Automobile Enthusiasts

When the fuel system is overheated, hot air expanded in the system will shut it down until it cools, then it starts right up again.

I mention this because some of these these old straight sixes used to have a hot air stove under the carb on the exhaust manifold. It opens when the manifold is cold to warm the carb and give a smoother idle, but a mechanical thermostat closes it after warm up. Sometimes this themostat rusts and sticks open providing heat even after the engine is completely warmed up causing the float bowl to get hot.

Look under the carb for a chamber that extends upward from the exhaust manifold. There may be an exposed thermo-coil there that opens and closes a trap door inside that could use a little WD-40. Happened to me once.