When it stalls next time
Drip some fuel down the carb throat or spray some carb cleaner in there
If the engine fires right up you have a fuel supply problem.
remove the fuel cap & try again
Problem goes away = blocked fuel tank vent
If it makes no difference
Pull the fuel line off at the pump, remove the fuel cap and blow back up the line
Problem goes away = debris in fuel tank plugging the outlet
No joy then remove the fuel cut off solenoid from the carb & check it's operation
Engine does not fire with the carb cleaner / fuel in carb = electrical problem