2006-2009 Suzuki LT-R450 Service Manual, Page 88Get this manual
Piston ring thickness Standard: 1st: 0.710.76 mm (0.02800.0299 in) 1.08 -1.10 mm (0.04250.0433 in) 2nd: 0.770.79 mm (0.03030.0311 in)
PISTON RING END GAP Fit the piston ring squarely into the cylinder and measure the piston ring end gap using the thickness gaugeIf any of the measurements exceeds the service limit, replace the piston ring with new one_ Piston ring end gap: Service Limit: 1st: 0.50 mm (0.020 in) 2nd: 0.50 mm (0.020 in)