1956 evinrude 7.5... fuel-oil mixture?

heloman

Cadet
Joined
Apr 25, 2002
Messages
10
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

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 1956 evinrude 7.5... fuel-oil mixture?

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

jegervais

Chief Petty Officer
Joined
Jan 18, 2002
Messages
646
Re: 1956 evinrude 7.5... fuel-oil mixture?

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

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: 1956 evinrude 7.5... fuel-oil mixture?

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 <br />$800. I have the bill posted above where I keep my oil. Be careful, Spike
 

NitroBoy543

Seaman Apprentice
Joined
Mar 30, 2002
Messages
40
Re: 1956 evinrude 7.5... fuel-oil mixture?

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

Vice Admiral
Joined
Feb 24, 2002
Messages
5,518
Re: 1956 evinrude 7.5... fuel-oil mixture?

Hello Heloman.<br />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.<br />Enjoy your boat.
 

alcan

Commander
Joined
Dec 14, 2001
Messages
2,505
Re: 1956 evinrude 7.5... fuel-oil mixture?

Hi heloman<br />The 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.
 
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