1991 Johnson/Evinrude Models "EI" 40 thru 55 Service Manual, Page 90Get this manual
Assembly When assembling the fuel piston, always install new washer and stem in addition to other new parts requiredBe sure to lightly tighten stem with fingers; never use pliers 'sl Lubricate stem with Evinrude or Johnson Outboard Lubricant
and slide it into hole in center of intermediate housing'7l lnstall new washer on air motor piston screwThen, thread l.J air motor piston onto stem with clockwise rotationPush poppet valve in (toward the stem) to hold the screw in place while turningTighten 14 turn past point of contact