Eska 1747C (1973 air-cooled 7HP) oil ratio

[guy48065]

I just bought this at a yard sale today. It's my 3rd old outboard and I bought it mainly because it has a twist-grip throttle and my others don't. The problem: I can't get it to keep running. As soon as I got home with it I stuck it in a barrel of water & fired it up. It ran strong in neutral for a minute then died. Not much luck after that. I was pretty much out of fuel so I put in a half tank of some 50:1 chainsaw mix I had handy. Still wouldn't run more than a few seconds and is very smokey. Plug looks good & is gapped correctly.
Got out the manual and see it needs 24:1.
I have several related questions:
What oil should I use in an air-cooled outboard and at what ratio?
I often see recommendations to run different ratios than original but if I understand 2-strokes correctly this affects the A/F ratio. There's only an idle mixture adjust on this engine so if I run 36:1 (or other) will I need to rejet?
Should I be adding a lead additive?

I'm hoping the motor initially ran good on the small amount of original fuel in the tank and if I put the "right stuff" in the tank I'll be good to go.

 

[steelespike]

Re: Eska 1747C (1973 air-cooled 7HP) oil ratio

Fuel mix for 70-73 motors is 24:1, 5.3 ozs per gallon Quote"Use a good grade of oil intended for outboards".TCW3 rated oil is fine.
Fuel mix won't affect operation except to make it smokey.Running a little too much oil is ok.Just don't short it.More than likely the fuel system is gunked up from standing around for months or even years.perhaps many times over the years.All the Eskas and Clinton motors are finickey at best.If you can get it running good without investing too much money feel lucky.Then sell it and put the money toward an Evinrude or Johnson 5,5.5 6,7.5 or 8 hp from the rarly 50s to the 80s.Smoother,quieter,and even the 5 will probably outrun the 7 Eska,Perts are much easier and more reasonable to find.Many routine parts are right here at iboats.

 

[guy48065]

Re: Eska 1747C (1973 air-cooled 7HP) oil ratio

How do you feel about the advice that oil has improved a lot in 35 years and running 36:1 is a good idea on an old motor?

 

[CATransplant]

Re: Eska 1747C (1973 air-cooled 7HP) oil ratio

Run it at 24:1. It's a 35 year old air-cooled outboard with a lawnmower engine on the top. If you want to keep it running, don't stint on the oil.

Good luck with it. My prediction is that after about four trips on the water with it, you'll be looking for a different outboard. Don't forget your oars or an electric trolling motor. I guarantee you'll need them.

 

[guy48065]

Re: Eska 1747C (1973 air-cooled 7HP) oil ratio

Is it the Tecumseh engine or the Clinton lower that's going to fail? I'm a big fan of simplicity and this Eska looks as simple as it gets (OK my British Seagull is even more spartan). According to 'net sources there's a bazillion of these wearing various brands, not counting all the 2-stroke Tecumseh-powered small snow throwers and lawn mowers, so parts availability shouldn't be an issue.

 

[steelespike]

Re: Eska 1747C (1973 air-cooled 7HP) oil ratio

It is mostly the power head.It is finicky at best unreliable at worst.Ignition failure is common parts are a pain and can be expensive.Impeller is weak
a common problem.Those with a clutch usually it doesn't work.It vibrates,is noisy,underpowered and unreliable.
Your Sea Gull is twice the motor and has a very strong following.
There is even a group that races them.