ORIGINAL: BOUND_4_HELL
I have attempted to tune the needles on several occasions, but cannot get the burbling out with the 22x8, you can hear it burbling, gurgling and farting in this short clip of my Pitts in knife-edge at a 1/4 to 1/3 throttle with the 22x8 Xoar. Also in the video my exhaust pipe had fallen off the muffler, so it may also have something to do with all the burbling.
The power is great and it has never flamed out, but like you, I think it would be nice to have our cake and eat too.
Doesn't sound good.
What are you running for the ignition? Spark plug? Gap distance?
Do you have a hole in the firewall behind the carb?
Do you run or have you considered running a line from the carb vent into the fuselage?
Prop size shouldn't make any difference.