Another approach you can try for priming your engine (I use this one with the afore-mentioned hot engines), is to plug the exhaust with your finger and turn the engine over quickly, either by hand or with a starter. This will pressurize the tank and "blow" the fuel to the carburetor. If this works, you don't have any major tank issues, as this requires the pressure line, tank and supply line to be "tight". With this method, however, it is important to turn it over relatively quickly, with minimal time between revolutions. It will take a little longer than the carb choke method for fuel to get there.

J