Do you have Facebook? If so, check with Preston Mason or Spencer Clipperton. Both sell used Banshee parts. Preston is in Harrisonville, MO. I bet it’s CDI. I’ve had the same tho my happen before and seen other bikes do the same thing.
I doubt you will feel any noticeable performance gains from the 33s.
You will gain power on top but your bottom end will likely suffer.
I'd stick with the 28s.
You won't see any benefit, and possibly loss, from running big carbs.
Until you're into the 10mm+ motors, there's no upside to the big carbs.
Stick with the 28s until you build something bigger.
Started all of a sudden? You didn't notice anything strange prior?
Carb jets clean? Once you put it into gear, you're putting it under a load which will consume more fuel.
I'd start with checking the carbs.
What about plugs?
Only pipes I ever had chromed weee the ones in the 450r chassis and the ones in the green Banshee. One set chromed at a place in Missouri. The other in PA.
TDR has been around forever and does great work. Call them up. Tell them you got the info from BansheeHQ. See if he has a dyno. I'm pretty sure he does. He can get it tuned in for you.
https://bansheesuperstore.com/