Today's Ethanol laced fuels evaporate at a much higher rate than normal "gas" and that is your problem. If you let the car set for more than a week all the fuel in the carb will evaporate and you wind up having to crank the engine for a while to fill the bowls again. You don't find this problem with fuel injected cars since they all use electric pumps and run on high pressure. You also won't find this problem with a carburetor setup when using an electric pump.

With the crap we have for fuel now days you basically have three choices. Change to an electric pump and eliminate the mechanical pump, add an electric pump with a check valve to bypass the mechanical pump so you can fill the bowls before starting, or fill the bowls manually before starting.

Those are pretty much your options. Good luck.