In general poor hot starting is associated with too much fuel, not too little.
The engine can run off the fuel in the carb bowls for a little while, and they should be full. If vapor lock was the issue I'd expect the engine to fire up, run for a while then stop.
Try shutting the engine down by cutting the fuel and letting it stop with the ignition still on. Then give it a minute or two, turn the fuel back on and go for an immediate start. If it starts up under those conditions I'd suspect that expanding fuel (due to heat) in the lines is being forced into the carb and overflowing the bowl and flooding the engine.