[THEFERMANATOR]

That engine uses the YAMAHA CDI unit, and they are VERY reliable. A piece of trash sitting in front of one of your main jets would cause ALL of the issues you describe. Drain the carb bowls and look for debris. While you have the drain screws out, spray some carb cleaner in there. The main jets are located right behind the bowl drains, and they can be removed with the bowl drains out. Another thing you can try is to take it out and one at a time pull a plug wire off until you find the cylinder that doesn't change with the plug wire being off.