I have 3 running Kt100's on 3 different. karts with WB 3A carbs that I've been able to make perform just fine. I bought a new WB 20 at a kart shop about a year ago and no luck at all with it. I've adjusted pop off and fulcrum arm. Issue is it's starving for fuel. I took freeze plug out on low circuit and hand drilled the smallest hole from .025 to .033. It's still starving no change. Current pop off is 5 and holding 3lbs. Fulcrum arm at .06 from carb gasket surface. Adjustment screw way out 4 rounds