KYMCO K-XCT 300i Owner's Manual page 202

3. Engine > Cylinders and Pistons
Measure the ring groove width and the ring-to-groove clearance with
feeler gauges.
Piston ring-to-groove clearance
Insert the top ring into the cylinder. Push the top ring in the cylinder about
an inch. Use the piston to push in the ring to keep it square with the
cylinder.
Item Standard mm
1st 0.015 - 0.055
2nd 0.015 - 0.055
3-58
K- XCT 300i