http://goldwingdocs.com/forum/viewtopic.php?t=14679Ethanol is the scourge of owners of motorcycles, boats, and many other gasoline-operated vehicles and implements. E10 (10% ethanol) is pretty much the only available gasoline in most of the country now, with a few stations offering ethanol-free gas. And E15 (15% ethanol) is coming soon, recently approved by the EPA for 2001 and newer cars - even though the car manufacturers don't want it, and it is not approved for use by any motorcycle manufacturer either. You can thank the ethanol lobby for that.
"E15 won't be a problem - I'll just select my regular E10 on the pump," you may say. Well, there is a problem - the pipes and hose of the fuel pump contain about 3/4 gallon of whatever was last dispensed - and that could be E15. 3/4 gallon isn't much when you're pumping 15 gallons into your car, but when you're only pumping a few gallons into your bike, which doesn't like ethanol to begin with, 3/4 gallon makes a big difference!
What's the problem with ethanol? The biggest problem is phase separation. Like brake fluid, ethanol is hygroscopic, which means it bonds very easily to water. If there is moisture in the air (which there always is), the moisture bonds with the ethanol. The combination of water and ethanol is heavier than gasoline, so it falls to the bottom of the gas tank, where the pickup is. Let your bike sit for any length of time, particularly with a partially-full gas tank (because the air space left will contain moisture, and will expand and contract with heat, sucking in more moisture-laden air), and your tank will have a layer of water/ethanol mixture on the bottom. This is called phase separation. Guess what gets sucked into your engine the next time you start it? The water/ethanol mixture will burn in your engine, but it will burn much leaner and hotter, with the potential for serious engine damage as a result.
Ethanol is particularly corrosive to plastics, rubber, aluminum and fiberglass when compared to straight gasoline. If you have a vintage bike with a fiberglass tank, and are running E10 gasoline in it, the tank is likely swollen and on its way to failure as the ethanol breaks down the fiberglass. Many bikes have developed leaks and problems from swollen gaskets and failed rubber hoses and seals, all as a result of E10.
When E10 is allowed to sit for a long time, particularly somewhere where air can get in, like a normal vented gas tank, the volatile portion of the fuel will eventually evaporate. What's left is a milky goo. This goo eventually hardens into an amber solid, which then cracks into tiny pieces - heading directly into your carburetor to clog jets and cause failures.
Two stroke engines definitely have problems with E10: ethanol breaks down the lubrication provided by the fuel/oil mixture, leading to engine seizures!
So what is the solution? Well, you can check out the web site
http://pure-gas.org to try to find a gas station near you that sells ethanol-free gas. Hint: many boat marinas sell ethanol-free gas, because with the added moisture in a boating environment, E10 plays havoc with boat engines.
Or...you can make your own ethanol-free gas. Yes, you heard me right! Make it yourself! I never even thought about doing this, until I read the excellent article "Removing Ethanol from E10 Fuel" by Dave Searle in the December 2012 issue of Motorcycle Consumer News - my absolute favorite magazine. If you haven't got a subscription to this magazine yet, stop reading this right now and go subscribe! I promise you won't be sorry. I've using a few pictures from Dave's article in this article.
So as you can guess, you don't actually make your own gasoline, you take regular E10 gasoline and remove the ethanol. Because ethanol boosts the octane in gasoline, I recommend you start with premium gas. Removing the ethanol from the premium will in the process lower the octane to the equivalent of regular gas. If you start with regular E10, you will need to add an octane booster, available at any auto store, or Wal-Mart.
So how do you remove the ethanol from E10? It's quite simple, actually - just add water! Remember, ethanol binds strongly to water. All you need to do is add some water to the gasoline, agitate to make sure it mixes well, then let it sit for a few minutes. The water will bond with the ethanol, and it will phase-separate out, falling to the bottom of the container.
How much water do you add? Well you can't add too much. If you don't add enough, then it won't remove all of the E10, and what E10 does bond with the water, will separate to the bottom of your container. If you add too much, the available ethanol will bond to the water, and the remaining water will separate to the bottom. You'll then have three layers: gasoline on top, ethanol/water in the middle, and water on the bottom:
