Suzuki DF25/DF30 Four Stroke Service Manual, Page 161Get this manual
7-44 POWER UNIT PISTON RING Piston ring end gap Measure piston ring end gap with piston ring in the lowest position of cylinder bore09900-20803: Thickness gauge Piston ring end gap Standard: 1st0.12 0.27 mm (0.005 0.011 in 2nd0.35 0.50 mm (0.014 0.020 in Service limit1st0.70 mm (0.028 in 2nd1.00 mm (0.039 in If measurement exceeds service limit, replace position ringPiston ring