Oil Mixture on 1970 evinrude

F1shermun

Cadet
Joined
Mar 31, 2009
Messages
7
I am new to boating. I have a 1970 evinrude 85hp starflite. I am not sure what the mechanic mixed the gas oil ratio at originally but it ran great and started with just a turn of a key. I used up my first tank of gas this weekend with seafoam and I mixed the next tank with seafoam and penzoil marine oil at 50:1. This seems to make it hard to start and it doesnt want to idle at low speed. I hope it is just a bit too rich. Any suggestions??
 

clemsonfor

Lieutenant Junior Grade
Joined
Sep 19, 2005
Messages
1,011
Re: Oil Mixture on 1970 evinrude

it will not be hard to start regardless of the mixture, well maybe like 3 or5:1, but even mixed at 25:1 your motor will fire off like there is no difference, it will just smoke more.
 

F1shermun

Cadet
Joined
Mar 31, 2009
Messages
7
Re: Oil Mixture on 1970 evinrude

Any suggestions as to what it might be? Once it is started it runs like a top, it just wont idle.
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: Oil Mixture on 1970 evinrude

Probably a dirty carb. More specifically partially clogged low speed jets.
 
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