1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 235Get this manual
Crankshaft and Seal Rings
Check seal rings for wearIf the seal ring is worn the sides will be noticeably grooved by the crankshaftReplace all worn or broken seal rings1When installing seal ring, first spread the end gap just enough to permit slipping it over the nearest crankshaft journalThen, using ring expanding pliers, install the ring in the groove2Following installation, lubricate each ring and groove liberally with oil
Piston Rings
I nstall the piston rings on each pistonSpread each ring with ring expander just enough to slip it over the head of the piston and down into placeBe sure the rings fit freely in the piston ring groovesThe ring grooves are pinned to secure the position of the rings, primarily to prevent ends of the rings from catching on the edges of the ports in the cylinders, but also to assure staggering of the ring gapsPlace the pressure back ring into the upper ring groove