Re: Sea king year ??
It is a 1956 12hp. Motor was made by Gale Products Division of OMC and shares many but not all parts with it's Johnson and Evinrude cousins. Yes, the J/E single line hose connector will work.
Fuel mix is 24:1, one quart to 6 gallons, use TC-W3 certified oil and regular unleaded gas. That motor has silver plated aluminum connecting rods. DO NOT skimp on the oil.
Some things you should know: The coils in those old OMC motors are always shot (cracked) unless they have already been replaced. Also, if it has been sitting a long time, you should replace the water pump impeller. Carb cleaning may or may not be required according to whether it was stored with gas in it. They have those parts right here at iboats.
What other probably don't know: Those motors had a very toublesome seal on the bottom end of the crankshaft. And when the seal leaks, water goes up through the main bearing, into the crankcase. When that happens, expect the aluminum connecting rods to melt and come poking through the crankcase. Everybody sees those melted rods and blames it on the oil. 'Taint the oil, it's the water intrusion. If it were my motor I would pull the powerhead and replace the seal. "Too big a job" is no excuse.
For what it's worth, I was a Gale dealer mechanic at the time it was built.