Ethanol and two stroke outboards

[1975fflh]

Hi

Will running 10% ethanol in my 10/1998 Johnson 90 horse damage it?

It is supposadly 95 octane?

or should I pay the extra 6 cents a litre for normal unleaded.

[blaze]

IMO go with unleaded
cheers
blaze

[Ron173]

Mate, I wouldnt touch the stuff, especially in an older engine.

lots of manufacturers say not to run it at all, inc Yamaha.

Additives in fuel nowadays can attack seals in fuel system.

The high octane stuff is just as bad, the premium stuff, from shell, bp, caltex etc. was welll warned away from it with etec.

Just run straight unleaded, unless you have a newer engine and the manufacturer recommends otherwise.

[whiteman]

There are too many urban myths indicating ethanol is a non no in 2s's. I wouldn't.

Search this site for "ethanol" to get more info and also look at iboats.com

[tunaticer]

There was a thread on this about 6 weeks ago and a lot of data and negativity about using e10 in systems that have run unleaded prior.

One guy did an analysis of maintaining his fleet of boats and e10 was the cause of most maintenance problems for that yr. However he did also state that motors run solely on e10 did not suffer as those that had converted to e10.

Look for the thread and follow the links.

Jack.

[shags101]

the story i got from yamaha was that you could use e10 but it tends to absorb moisture from the air more than unleaded an if the boat sits idle for any length of time or in times of high humidity it becomes a big problem . an the higher octane fuels have additives that clean your fuel system an if you use it all the time it is not a problem but if you run regular them the high octane the stuff that builds up in your system comes free an can plug things like carbies an injectors ect up

[Gary Fooks]

I was at a meeting with the boss’s of the 6 outboard companies present when this was discussed.
It seems that we don’t have the same regulations as the USA when it comes to fuel tanks - and some tanks, especially built in tanks are not up to handling ethanol,
Also the water absorption over time is a problem that your weekly car would not notice.
Orbital engine company tested 10 identical outboards for the Federal Government and had problems with one of the ten ( 15hp Mercury 2 strokes) - but the others were fine. I have a copy of the full test results if you want to read them.

If you are using your outboard regularly - 1 or 2 times a week, and have a stainless or plastic fuel tank I would say go for it.

[FONT='Calibri','sans-serif']Gary[/FONT]

[FNQCairns]

Pay the extra 6 cent's, I do. Ethanol can make a mess of the die-cast aluminum the float bowls are made of in carb 2st engines also.

The ethanol all by it's lonely is passable, it's when water is around even in minute amounts that it all turns ugly with acids forming. When an engine cools it creates condensate internally which is bad enough but with some unburnt fuel still contained internally as normal, the combination happily sets about ruining roller bearings and any other surface the ethanol and water combine on.

I wouldn't give an outboard 10 years on the stuff in recreational use before some catastrophic failure or at least a failure that amounted to an engine tear down too place that was directly the result of the ethanol.

cheers fnq

[1975fflh]

Thanks very much guys I will stick to normal unleaded.