2001 Edition Yamaha F225A and LF225A Outboards Service Manual, Page 146Get this manual
Power unit
Checking the piston ring side clearance
1Measure the piston ring side clearanceReplace the piston and piston rings as set if out of specification
Piston ring end gap d: Top ring: 0.150.30 mm (0.00590.0118 in) Second ring: 0.300.45 mm (0.01180.0177 in) Oil ring: 0.150.60 mm (0.00590.0236 in) Measuring point e: 20 mm (0.8 in)
Piston ring side clearance: Top ring a: 0.040.08 mm (0.00160.0031 in) Second ring b: 0.030.07 mm (0.00120.0027 in) Oil ring c: 0.040.13 mm (0.00160.0051 in)