Quote Originally Posted by Substance View Post
also do you know if the length of the burner pipe has any effect on performance ??
I have it at 8" of pipe from the shortest point of the throttle holes to the burner pipe end this is square cut

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Mine is 7" here. I've only built the one so I don't know how much effect that extra 1" will have. As I said I used an 1-1/4" nozzle and I find it runs well with 1-3/8" overhang. This keeps the primary flame wide and short.