1975 Johnson 4HP 4R75, 4W75 Outboards Service Manual, Page 43Get this manual
EXHAUST
Figure 5-15Checking Ring Gap
Figure 5-17Correct Piston Position bApply coat of oil to wrist pin, making sure surface is cleanPlace drop or two of oil in each pin hole in the pistoncInsert wrist pin through slip fit side of pistonOil wrist pin bearing in connecting rodPlace connecting rod in pOSition, then proceed to install the wrist pinThis can be accomplished more easily if the piston is heated slightly, causing it to expand