I've been helping a friend get an ultra lite ready to fly and found out the hard way how fast ethanol eats older fiberglass fuel tanks. Late last Thursday night we got the engine started (one pull on the rope! Rotax really is a nice engine!). It was late so we let it come up to temperature and shut it down and called it a night. Friday evening we decided to taxi it around to see how it felt. It tried to start a few times but would not. Two hours of tugging on that stinkin' rope and it was time to quit for the night. Saturday had the same results, we even tried four sets of new plugs. That's when I noticed little black particles in the fuel filter. Crap! Older fiberglass tanks and 91 octane car gas. Over night the ethanol had done it's job. I would not have believed it had I not experienced it first hand. There was goo in everything, The fuel filter, the carb.,the pistons, everything! I had planned to slosh the tanks on my series 6 but not now, av gas only. My wings are already done so all it would take in my mind is one little spot not to get sealed and I wouldn't be flying for a while.

My question is, has anyone had first hand experience, or really heard of anyone having a problem with av gas and fiberglass thanks? If I have to I will get the new tanks from the Mcbeans but I will never use car gas in my plane after this experience.

Steve