7. CYLINDER HEAD/CYLINDER/PISTON ATV 50 CYLINDER/PISTON INSPECTION Check the cylinder and piston for wear or damage. Clean carbon deposits from the exhaust port area. Be careful not to damage the cylinder inside wall. Measure the cylinder bore at three levels of A, B and C in both X and Y directions. Avoid the port area. Take the maximum figure measured to determine the cylinder bore. Service Limit: 39.05 mm (1.56 in) replace if over Top Middle Bottom Inspect the top of the cylinder for warpage. Service Limit: 0.1 mm (0.004 in) replace if over 7-7