Motorcycle Repair: noise, lean condition, vance and hines

Question
I have a 03 super glide. The dealership changed the pipes to SE II slip on's. Rejet the carb, changed the air cleaner. Everything was great. I changed the pipes to Vance and Hines big shots. Now I get a pop when I let off the gas. What did I do wrong? How can I fix it?
Thanks for your help.
Doug

Answer
The poping is from not enough back pressure on the exhaust system and probably a lean condition. When you changed you pipes you needed to check the jets in the carb again, due to the fact that you opened the exhaust more. If you rejet and still have the problem you might try retarding the timing a slight amount and that might help.
Good luck and happy riding
Mike