Problem solved,took the tank apart but didnt find anything wrong,then I soldered a brass tube to carb & routed silicon tubing to the fuse interior,that did the trick. I put the 20X6 back on and it ran good,will try a 19X8 next. The low end on this thing is taking so many turns in to lean it out its incredible, but as long as its 4 stroking in mid range and not quitting/surging, it still could go in more. My faith in Brison is starting to come back.