I ride an 03 anniversary lowrider, stock carbureted TC88, has about 65k on her. Suddenly developed a ticking or tapping noise that sounds like it's coming from the rear cylinder. Also at the same time the bike got louder and again it sounds like it's in the rear cylinder. It sounds as if someone had taken the baffle out of that pipe. That's the only way I can describe it. And also she's running like shit now. Does anyone have any ideas or suggestions or has experienced this before? I would really appreciate any input.