Hey there, just bought a 2007 400SM, seems to be a solid bike but it pops like a sumbitch on decel, and seems to have a dead spot in the lower RPMS, it has died once when disengaging the clutch and cutting throttle. Its clearly running QUITE lean, but it was allegedly rejetted for the exhaust, which is a White Brothers setup. Looks like a slip on, but not sure how to tell the difference since this is my first DRZ. Seems to have the core in place. Nobody seems to have posted much about white brothers pipes and jetting, so I'm here asking you guys. I'll continue to search in the mean time but hopefully one of you fine people can steer me in the right direction. My next step is to do the requisite airbox 3x3 mod, and thusly, rejet again, but I'm curious if theres something I can do in the mean time to rectify this? Previous owner doesn't know anything about it since it was all done before he got it. My best guess is it wasn't rejetted, but it seems to otherwise run pretty good, aside from the dead zone I sometimes encounter - something I'm sure will be fixed with the rejet.While I'm on the subject, I was told by a buddy that the JD jet kit is supposed to have a cross reference sheet for the various exhausts (both with and without the airbox mod) so you can figure out which jet to run. Now, admittedly I know NOTHING about carbs, prior to this I had a fuel injected bike and have long since believed that carbs run on voodoo magic - I'd like to change that. I've searched around but didn't find anything like he described - is he high on exhaust fumes here or is it real? It sure would make the rejet process a whole lot easier than playing guess the smell with jets!Thanks!