Hi, I've seen a few posts from people with XR400's that "miss" or "choke out" at high revs but no solutions I have a 2008 XR400M that has this problem. I have recently done the "normal" carby mods - bigger main jet and shiimed up the needle. This has made resulted in better throttle response, more pulling power and smoother at crusing speeds, BUT, it still just "chokes out" (ie. stumbles and will not rev any highr) when I hit a certain RPM in any gear. I'm not convinced it's a fuelling issues, maybe electrical, or timing ? Has anyone here had this problem and solved it please ? Please reply if you have any first hand experience with this particular problem. Thanks,... Rick.