Fires up then stalls

I'm not familiar with the 240 - are the 240 electrics 12 volt?? If so it probably has a ballast resistor in the ignition. And a burned-out ballast resistor will cause exactly the starting problem you are seeing. Try shorting across the resistor terminals with a short jumper wire, or feed the ignition coil directly from the battery and see if the motor now runs.

Another possible cause is restricted fuel flow to the carburetor. If the motor runs a bit longer with the choke pulled it's a fuel flow problem. Pull the fuel line off the carb and check for a solid flow from the fuel line. If you get just a dribble something's clogging the line (plugged sediment bowl, trash in the tank covering the fuel outlet, etc)

Where in Rochester are you located??

May be also you are a bit like me, I tend sometimes to hurry a bit too much. Just double check your plug wires in relation to fireing order. I wired one of these in a hurry once, went wrong way around distributor. They will make an attempt to start this way, as two plug wires are right. The two wrong ones however kill the effort.