1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 201Get this manual
7Finish installing the wrist pin through the connecting rod and the piston until the wrist pin contacts the installed retaining ringThis can be accomplished more easily if the piston is heated slightly, causing it to expandCheck to be sure none of the needle bearings have been disturbed and pushed out of the connecting rodInstall the remaining retaining ring 8Check piston with micrometer to determine whether piston
has been distorted during assemblyReplace the piston if variation in diameter at the bottom of the piston skirt is greater than 10 mm (0.004 in