Do I have to premix oil in this engine?

Question

Ive got an old boat I'm trying to get running again. Turns out just the fuel lines were pretty rotted, so Ive got all of them replaced. The only thing is, Im new to boat engines so I dont know if I need to use gas premixed with oil in the engine or not. its a mid 70's or 80's (i think) Mercury50 hp, what should I look for? Thanks!

Answer 1

You must premix the fuel for this motor. One pint per 6 gal. of fuel.  I've learned that the higher octane is better, there's such a small difference in price, it will give better performance.  Since this motor had been stored for sometime, I'd recommend that a professional mechanic check it out.  There are serious lubrication issues, particularly the needle bearings on the crankshaft.  Unlike auto engines, outboards have needle bearings.  When an engine is not prepared for storage condensation can cause rust spots on the crank.  They in turn can cause engine failure.  Also old fuel in the crab. must be cleaned out, and all the passages checked.

Answer 2

Go on line and seek out a manual on the engine.

Answer 3

if there is a reservoir for the 2 stroke oil it would be clearly marked. if not you will have to mix it your self there are measuring cops @ boat stores that you can purchase that would be a more precise way to measure.