Service Manual

8-19
Table of Contents
Inspection
Twin Cylinder Engine Service Manual
February 2017 - Digital Edition
ENGINE INSPECTION AND RECONDITIONING
Lower End Inspection and Reconditioning (Cont.)
Pistons (Cont.)
8. Piston Rings inspect and measure:
Inspect each for surface wear, broken, pitting or scratches. Measure and compare each ring to specifications
(Figure 19).
Ring Thickness
Ring Standard Service Limit
Width (Top) 0.038-0.039 in. (0.97-0.99 mm) 0.0354 in. (0.90 mm)
Width (Middle) 0.046-0.047 in. (1.17-1.19 mm) 0.0433 in. (1.10 mm)
Width (Oil Ring) 0.110-126 in. (1.65-1.85 mm) 0.1063 in. (1.60 mm)
9. Piston ring end gap measurement:
Insert into the matching cylinder, use a piston dome to push ring evenly into the cylinder bore about one inch.
Check the end gap of top and middle rings for each piston.
Piston ring end gap measurement
Standard (Height) 0.0078-0.0157 in.
Service Limit 0.0177 in.
10. Replace ring set if any of the three rings are out of specification.
Figure 19