[heloman]

I recently bought a 1956 evinrude 7.5 (7520-03709). Inside the cowling the tag says to mix the fuel-oil mixture to 16 to 1 with 30-weight engine oil. A friend of mine says that if I use regular 2 stroke oil I should then mix to a ratio of 32 to 1. What should I do? Thank you to everyone who replies.

[JB]

Howdy, Heloman.My manual on early Johnson engines, which were identical to the same period Evinrudes, calls for a 24:1 ratio.With the huge improvements in outboard oil since then I think 32:1 would be okay. Use only alcohol free unleaded, 87 octane.Good luck.

[jegervais]

I concur with JB. I'm using 32:1 in my 1960 10hp Johson SeaHorse.-John

[steelespike]

Im pretty conservitive. Stick with 16:1 dont mess with oil ratio,Oil ratios change with engine design more than oil technology.I once ran an engine with 1/2 the required oil by mistake took half a season before i noticed a problem.Cost me $800. I have the bill posted above where I keep my oil. Be careful, Spike

[NitroBoy543]

well todays oils are much better than the ones in 1955. i have a old evinrude 7.5 from 1955 and im using about 1-24. it seems to run nice and cool

[rolmops]

Hello Heloman.1:32 is fine for your engine.But do stay away from 30 weight oil.The only oil that is right for outboard engines is TC-W3 outboard engine oil,which is available from many producers.Enjoy your boat.

[alcan]

Hi helomanThe decal on your motor reads, that you can use 30wt.non deturgent oil at 16:1, that's only in a pinch, only when you don't have the approved two-stroke oil. That's why the extra oil,for safty. The correct recomended mix is for 24:1 BIA\TCWIII. Your 7.5 uses babbot style bearings instead of rollers or needles. I would stay at recomended ratio. If you have your motor adjusted properly you won't notice much more smoke or have any more than normal spark plug wear.