8. CYLINDER/PISTON MXU 300/250 Remove the piston rings and insert each piston ring into the cylinder bottom. Use the piston head to push each piston ring into the cylinder. Measure the piston ring end gap. Service Limit (replace if over): Top: 0.5 mm (0.02 in) 2nd: 0.65 mm (0.026 in) Oil ring: 0.9 mm (0.036 in) Measure the piston pin hole I.D. Service Limit (replace if over): 17.04 mm (0.6816 in) Measure the piston pin O.D. Service Limit (replace if below): 16.96 mm (0.6784 in) 8-6