As I stated in an earlier topic on cdi boxes, I found out from the local dealer that a xr250 cdi worked great on a 400ex, increasing the rev limit 1000 and advancing the timing. They sold so many they were on back order. Well, I finally got mine. I paid $85 for it. I also got some other accessories
to put on this past weekend but I decided to just put the box on first and try. The connections are the same, but the new box is a little shorter, so I had to come up with a spacer. I could definitly tell a differance on top end, works great! Saves money. I then installed a white bros. e series, K&N with outerwears,vented airbox lid,160 main jet, plus other necessities such as AC nerfs, motion pro twist, and a few other nic nacs. It runs great. I was taking it up and down the road(not reccomended so dont sue me if your caught), testing for misses or flat spots, and I couldn't keep the front tires on the road in 2nd gear after taking off full throttle, even sitting on the gas tank.
I love it! The pipe is a little louder than I expected though, oh well, who cares. If anyone needs the part number for the cdi let me know.

 

what is the part#, and how is the fit and finish on the AC nerfs? did you have to cut, bend, file, or wish them to fit? intrested please let me know.
ron

 

Hey Ron, I've got AC nerf bars on my 400 and I love them. it did take a little to get them installed though. I had to bend them a little and you have to drill a hole in your footpeg for installation but they look awesome and work great. Get them!

Good luck

 

I installed some DG Alloy Nerfs' - they were great - no grinding or bending anything - just bolt on - installed in less than 15min.

 

Do you have problems with sticks and other debris snagging on the netting when riding in the woods? Also, what about backing up with a set of nerfs on? Do you have to get completely off the quad or can you still straddle it and push from the seat?

 

I got the AC racing Pro pegs for my 2000 400ex. I love them, fit great, solid, etc... This is my 5th quad and I never had nerfs before, but these are great!!

 

The part # for the cdi mentioned above is
30410-KCE-671.
I didn't have any problem putting on my nerfs, just had to drill two holes, fit perfect.