004 inch)