So my bike ran just fine this fall. Had to have float bowl gaskets replaced do to leaking fuel. Anyway was nice out and tried starting it yesterday and it floods out in a matter of a couple turnovers and starts backfiring. Pulled plugs and turned it over to dry it out and cleaned plugs. New plugs last year. It will attempt to run if u keep starter engaged now but still wanting to back fire. Only thing I can think of is something is screwed up from when they put carb back together. Any ideas. Needle and seats?

 

it could be a stuck float or valve if you used too much adhesive to put the float bowl gaskets on. then the gas would feed in through the main circuit. i would def check the carbs again. it wouldnt hurt to check the choke plungers to see if they are stuck..... thats where i would start.

 

Check the float valves. They're really the only things that would make your carbs flood.