Originally posted by: macentyre
Well in my case I've done alot of little things that have boosted the heck out of my machine.

here's my 400ex mod list:

1. big gun complete race series exhaust
2. white brothers rev limiter
3. airbox lid with vent kit
4. rejetted carb with 158 main jet
5. jensson racing air scoop shrouds
6. DPR8Z spark plug (wide operating heat ranges prevent fouling from running too cool and pre-ignition from running too hot)
7. uni filter
8. rear itp holeshot 20x11x9 tires
9. renthal handle bars
10. dg nerf bars
11. PRM full body skids
12. PRM baja bumper
13. VP MR1 race fuel (Delivers up to 6% more power over pump gas)
14. took off the e-break because it never worked right and just takes up weight
15. k&n oil filter

That's all I've done and it really helps alot! I can keep up with any of my budy's no problem! I've been clocked at 70mph on the flats next to my budy's bronco and I still had half throttle in fifth...no joke.

Have fun, if you ever need parts cheap and want great service go to www.honda-yamaha.com

Thanks,
Joey Mac