packing

Can exh packing effect jetting requirements? 4k stumble. 99 Vmax with 4-1 Kerker, stage 1 jet kit and drop in K&N. I have been doing some reading but a couple questions remain. I'm seeing a stumble/miss from around 4000 to 5500 rpm, feels like starvation. I'm guessing when Vboost starts to...

How often do you have to change your exhaust packing? I have a Mark's full system 4-2 with 14" cans. The bike is an 06 with 12,000 miles. About 8,000 of those miles are with this exhaust. I think it sounds a little different. I've been using a half helmet this year and usually listen to music...

http://www.youtube.com/watch?v=wYE37Xcc5ss&feature=channel&list=UL