Test the fuel pump for output volume, vacuum, and pressure. True vapor lock, particularly on a stovebolt engine, is about as rare as finding the wicked witch of the west's flying monkeys hitching a ride on a unicorn.
The pump should deliver at least a pint of fuel in 30 seconds with the engine idling at normal speed. If it won't idle for 30 seconds on the fuel in the float bowl, fix the carburetor. Pressure at idle speed with the fuel line at the carb disconnected and deadheaded into a pressure gauge should be 3-5 PSI and the pressure should stay there for several seconds after engine shutdown. Vacuum at the pump inlet should be 10-12 inches of mercury and stay for several seconds after shutdown also. If the pump is low on volume but passes the pressure and vacuum tests, find the air leak or restriction between the pump and the tank.
If the fuel system checks out, look for a no spark situation with the engine hot.
Jerry
