If you have assembled the carb with silicon, then you may well have created your own problem as the silicon spreads out when the parts are re-assembled & it oozes into passages where it aint s'posed to go, blocking fuel & air passages.

Silicon is for fixing drains. I won't have it in my workshop as it seems to cause far more problems than it cures. I use "Cat red"

If you HAVE used silicon in the carb instead of gaskets, then a new gasket kit will go a long way to fixing it.