You MUST balance the carbs after any work and adjust them. I assume that you cleaned the bowls and checked for leaks in the floats. Sometimes floats get holes in them and fill with petrol (gas). Have you changed the filter set-up ( air box) to accept K&N filters or such like? Have you checked the intake gaskets for leaks. If you have changed the intake you must re-jet. Basically, if you want it to breathe more freely to get more power ( and an earlier death for you and the bike) you have to increase the main jet size. Traditionally we used to \