Todd, I was using 5% sig champion fuel with a McCoy/hangar 9 #9 ducted fan plug. I have used this setup for every ducted fan flight I have ever made (for 2 years) with no probs until I switched the pipe to the JMP system. I switched so I didn't have to keep replacing heat gaskets as often. Strangest thing I have ever seen (at home, at work I see some wierd stuff). Thanks, Mike L.