Give this a try if you think your having fuel problems because of Ethanol or non Ethanol fuels.Take 3 1 Quart jars and fill each one with a different grade of fuel and Put the Lids on tight but punch a small vent hole to simulate the breather hole in a fuel tank.
Set them on a shelf in your shed or garage for 3 weeks and then check the color of the fuel.You'll notice the Fuel with Ethanol will turn a nice brown color within 3 weeks.The next higher octane fuel will start to turn in 5 to 7 weeks and the highest grade fuel will start to turn in 6 to 8 weeks.The shelf like of E10 or E15 is 1/2 as long as the higher grade fuels.
The Low grade fuel is not regulated by % of methanol content.It may have alot higher content.My aunt runs a small mom and pop grocery store/gas station.They had they're fuel tested after the 10% Ethanol fuel was introduced and it was almost 20%.
One very bad thing about Ethanol is it's ability to absorb water.It can absorb over 10% of it's weight in water and separate in a vacuum filled environment IE(your float bowl)
Ethanol Will also deteriorate or desolve Non Alcohol-resistant parts,especially rubber and plastic parts.
Nice little read here if your intersted.
Edited by EricFromPa, January 19, 2013 - 08:37 PM.