1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 199Get this manual
o COB1252 COB1269
22Remove the rings from the pistons by prying the ends loose enough to grip them with pliers and then breaking them away from the pistonDO NOT try to save the ringsInstall complete set of new rings on every powerhead service job23If necessary to remove piston from connecting rod, remove wrist pin retaining ring, using OMC Special Tool PIN 325937 (Wrist Pin Retaining Ring Remover)
INotel On some models:
One side of piston is marked "L" on insideWhen wrist pin is to be removed, "L" side of piston must be up and arbor pressing tool must be applied to loose sideAlways press from loose side to tight side, being careful not to distort piston24Drive wrist pin through piston using OMC Special Tool PIN 326573 (Piston Cradle) and PIN 326356 (Wrist Pin Pressing Tool)Be careful not to lose any of the 28 needle bearings or the two wrist pin washersIf the bearings are worn, replace the bearings on reassembly25Refer to Cleaning, Inspection and Repair at beginning of this sectionCOB1301