I am working on an 04 Roadking with a cv carb. It pops through the exhaust when you let off of the throttle. I replaced intake seals and exhaust gaskets. It has the factory head pipes with straight through pipes. the end pipes are 2 1/4". Anyone have any ideas on this. I checked the plugs and it looks to be jetted right. Any help would be greatly appreciated. I didnt know if having the factory head pipes with the rear crossover and a straight through pipe on the rear would make this have this problem.