Floatless Carburetors
I ran karts for nine years and never had any success with float type carburetors, for all of the reasons already discussed.
If you're having problems with your Walbro or Tillotson carbs, your pop-off pressure probably isn't set correctly. The pop-off pressure on these carbs is absolutely critical. The diaphragms and pop-off valves need to be changed regularly. I changed them once a month. If the diaphragms are worn, the pop-off will vary. You will also find bad pop-off valves that are new.
The pressure needs to be set at 9.25psi to 9.5 psi. You can change this by bending the little tab which has a spring under it (it takes some patience). I am sure if you have the pop-off set correctly, the Walbro or Tillotson won't give you any problems. If you're fitting a walbro to a motorcycle engine, you will need a pressure tap into the crank case with a hose connection. If it's a Tillitson, you will need a special intake manifold that has a pressure port leading to the crank case. (probably special made) I also preferred using the head temp rather than exhaust temp because it was more stable and more accurate to the situation.