When it 'bucks and stumbles' is there black soot smoke from the exhaust?
If yes, then you are getting raw fuel into the engine, likely overly high fuel pressure or needle & seat.
If no, then you are not getting enough fuel thru the carb for many different reasons all of which will be solved with a good rebuild.
It might be ignition, the carb gets blamed for ignition problems and the ignition gets blamed for carb problems - I just don't think so in your case.

A shop is where you wash your hands before you pee.