I built my own 2 into 1 collector and used a 4" truck turn down open pipe on my Aero without any tuning to the carbs. I rode it that way for many years, sounded GREAT but now it pops a lot every time I decelerate and it is obnoxious. When I say pops it sounds more like a backfire but I'm not sure if that is correct. I tried putting the stock pipe back on it, but it still pops on deceleration. Looking at doing a complete carb rebuild and tune (re-jet) to put the open pipe back on. Do I need to use velocity stacks, or can I leave the stock intake? Also could I have done some internal damage to the valves or something else?
