I just moved back to Reno, NV and need to rejet my '00 WR400. I am having difficulty starting the beast when it is hot. I am also getting some mild backfiring with my current set-up (when slowing down from higher speeds). Any of you WR experts have any recommendations for main jet, needle, clip position? Unfortunately I do not know what is currently in my bike but I can say that under my current settings I fouled a brand new plug on its 1st time out. However it was not wet - it was bone dry and covered with black carbon. Any help, advise, or starting point would be great. I already took my bike into the local dealer to have them tune-up, adjust valves, and re-jet but SURPRISE still having difficulties.