KYMCO XCITING S 400 Manual page 133

3. Engine > Cylinders and Pistons
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.
Measure the ring gap with a feeler gauge. Repeat this procedure with
second ring and the oil side rails.
Ring end gap
Item
Top
Second
Oil side rail
Standard mm
0.10 - 0.25
0.10 - 0.25
0.2 - 0.7
3‐55
XCITING 400i