If you can find out the problem I´m sure there are a lot of riders that would like to know. I´ve been reading the dicussions from TL1000R ´98 to ´02 and this is an on going problem. I was thinking about buying a TL 1000R but now I´m not sure. Good luck. Back-firing, to me, sound almost like a carb. pressure problem or something.???.