All you really need to make a 400 run good is a pipe with matching clutch kit from either HPD,Aaen,Hotseat or RcR.You MUST have the clutch kit matched to the pipe for good reasons.Oh yea a good air filter and proper jetting.Who ever you get the pipe from can tell you what jetting to run for your location.After that the fun starts because you can mod them to make unreal HP.

 

<div class="FTQUOTE"><begin quote>Originally posted by: sprinter10

alot of people just don't drive them right and keep teh cleaned out it has nutral so it isn't a hard thing to do if your riding in the trail you just have to do a lil burnout every once in awhile to clear it out.</end quote></div>

o yea i also have a K&N air filter but everything else is stock