ZEST BOLT Service Manual

Revotron 1.2T 65 H. Piston and Piston Rings : 1. Remove carbon deposits, if any, from the piston. 2. Clean piston and piston rings using appropriate cleansing agent. NOTE • The piston and piston rings can be reused if the bore taper and sphericity is within the specified limits. • Carefully examine the piston rings for cracks, scoring, ring groove/ clip groove wear, piston pin bore wear. • In case anyone piston is found to have any one of the above defects, replace the complete piston set. 3. Check for lateral clearance in piston ring groove. 4. Check for butt clearance in cylinder bore. 5. Check for piston pin dimensions. Details Specification (mm) Piston pin diameter 18.995/19.000 Piston pin length 54.0 Piston pin bore in piston 53.7 Height of piston 46.75 Piston to bore clearance 0.040 - 0.060 Maximum permissible difference in weights of piston with pin and rings 3 gms NOTE • Butt clearance of piston ring is measured in unworn portion of the cylinder bore. • Piston and piston rings of appropriate size should be used, if cylinder bores are re- bored. • If piston ring is found to be defective as started above, then complete ring set should be replaced. Piston and Cylinder Bore Sizes (Revotron 1.2T) Type Grade Cylinder Bore Dia. (mm) Piston Dia. (mm) Standard A 75.010/75 74.960/74.950 B 75.020/75.010 74.970/74.960 C 75.030/75.020 74.980/74.970 Piston Rings (Revotron 1.2T) Type of ring Ring Thickness (mm) Axial Clearance in Piston Groove (mm) Butt Clearance in Cylinder Bore (mm) 1 st Compression Ring 1.190/1.170 0.03/0.07 0.15/0.3 2 nd Compression Ring 1.990/1.970 0.02/0.06 0.30/0.50 3 rd Oil Control Ring 2.99/2.97 - 0.2/0.6