[Eljaro]

The problem is the fuel trapped inside the pump conducts in the carb body. The carb heats up and the fuel inside the pump conduct has probably some air trapped along the way, which expands with the heat and pushes the gasoline out the pump jet. The pump draws the gasoline from the bottom of the bowl, so a lower bowl level should not be of much help.
I think only shielding or some type of evacuation of the hot air should help.
I am going to try a pair of Muffin type fans mounted behind each side vent and improve the heat-shields I have already made.