2003 Johnson ST 55 HP WRL 2 Stroke Commercial Service Manual, PN 5005483, Page 61Get this manual
MAINTENANCE SUBMERGED ENGINES IMPORTANT: DO NOT hold constant throttle settingChange outboard speed every 15 minutesWith easy planing boats, use full throttle to quickly accelerate boat onto planeImmediately reduce throttle to one-half as soon as boat is on planeBE SURE boat remains on plane at this throttle settingSecond HourUse FULL throttle to accelerate boat onto plane, then reduce throttle setting to three-quartersBE SURE boat remains on plane at this throttle settingAt intervals, apply full throttle for periods of one to two minutes, returning to three-quarter throttle for cooling periodChange outboard speed every 15 minutesNext Eight HoursAvoid continuous full throttle operation for extended periodsChange outboard speed every 15 minutes SUBMERGED ENGINES
If the engine has been under water, have it serviced immediately upon recoveryAfter submersion, all boat and engine electrical, fuel, and oiling systems must be inspected for signs of water intrusionOnly dealers should perform this service
IMPORTANT: If outboard cannot be started or serviced immediately, it should be resubmerged in fresh water to avoid exposure to the atmosphere