Ethanol and Outboards.

[driver0606]

I am wondering if my 1989 9.9 Evinrude is resistant to the ethanol now found in petrol. No doubt so are a lot of other people. Maybe there is a year after which outboards generally will be OK. Does anybody know, please?

 

[Vitesse]

Good question.

American boat forums discuss petrol additives and many there seem to use such things religiously.

I asked my engineers (Yamaha outboard dealers) and they reckoned it's not a problem here (or at least with my 2000 motor). If they wanted I'm sure they'd be happy to shift bucket loads of Ring Free.

I'm still not sure what the answer is, mind.

 

[Johntheoil]

Hi there, the 2 main issues with ethanol in gasoline are:
Possible degradation of the hoses and gaskets in your fuel system (think carb and fuel lines), which considering the age of your engine (1989) has never been considered in the design.
The other major problem (especially with seldom used engines like most marine pleasure boat engines) is that ethanol is very hygroscopic, so will absorb water a lot more readily ( from residual water in the fuel tank, from condensation, or from leaky fuel fillers) than traditional 'fossil' fuels.
This means the water doesn't seperate out in the tank or carb float chamber, so you won't know if it present until your engine doesn't work because of the 'quality' of the fuel won't support combustion, or there is corrosion in your carb.
I'm guessing as a 1989 engine it may be 2stroke?......if so it might not be such an issue, but I'm sure other better engineers on this forum can give better guidance.