Do you know what mix you were running? I have only heard of that with people running the home made stuff made with waste cooking oil.
I was going to pick up a used kit from a guy who wanted out. It was quite a large kit and he wanted to give it away to a non profit, but would sell it. Once I looked into how to get the nasty oil from the places around here, I backed out.Brian, glad to hear you didn't get the kit, they are way overpriced, and you can build them yourself, particularly if you buy Girl-Mark's book, very detailed on building one.