400 ex

[ddfetters]

just got a new '02 400ex. I'm looking for ideas on upgrading the machine. i've order a DynoJet kit (stage II) and K&N filter....now looking for the right exhaust....any ideas out there? don't want to sound like a dumb*** - just want some helpful tips on getting my 400 into top performance......

[tprender]

This will tell you all the info that you want to know about exhausts. The WB e-series slip-on and the sparks are rated the best in most tests.

[ddfetters]

any tips on modifying my air filter box?

[tprender]

All of these people are cutting holes and and other things to the lid. I take a piece of sheet medal and put ontop of the frame where the airbox is with the lid off. Cut and bend the medal to fit around the frame tubes. This way it will give you the performance as if the lid is gone but water can't get into the airbox after it splashs off the plastic. Make sure that you have and Outerwear's cover on the filter.

[sly400ex]

take the lid off and rejet....do a search for "cheap modifications" on here, you'll find a lot of good info.

[RED121572]

I may get screamed at for saying this, but Ill say it anyway.. LOL

How much did you spend on that Jet Kit? 60-70-80 bucks? Whatever the price was, RETURN IT. In the kit, there are so many jets that you will NEVER need. Buy the jets individually as you go.
Unless you require a Jet Kit, which includes about four extra pilot jets, four needle jets the four "Not large enough Main Jets."


...Ok, Im done now. Let us know how your beast comes together!:D

[Texan32]

Work on your suspension FIRST!!!!!!!! Ask anyone here that has aftermarket suspension...they will all tell you they wish they had done that first! I do!!!!! Get some better shocks. You may not BE faster, but i guarantee you can RIDE faster

[ddfetters]

i've been thinking 'bout the suspension thing....any suggestions on getting a better aftermarket setup? what's good & not-good?

[Texan32]

just about anyhting you do is going to help. How much are you willing to spend? Just remember....to an exten, the more you spend, the better it will ride. First thing i would do is get a set of aftermarket shocks. They start at 350ish (Works) and go up to 1200+ (Axis). Go over to the suspension forum. There are hundreds of debates about what is best! Its your money. Spend it how you want. I really like me Elka's. But ANYTHING is going to be better than stock. I wasn't really a believer until i got my shocks. it blew my mind at how much more agressive i could ride with them!:macho

[ddfetters]

thanks for the tips tex....i'm going over to the suspension forum.....

[RED121572]

Exellent reply. Ive never done anything to my suspension. I recently rode my buddies 400 and beside a pipe, hes got triple rate works on the front.....my nipples got rock hard!! LOL

[allen400ex]

What pipe would be the best. Yoshi? what about white bros e series or big gun. I want something to add as much power as i can. I i get a pipe it's going ot be a full system

[RED121572]

You need to first find out where you want the most power. Do you want top end power or bottom end power. Once that decision is made, you then can research which pipe will give you the most performance in that particular power band.

Good luck and let us know what you decide.:D

Ive got a slip on E Series from White Brothers. Its a bottom to midrange pipe.