I got my freshly cleaned carb back into my 98 400F (Bone stock) today and after kicking the crap out of it, it finally fired up, but it's running choppy (backfiring and popping out the exhaust ). This bike ran great before being put away for storage in the winter. I did an oil change, new plug, tank flush, but I did move the fuel screw when I had the bowl off. Could this be a simple matter of re-adjusting the fuel screw by 1/4 turn at a time to get it running right again? My guess is that I'm getting too much fuel. Even after warmup, the bike requires choke to fire back up and won't idle on it's own. Would greatly appreciate any help you can offer. I'd love to be able to ride a bit tomorrow.