Logo

Evinrude 140hp 1979 Fuel / Oil Ratio

Paul Bay

New member
Hi,

Ive just purchased my first boat complete with 1979 140hp Evinrude engine. good news however im stuck regarding the fuel to oil ratio.

Do anybody know what the fuel to oil ratio is? The previous owner stated that is 20:1 but on a website i found a ration of 50:1, does anyone know or where i will be able to find out??

Im new to this and not very technical so what will happen the ration is incorrect?

Any help / advice would be very useful.

Thanks
 
They all run on 2% or 50:1.
For normal use, not more nor less.
Use any TCW 2 (for mix in fuel) or TCW3 (Both mix in fuel and/or separate oil-tank) oil.
If planning to do your own service, invest in an original OEM workshop manual as well.
 
They all run on 2% or 50:1.
At least since 1964!

That's near enough 1 pint in 6gallons.

It includes engines produced in 1985 and a few years thereafter that were originally marked for 100:1


At 20:1 it will smoke excessively and might well foul its plugs.
 
At least since 1964!

At 20:1 it will smoke excessively and might well foul its plugs.

All with roller/needle bearings on cranks and rods.
Not only will 20:1 foul the plugs, but carbon up rings and exhaust in short time. That might be quite expensive!
 
The 100:1 ratio was for a short time because it failed and created pre-mature failure. Even motor's marked 100:1 should be run at 50:1
 
Back
Top