Honda Shadow foorumilta bongattua:
I am a small engine tech, lawmowers weedeaters, chainsaw, etc. I now deal with Ethanol everyday, as our area never had ethanol added to gas, until this past fall.
Some scenerios for you:
Man stored his lawmower this past winter just like he should, ran it out gas and emptied the tank, etc. Puts fresh gas in this spring and it starts just fine and runs perfect. Mows his yard, then next week when he tries to start it, nothing. Will not run. Brings it to me, I pull the bowl nut/jet out, clean it and it runs fine again. Why? Because ethanol has softened all the normal varnish build-up in the fuel system and now the varnish is plugging the small passages. Once it's cleaned ot, it will no longer be a problem, but the first use will do it everytime, if the system is not perfectly clean, and not used regularly. BTW, it's shown that ethanol does this to gas station storage tanks, that have never had ethanol in them. The varnish washes off the walls, and settles to the bottom, as sludge.
Scenerio #2
Man has his lwanmower cleaned up from his first experience with ethanol, mowes his lawn a couple months, always using the same gas he bought 6 weeks ago. Today runs out of gas and won't start after refill. Brings it to me, and I pull the bowl nut/jet, and drain all the water out. Why? His fuel can had a high concentrate of water. Ethanol "inhales" moisture from the atmosphere, at an alarming rate. Just set a shallow pan of gas out and watch how soon it begins to cloud up. That cloudiness is moisture. If you store gas in a can, keep the lid tight, and don't keep it more than a month at a time. If you have bike stored, keep the tanks "FULL", less atmosphere to absorb moisture.
All the manufacturers I deal with, claim that the rubbber parts used in their carbs and fuel systems, for last ten or so years, will handle 10% ehanol without degredation. That seems to be the case, as I see it so far. However the loosened varnish, and also the corrosion from moisture seem to really kill fuel systems.
BTW, I ride my Aero to & from work everyday. Same route, same speeds, etc. If I use gas with ethanol, I get about 38mpg, and without, I get about 42.
Hope this info can be of some help to someone.