Pardner, I don't know a thing about the AI on the America since I haven't looked into it yet but in general, this is how it will work:
A hose from the carburetors attaches to the vacuum switch which open/close reed valves. The reed valves can be located on the engine cases or cylinder head. Anyway, sounds like you have the reed valve part solved. Now, the hoses that come off the vacuum switch which often looks like a metallic canister will go to the airbox at a minimum. You should plug the opening on the airbox probably. If unburned crud doesn't hit the reed valves to be burned, it is supposed to go into your airbox. The main issue you seem to be having is that when you removed the hose from the vacuum switch to the carburetors you left the nipple unplugged/uncapped. The hose is there to provide engine vacuum to the vacuum switch so if the nipple is unplugged when the hose is removed, the idle will race. You will be able to make the bike run IF you run with full choke (basically an enricherer and not a choke) but if you twist the throttle, the bike will die as this screws up the enrichener circuit. If the bike starts, it will idle at about 4K rpm likely. DON'T try and turn down the idle. Find the nipple and put a cap on it. Some folks use rubber vacuum plugs but this is a mistake as they deteriorate in no time and crack and you will be back to the same problem as not capped at all. Use vinyl caps which don't break down from engine heat. If I recall, there are vacuum spigots on the top/engine side and also on the carb holders (not sure why) and there is probably another for the TPS which will be a thin vacuum line going to the igniter to provide throttle position info. You don't want to mess with the TPS vacuum line.
