Mercury Mariner Service Manual 6, 8, 9.9 210CC Sailpower, Page 82Get this manual
gSupport bottom of piston and hold piston pin tool (a) up against piston pinhDrive piston pin (b) into piston pin bore (with soft face mallet) until pin is flush with piston 8Install new piston pin lockrings (a) into grooves in both ends of piston pin bore
IMPORTANT: Retaining ring tapper away from lower crankshaft ball bearingMove piston pin tool (a) to top of piston pin bore and center piston pin into piston