I am looking to to modify my quad some more. I have around 500 dollars to spend. right now i have upped the main jet, white bros. slip on, and holes in the airbox lid. i thought about a 440 kit but i'm not sure about that. other than the kits what else is out there? what are the benefits of changing cams and what are the different ones they offer? i'm satisfied with the suspension and the tires are still pretty good. i think i will get the rev kit though(what are your opinions on that).

I do not want to decrease reliability!

What are you mods on your 400's?

thanks for tips and info!

Jera '00 400ex

 

try a y scope piston all you have to do different is run a different octain. <marquee> hope this helps</marquee>

 

Wiseco?

 

I have the WB rev kit on my 400, bought it from CT it was $85. I am not sure but I think it might be a XR400 black box. It is the same brand as the original just about 2 inches smaller. I really dont think White Brothers had anything to do with the design or manufacturing of this product.

With that said I feel it helped my machine. I put a Sparks exhaust, air filter, and jet kit on my machine a week or two before the rev kit came and it seemed to help performance a little bit more. With a higher flowing exhaust you should be able to rev higher than stock. I know the 400EX makes stock peak hp at like 7700, but there still is a need to rev past peak hp, for example if you are attacking a steep hill where you might lose some revs as you go up it you might want to be revved up a little more to overcome it. Anyway, it is a inexpensive mod, and easy to put on it takes about 1 minute. It is located in a harness under your headlights, and plugs right in place of the original.

Adam Smith
99 400EX

 

I put a 11-1 wiseco k&n filter drilled lid powercore IV 160 jet. The 400 comes on a hell of a lot better. Wiseco is the way to go
dont bore it unless you have to. The WB CDI
box would be another good investment.