Try swapping the plug wires and see if the smoking issue swaps sides. If that doesn't work try a compression test (you should do this anyway). Then if that checks out clean your carbs. Don't just spray carb cleaner on parts and think its clean. Use swabs, compressed air, etc. I'd also check your reeds and mske sure they are sitting flush. 95% of the times one of the things I mentioned will fix your problem. For reeds I'd go vforce if you have the cash or boysen. TORS eliminator kit can be found on F.A.S.T. or rockymountanatv. I have a motion pro one from rockymountanatv, and it works well. Just make sure you get an idle kit with the TORS eliminator kit, otherwise you'll have no way to adjust your idle. Sorry for any typos, I'm on my phone