1985 Mercury Outboard V-300 V-3.4L Shop Service Manual, Page 20Get this manual
FOLLOWING COMPLETE SUBMERSION S ubmerged ngi ne Ircatme n! is div ided inl 03 distinc problem areasThe most ritica is subme rsion in sa lt wat er: the second is submersion while runningweedsetcDO NOT attempt to start engine if sand has ent ered powerheadas power head will be severely dam aged Disassemble powerhead if necessa ry 10 clean compo nent s4Remove spark plugs and gel as much wat er as possi ble out of power headMost water can be eliminated by placing ngin in hori zontal position (with spark plug holes down) and rOlaling flywh eel5Po ur alcohol into carburetor Ihroat (alcohol will absorb wa ter)Again rotate fl ywheel6 ur engine over and pour alcohol in to spark plug open ings and again rotate fl y",heei7Turn ngine over (place spark plug openi ng down) and pour engine oil in to throa of carburetors while rotati ng fl ywheel to distribute oil throughout crankcase8 Aga in tllrn engine over and pour approximate ly ne tea spoon of ngine oil in to each spark plug open ingAgain ro tate fl ywheel to distribu te oil in cylinders9 Remove and clean carbu retors and fuel pump assembl y10Reinstall spark plugscarburelors and fu el pumpIIAtt empt to start engineusing fresh fuel sourceIf engin start sit should be rUIl for at leas one ho ur to eliminate an water in engine12I engi ne fa ils to slart determi ne cause (fu elelectrical or mec hanical)00 NOT allow engine to remain idle for mo re than hoursas serious interna damage wi ll occurI unable to start engi ne in hi period isassemble ngine and clean all pariS and apply oil as soon as possible