Ethanol and water

[outlawbusa]

I know there has been a lot of threads and discussion on here about water in the fuel. Mr Bogus has provided some great information on the issue also.

The feeling has gone back and forth if you should leave a full tank or near empty tank when storing your bike or other vehicle for a period of time.

Some of those opinions changed once Ethanol was used on a widespread basis~!~

I found this article in Cycle World pg 71 July 2010 that helps explain a bit.

Excessive Water In The Fuel
And Phase Separation
Ethanol attracts moisture from the atmosphere, chemically bonding with it to form an ethanol/water molecule. Water in the fuel causes engines to run rough, stall and can lead to internal damage to engine components. Fuel will naturally hold .5% water in suspension, but if water levels exceed this threshold the water drops out of suspension. The water/ethanol molecules are heavier than the fuel and drop to the bottom of the tank. This is phase separation. Ethanol provides a significant amount of the fuel’s octane, so when the ethanol separates and drops to the bottom of the tank, the remaining fuel is left without enough octane to properly operate the engine. Plus, the ethanol/water mixture is only partially combustible which can lead to severe engine problems.

 

[Kaptain Kanji]

Some of that quote makes sense except the "octane" part. Granted the ethanol will make the
fuel more likely to combust under a certain amount of pressure, but if the fuel has the proper amount of
octane producing chemicals to begin with, it's not going to make any difference and not going
to damage your engine. As far as the Ethanol producing "octane", that doesn't make sense either.
To the best of my knowledge, alcohol will combust under lesser amounts of pressure than gasoline will.
All in all, I just wouldn't worry about it. If you hear the engine cackling, go to a higher grade of gas.!!

 

[KvHotDog4]

When storing I don't see how any of this will matter, The fuel is pumped from the bottom of the tank in motorcycles, so if you have a full tank or a near empty tank anything that falls to the bottom will be burnt first no matter how full the tank is.

 

[blusmbl]

I tested E85 on a production vehicle program. Ethanol evaporates out of the remaining fuel rather quickly, so for something like our bikes it's really a moot point. It does retain water, though.

If you mix any fuel with ethanol content with a large volume of water, the gas and ethanol will separate completely, and by measuring the volumes of each and comparing you can calculate the ethanol percentage in the fuel you've been running.

I personally store with a full tank, and fuel stabilizer.

 

[outlawbusa]

I am a firm believer of stabilizers also...

Something else I learned (maybe true, maybe not) is higher octane fuels do better when the ethanol evaporates.

I tried to start a chain saw 2 months after last using it and had to get the carb redone...they said it was the ethanol. They also stated that if I use 93 octane in it that it would not be as bad and leave as much residue, again don't know if that's true or not but thought I'd pass it along.

 

[cipher5791]

Thanks for the info

 

[Spkrdctr]

Remember guys "ISO HEET" from Walmart will solve all wate/fuel problems. Just dump the bottle in the tank and ride until the tank is near empty. This guranatees you no water in your tank. Never store a bike over the winter with gasoline in it without a healthy dose of StaBil in the gas. Also you have to run the bike with the StaBil so that it gets into the carbs etc. before you store it.

Also ethanol is 105 octane. Just a tidbit of info.......