1984-1986 Mercury Force 4HP Outboards Service Manual, Page 48Get this manual
2i nstall piston rings on piston using ring xpander(Special Tooi NoT 8926) TOP OF CYLINDER OPEN END OF PtSTON PIN
CAUTION
i nstall piston rings with bevel on inner diameter positioned up toward top of piston Figure
TOP OF PI STON
MATCH MARKS
"SLOT UP Agur28Position of Rod and PistonCPlace rin compressor (Special Tool NoT 2997) over pistonCompressor should rest on cyl inder sleeveTap top edges of compressor making it uniform
OTighten compressor until piston rings are compressed sufficiently to enter bore Push piston Into bore wi th thumb pressu re
CAUTION
Agur27Installing Piston RingsInsufficient tightening of compressor can result in damage to piston Figure 29COMPRESSOR NOT PROPERLY TI GHTENED