IM CLUELESS ABOUT WHAT TO BUY OR EVEN WHERE TO START TO MODIFY MY 2001 400EX RIGHT NOW I HAVE GRAYDON NERFS AND FRONT BUMPER AND RENTHALS, BUT AS FAR AS SHOCKS, A-ARMS, EXHAUST, TIRES,BEADLOCKRIMS OR NO BEADLOCK RIMS,THERE IS SO MUCH I HAVEN'T GOT A CLUE WHAT IS GOOD AND WHAT IS NOT..BUT I DON'T WANT TO INVEST IN STUFF THAT I DON'T REALLY NEED ALTHOUGH IT WOULD BE NICE. IM JUST GETTING BACK IN TO THE SPORT,FROM A FEW YEARS OF SPORT BIKES(MODIFIED1998 CBR900RR)AND MY SON JUST TURNED 1 AND ATVING CAN BE ALOT SAFER AND FAMILY ORIENTATED THAT STREETBIKES..(PRIOR QUAD WAS AN 1987 250X)IM JUST SCARED TO INVEST ALOT OF MONEY IN MY QUAD AND LOSE INTEREST IN IT A YEAR OR TWO DOWN THE LINE... SORRY THIS WAS SO LONG!!!!!!!!

 

If you are into just having fun then leave it stock. When you have the throttle pinned too much then you are ready for mods.

 

umm start with a pipe and jet kit.....humm whats good on the 400ex? DMC,Big Gun,and White Bros are some of the top ones.ummm some laeger +2" a-arms with some works shocks would be good. I dunno I could go on and on......what do you want first power or handling?

 

I'm not a sport quad rider yet but i would start with a pipe and jet kit. I've heard good things about the Big Gun pipe. After that I would leave the engine alone for a bit and focus on the suspension. The 400EX is an extreamly nimble quad in stock form, but everything can be improved.

 

get these parts in order, first get your timing advance key and fly wheel puller from sparkracing.com for $15. then go for pipes,airfilter,jetting package. then get a 440 kit if you want more power, if not get a-arms(+3or+2)maybe even a swingarm. Then TCS shocks, make sure it's a zero-preload shock and not a works set-up. check out my mods on my page.