A little background… I have an 81’ Maxim 650. Last year I swapped the original air box for pods, but didn’t really notice much difference in the performance of the bike. The bike ran fine with plenty of power and throttle response. When I took the bike out of storage this season there were a couple of noticeable problems. The bike misfired until the engine was warm and there was a deceleration backfire. The misfire was tracked to a cracked coil and both coils were replaced along with new spark plugs and an oil change. After that the bike ran fine, good acceleration and plenty of power; except that pesky backfire. I think I tracked the backfire to badly cracked intake boots, so I replaced all four with new. Also, because I hadn’t cleaned the carbs in the last couple of years, I decided to give them a good cleaning. I did a complete carb breakdown with the exception of the butterfly settings as the sync seemed to need little adjustment. I cleaned every orifice thoroughly with cleaner and compressed air. Replaced the fuel/air needle, spring and O-ring. Checked the float needles and checked all the floats to make sure they were in spec and looked over all four diaphragms to make sure there were no holes or tears. After reassembly there is a noticeable difference in the sound from the exhaust, the engine stumbles when accelerating and bike has lost the pep that it had before. I set the fuel/air mixtures using a colortune plug but the bike can still be a little hard to start at times. Any suggestions on what I could be missing or something I may have overlooked?