1988-1992 Mercury Force 5HP Outboards Service Manual, Page 174Get this manual
6 Install assembled piston into bore Coat piston and cylinder bore with oilSet assembled piston in bore, open end of piston pin facing top of cylinderTOP OF CYLINDER OPENENDOF PISTON PIN
NOTE: Check that staking pins are in ring gaps and rings are properly positioned in their grooves
IMPORTANT
Damage to piston andor ring may result from imperfect alignment of ring gap and staking pin
Place ring compressor (Special Tool NoT-2997) over pistonCompressor should rest on cylinder sleeveTap top edges of compressor, making it uniformTighten compressor until piston rings are compressed sufficiently to enter borePush piston into bore with thumb pressure