It's not the carb itself that needs to be hot, it's the intake. The carb needs to stay cool, hence the thermal isolator/spacer between it and the manifold. Once the mixture leaves the carb, the fuel mist will want to fall out of suspension and form droplets on the intake manifold walls. Droplets don't burn, only fine mist will. The hot manifold reduces the droplet problem and helps vaporizing the fuel before it enters the combustion chamber.
Not the best terms to use here perhaps, but forgive me, it's my 3rd language
If the intake and venturi velocity is high, the mixture quality/atomization is better and you can get away with a cooler intake manifold. Ours, as I have come to understand, suffer from poor, slow flow by design, and that's why they came up with the lumps, to redirect and speed up the intake charge. Someone correct me if I'm wrong.
