My bike sat all winter and when I tried to start it the Ignition Control Unit started smoking. I replaced it and it started fine. However when I took the bike out, it would occasionally backfire and hesitate on acceleration.

I thought the gas might have been bad so I have put many miles on it. I have also replaced the air filter,fuel filter, oil filter and spark plugs (minor maintenance). I also tried to clean the carbs and noticed signs of the backfiring in one of the carbs. I cleaned it out to the best of my ability (first time trying this).

It seems to be running lean and almost backfiring more. Could this be the ICU I got on ebay was bad or do I need to do a better job of cleaning the carbs? I would have replaced the ICU right away if they weren't so expensive.