I run mine with a pitts, and my brother runs his with a pitts, and we have not problems at all. He was having problems with his at first, but it was fuel tank positioning. Once we fixed that, it was all in the tuning--mainly low end. You have to remove the limiters to get it right. Of course, air leaks here and there will give you fits, but not enough backpressure will not be a problem. If that is a problem, then your real problem is fuel tank position. With proper tank to carb centerlines, you don't even need backpressure. However, we rarely get that in our models, so we rely upon the backpressure to help push the fuel to the carb. I'd bet if you raised your tank slightly, you wouldn't have needed that much backpressure to get positive fuel flow.