I just took the plunge on a 400ex (black) today . Just wondering now what I can do to "open" it up a little.
I had a 04' XR250R dirt bike and if I remember right . I removed a baffle or something from the stock silencer and changed the main jet .
Is there anyone out there that has gone this way and have a suggestions or answers ?
My wife let me get some DG nerfbars with heelguards but said I had to stop there for right now. So, I am looking for some cheap mods that work.
I can probably sneak in an aftermarket airfilter but would like to modify the stock exhaust as I won't be able to sneak this by.
Thanks,
D.

 

The VERY first thing to do on an EX is to adjust the throttle cable. For what ever reasons chosen by Honda, the throttle at full throttle isnt actually opening the slide fully because you used alot of the lever travel before it ever budged the cable. Remove this slack and it gives a NOTICEABLE difference in performance.

 

By the way, be sure you turn the handlebars both directions after adjusting the cable while the engine is running and BEFORE you put it in gear to be sure it's not adjusted to tight and that the steering doesnt tug at it.
Sometimes not doing so makes for some rather interesting cornering techniques. [img]i/expressions/face-icon-small-wink.gif[/img]

 

hmm thats weird KNOWSALOT. I got a friend with a new 400ex and i'll try that out and see if it goes any quicker.

 

Pull out your spark arrestor and pound a bigger hole in the baffle inside with a piece of pipe. put your s.a. back in. Remove airbox lid and rejet. If you want to spend a little money, have it ported $200-250. WEB Cam not a hot cam $140. JE 11:1 piston(can still run 94 octane) $150. And if you still want a little more snap after that, get a Lectron carb for it.

Dont bother buying a pipe for this machine. Honda did a very good job with this pipe. Look at any shootout, even the best pipes only gain 2-4 hp and thats all in removing the airbox lid and rejetting