I am sure the 07 WR450 is a great bike but posts about jetting has me wondering. My belief is a lot of folks are jetting way to rich. It can't be drastically different than my 06. I feel sorry for newbie jetting mechanics so I'll give my scoop until someone like Indy comes up with perhaps a new jetting chart for newer WRs, that is if the 07 jetting is actually different. Caution, I don't have an 07 so I don't really know. AIS removal does not require re-jetting. Not even doing the free mods does necessarily. Maybe a pipe would. New bikes run a little hotter at first because they're tight so don't idle them around. I'm running a 40 pilot jet (because I have ACV deactivated) - 2 turns, JD red #5, 168 main, 70 starter jet, 100 MAJ and 0 leak jet (BK mod: .2-.3 second squirt). Temperature is 45 deg F and altitude is 3500 ft. My mods: All free mods, FMF titanium powercore (very free flowing muffler), FMF powerbomb header, YZ exhaust cam and 13/50 sprockets. My 18 year old son says it has never run better. It is a wee bit lean (pops 2 or 3 times on decel but this doesn't necessarily mean its lean with ACV deactivated) but will do better in warmer weather. It has instantaneous, scary throttle response and continues to jerk your arms out of socket as the engine revs......I can't keep the front wheel down 1st through 4th even with a bald rear tire. I'm not saying my bike is inevitably faster than Joe Blow's but I know its jetted right. So good luck to 07 owners in jetting your bike.