Gas/Oil ratio for old outboards

[portoffshore]

I have a 1950 Evinrude 7.5 Hp outboard (4434-12039),Its recomended (on the fuel cover of the motor) a 16/1 ratio of a high grade oil of SAE 30 or 40 body, such as Mobiloil outboard or comparable straight mineral oil. Do I really need to use such a rich mix of oil if use the current brands of outboard oil rated TC-W2 or TC-W3? This Motor has low hours and runs great (starts on the 1st pull) therefore I don't want to damage it, but it smoke's alot more than my 6 HP Johnson (50/1 ratio) and I would like to reduce the amount of oil/smoke that I release on the lake.

 

[wikelam]

Re: Gas/Oil ratio for old outboards

i have a 53 3hp evinrude and i use the 50:1<br />no problems with it. but this is just me, others may have more input on this.

 

[wikelam]

Re: Gas/Oil ratio for old outboards

OOPS!! '54 not a '53

 

[Lark40]

Re: Gas/Oil ratio for old outboards

There's been a lot of opinions written on this topic. Most debates are about the wisdom of using 50:1 instead of the original 24:1 in larger 1957-1963 J/E engines .<br /><br />Those opinions don't apply to your engine, as it has sleeve bearings and looser tolerances which require thick oil. I would think no more than 24:1 with modern oils. I've never heard of another owner besides wicklam running 50:1 in that era engine.