2001 Mercury Mariner 50-60HP Factory Service Manual, Page 264Get this manual
CYLINDER BLOCKCRANKCASE
PISTON RING END GAP CLEARANCE 1Measure piston ring end gap clearanceReplace piston ring if out of specification
aPush Piston Rings into Cylinder 0.8 in(20 mm) DeepPush in the Rings Using the PistonPiston Ring End Gap Top 2nd Oil 0.0060.012 in(0.150.30 mm) 0.0120.020 in(0.300.50 mm) 0.0080.028 in(0.200.70 mm)