How to get ethanol out of my gas tank?

Question

I have a boat that has a 99 gallon gas tank ,. just filled her up but the gas has ethanol and now it is running really bad. should i draing the gas and put 100% prem. gas or is there like a fuel additive to get rid of the ethanol in the gas?

Answer 1

If you could remove the ethanol, the resulting gas would be seriously octane-poor.  And octane boosters are usually made from ethanol or methanol (just like ethanol only worse).

If you have fiberglass tanks, you are screwed.  Ethanol will dissolve the fiberglass resin, which will collect in the motor and tear it to shreds.

Otherwise, whats happening is one of two things:

1.  the ethanol (which is an excellent solvent) is cleaning the accumulated crud out of your tank and passing it through to the engine.

2.  phase separation.  Water that is dissolved in gasoline is not a problem for the motor.  But when it separates (which ethanol-blended fuel is prone to do), you get a layer of water and ethanol beneath a layer of seriously octane-deficient gasoline.

It takes a whole lot of water for phase separation to occur.  More than you would get from condensation.  You had to have taken on water from another source (from the pump, rain, or other leak into the tank).

But once phase separation happens, nothing can be done to improve the fuel -- it's a goner.

Ethanol blended fuels will not ordinarily present a problem for a well-maintained boat & motor -- it's that first load of E-10 cleaning out the tank, that causes problems.

Rebuild the carbs, clean the filters.  Drain the tank if you want, clean it out & you'll be all set for E-10.

Answer 2

Ethanol will stop up a regular gas filter very quickley.(water seperator) They now make filters specifically for use with ethanol gas. The filter problem is the only documented problem with ethanol. If the ethanol didn't destroy your gas filter, I'd be checking for excessive water in the gas. That's more likely the culprit.

Answer 3

Check the fuel/water seperator. See if it is full of water.  Hard to find non-ethanol gas.  Seafoam may help.

Answer 4

Everything has ethanol at the pump now. It is a fact of life. Ethanol binds with water, It raises the specific gravity of water till it floats around like garbage. If you had water in the tank to begin with(what boat doesn't) the load of gas will pick it up and you will be passing it thru the motor over a period of time. The only "cure" is to keep a full tank. However--- then the ethanol will whistle out your vent and leave you 10% short on fuel and a lower octane.(That is how much ethanol they can legally put in gas now!!) Stabil will not lock up ethanol.

Answer 5

Even premium has up to 10% ethanol. It does not matter what grade it is.