if you go with the byron or TGA pipe that is telescopic and adjustable, you may need to lengthen it to about 1" longer than the 12 1/2 ?? inches they call for. I was getting lean runs, blown plugs, loose head bolts and loss of power and couldnt figure it out, "it was my first DF" then a friend from atlanta told me to lengthen the pipe to 13 1/2 based on his experience. IT WORKED, from that day on with no more problems. Also get the JMP System 1 o-rings that are WHITE , they will last twice as many flights as the red. I always changed my plug after 3 flights and my o-ring after 6. Probably could have gotten away with more but they are cheap parts. russ