OK, time for a newbie question...My 2000 426 backfires on deceleration. I haven't been riding in about a year, the last time I did ride it, it was backfiring, so after doing a search on TT, I figured the muffler might need to be repacked, so I did that. Just got back from riding over the weekend, still backfires. I have a White Bros 1st Gen E Series Carbon Fiber Pipe w/ the White Bros head pipe as well. The pipe has these "tuneable discs" at the end of the muffler. I think 10-12 come with the muffler and you can put more on or take some off. Think I should try messing around with these discs or do you think it would be jetting or ???