I just bought a '01 400EX and have heard many of you talk about the throttle cable adjustment that has to be made on several of the '00 400 EX's what exactly do you have to adjust.

 

Read down the list under you find a post titled "2000 400EX Carb Question"...that topic pretty much answers your question. You can also search using "86atc250r" in the author search field...Gabe has often volunteered to email the procedure.