I read the posts but was so pleased with my power that I figured it was fine. I was clocked @ 70MPH on flat ground last weekend by a C-5 Vette with dual analog/digital speedometers. I felt the top end was flat but figured it was the stock pipe or closed intake box. I was busy loc-tighting bolts without yellow paint since some have fallen off already! I then decided to pull the air box and look at my throttle adjustment I held it open and looked down the carb and saw about a 1/4" of the slide sticking down and the butterfly was at about 15 degrees from flat. I adjusted it and reassembled. I will ride it tomorrow if I can find some time and a dry spell. I think a good way to check your bike is to pull back the rubber boot over the cable adjustment fttg. and see if there aren't any threads showing then it has not been adjusted. Mine was all the way in and the lever had a lot of play in it 3/4-1", the manual says @ 1/8" of play. Hope I can feel the difference. Good Luck!
Terry 00' 400EX

 

I HAD HEARD ABOUT THAT ALSO.I CHECKED MINE AND TO MY SHOCK,IT WAS ONLY OPENING ABOUT 70%!

 

Told ya so! Told ya so!

Hehe :P .... I was the one that originally posted this back in September, didn't believe me did you!

Enjoy your newly found HP, I did. The top end difference is substantial.

 

Hey look down on 400EX BEST MODS,I already complimented you !

Thanks

 

My '99 feels really strong. I don't think it is misadjusted, but has anyone had problems with '99 models?

 

Nope, from what I have seen, it is limited to the 2000 models.