2003 Johnson ST 55 HP WRL 2 Stroke Commercial Service Manual, PN 5005483, Page 110Get this manual
FUEL SYSTEM PRIMER PUMP Insert plunger shaft and end cap into primer pump housingReinstall retainer clipPrimer should pump approximately 10 cc of alcohol in ten strokesIf pump fails to pump alcohol, disassemble and check for missing, cut, or split O-rings or damaged check valvesConnect inlet hose from the carburetor fuel bowl to the large nipple on the bottom of the pump housingConnect the primer hose from the fittings at the top of the carburetors to the smaller nipple on the top of the pump housingPlace the pump in position in the lower motor cover and secure with mounting screwsTo bench test the primer pump after assembly, connect in(12.7 cm) piece of hose to the large nipple and place the other end of hose in container of alcoholPlace hose on the small nipple and place other end of hose to drain into graduated containerHold primer pump in horizontal position as it would be installed on the engineMove plunger back and forth ten timesConnect knob assembly to pump and tighten retaining screw