Hello im going to start off by saying that i own a 2007 sdi. The sled has got a recent rebuild with only 1000 miles on it. My problem is that after it gets warmed up it likes to back fire. It does this pretty often after a hard run or letting off the throttle. Its very easily seen at night with the blue flame shooting out of the exhaust. I called the dealer and they said thats what all sdis do but i have a hard time believing that anyone would by a sled that backfires at every stop sign.