2006-2010 Suzuki DF150 / DF175 4-Stroke Outboards Service Manual, Page 276Get this manual
POWER UNIT
PISTON Inspect piston for faults, cracks or other damageDamaged or faulty piston(s) should be replaced Piston ring to groove clearance Before checking, piston grooves must be clean, dry and free of carbonFit piston ring into piston groove, and measure clearance between ring and ring groove using thickness gauge$ 09900-20803: Thickness gauge Piston ring to groove clearance Standard: 1st 0.030 0.070 mm (0.0012 0.0028 in) 2nd 0.020 0.060 mm (0.0008 0.0024 in) Service limit: 1st 0.12 mm (0.0047 in) 2nd 0.10 mm (0.0039 in) If measurement exceeds service limit, replace piston andor piston ringPiston ring groove width Standard: 1st 1.22 1.24 mm (0.0480 0.0488 in) 2nd 1.21 1.23 mm (0.0476 0.0484 in) Oil 2.51 2.53 mm (0.0988 0.0996 in) Piston ring thickness Standard: 1st 1.17 1.19 mm (0.0461 0.0469 in) 2nd 1.17 1.19 mm (0.0461 0.0469 in) PISTON RING Piston ring end gap Measure piston ring end gap with piston ring in the lowest position of cylinder bore$ 09900-20803: Thickness gauge Piston ring end gap Standard: 1st 0.20 0.30 mm (0.0079 0.0118 in) 2nd 0.30 0.45 mm (0.0118 0.0177 in) Service limit: 1st 0.70 mm (0.0276 in) 2nd 1.00 mm (0.0394 in) If measurement exceeds service limit, replace piston ring