1999-2004 Suzuki King Quad LT-300 300F ATV Factory Service Manual, Page 77Get this manual
PISTON RING FREE END GAP AND PISTON RING END
GAP Measure the piston ring free end gap using vernier calipersNext, fit the piston ring squarely into the cylinder and measure the piston ring end gap with thickness gaugeIf any of the measurements exceed the service limit, replace the piston ring with new one
Moll 09900-20102: Vernier calipers
Service Limit Piston ring free end gap (1 st): 6.6 mm (0.26 in) (2nd): 6.8 mm (0.27 in)
.Moll 09900-20803: Thickness gauge
Service Limit Piston ring end gap (1 st): 0.50 mm (0.020 in) (2nd): 0.70 mm (0.028 in)