have a 09 rk with a rush exhaust and took the stock baffles and put some bct qq baffles the head pipes, they sound good when im giving it throttle but i notice a metallic popping noise at certain speeds and when i go from a stop to a go... talked to bct and still getting the noise.. any ideas how to get rid of it? it tends to go away alittle when the bike is warm, and is it too much backpressure to run the bct baffles with stock rush baffles in too?