7. CYLINDER HEAD/CYLINDER/PISTON ATV 50 PISTON RING INSPECTION Measure each piston ring end gap. Service Limits: Top/Second: 0.4 mm (0.016 in) replace if over Set each piston ring squarely into the cylinder using the piston and measure the end gap. Piston Pin CONNECTING ROD SMALL END INSPECTION Install the piston pin and bearing in the connecting rod small end and check for excessive play. Measure the connecting road small end I.D. Service Limit: 17.03 mm (0.6812 in) replace if over Bearing PISTON/CYLINDER INSTALLATION Piston First install the expander in the second ring Top Ring (1st Ring) groove. Then install the top and second rings in their respective ring grooves. The piston rings should be pressed into the grooves with even force. After installation, check and make sure that Second Ring each ring is flush with the piston at several points around the ring. Expander A ring that will not compress means that the ring groove has carbon deposits in it and should be cleaned. 7-9