I have talked to Luv2lean about his 950 and his runs perfectly. No back-firing nothing. His is an '04 with the Akrapovic, Home made air box mod and the needle's raised one notch. He still has the canister crap on his bike but the damn thing runs good. There had been some mention of KTM using different jets with different years. I havn't confirmed anything other than my '05 compaired to an '04 which responded differently to the carb mods. I too thought it was kind of wierd but I still don't have an answer.