Building My 400ex

[wakaa06]

I have a 99 400ex right now the motor is all stock except the piston with 10.1 comp ratio, full HMF exhaust, K&N Air filter, Lonestar back axle. I am wanting suggestions on what to do with it. I do alot of trail riding here in southeastern ohio around wayne.

[400exmxrider15]

Whats your budget? We can tell you many things that you cant afford....

[wakaa06]

I have around $600 to spend. I have a couple things I no i'm gonna get like a uni foam air filter

[vinnytobasco]

I would worry about suspension ,handling and braking befor power mods.So I would say 450r front shocks revalved and resrung for your weight, used extended a arms, steal braided brake lines , wave rotors and maby yfz450 calipers.Then if you have any money left over I would get a stage 2 hot cam .But thats just me, theres a ton of options don't rush it just look for good deals and get the best bang for your buck.

[CJM]

450r front shocks revalved by a reputable shop, JET, C&D, GT Thunder, etc. Gonna run you about 300-400 bucks but the quad will handle better and you can go faster. If you want to hold off you can just do the 450r shocks and run them stock-vast improvement over the EX shocks.

Revalve/respring rear shock, if you send it off to GT Thunder or contact JET they can rework the shock for your weight and you can get the XC or MX link (look at GT Thunders site). you have to either cut your skid out for the link or use GT Thunders skid-but this will totalyl fix the bucking issue the rear has over bumps.

Then Id spend on exhaust, either a bore or at least a higher compression piston like a 10:1, 6 degree sparks key, and a hotcam stage 1 or 2.

Bit more than you might want to spend overall. But doing the suspension first will make you faster b/c you arent fighting the quad anymore.