Start at the beginning. I don't think you have a big problem with the carb. I think you have some issues with the ignition. Look for a good rubbing block on the points. Yes I have had that critter fall off. No spark and no go. If the points are OK check the point gap on the high part of the lobe. If all of this is OK then look real hard at the coil. If you are running 12 volts and have a 6 volt coil you will get the coil hot and it will break down or quit. If it survives you will burn the points with too much current. Get a new coil rated for the voltage you are running and try that. Should be able to find one that is not too expensive. Same issues with 2 carbs is trying to tell you to look elsewhere.

Steve H