Re: sea king 5hp. shaft lenth
Motors in those days were designed to run on wooden boats with a keel and the cavitation plate ran well below the surface. Your length is fine----SHORT SHAFT!!!
Sure, I can tell you just about anything you would want to know about it. I was a full time dealer mechanic for a Gale dealer when it was new. And your question is----??????
Fuel mix is 1/2 pint per gallon (16:1)
Lower unit takes 90 weight outboard gear oil
Magneto is typical OMC Universal Magneto, used on a bazillion motors. ALL OMC coils of those years are shot (cracked) unless they have already been replaced. You are wasting your time if you don't look at them first (after a compression check). New coils available right here at iboats.
Lower unit is a modified Johnson TN models (different drive shaft)
Just about everything else is Gale, although Evinrude had a similar powerhead and carburetor. You won't see many Evinrude versions, but a ton of Gale versions.
Water pump impeller is NLA, but a 3hp/5.5hp/6hp/7.5hp Johnson/Evinrude impeller will work by enlarging the center hole.
DO NOT, do not, do not, remove the side covers off the cylinder block. They are extremely difficult to reseal. Original service manuals said to return it to the factory for resealing (The factory is gone).