1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 143Get this manual
IMPORTANT: On some engines, BOTH the piston rod and rod cap bolt holes are threadedThe rod cap and rod must be aligned and held tight together when threading in rod cap boltsCheck mating surfaces to be sure that they are tight together after bolt enters the threads in the piston rod16Remove main bearing sealing ringsper center main journal 18Use piston ring expander (91-24697) to remove piston ringsAlways install new piston rings
NOTE: Cylinders must be honed in order for new rings to seat properly51081Piston Ring Expander (PN 91-24697)Piston Rings
CAUTION
Eye protection MUST BE worn while removing piston pin lockrings from piston51083