if the fuel is pump gas that stuff is not designed for what you are doing. change the fuel.......something with a higher boiling point, i don't know if av gas would help, race gas is $$$$
insulate everything possible, fuel lines, 2x gaskets, etc.
get cool air into the engine bay, maybe some of those fancy hood vents.
sounds like you are trying to tune around a heat/fuel related problem.
i have no weber experience and this information is worth what you paid for it.....
how bout some pics just for trying?
