I just got a 2002 400ex, and I am thinking about getting the White Brothers e-series complete pipe, after looking at the June edition of ATV Sport. But I am also wanting to know some HAVE to do mods!! I am planning on racing MX, but i dont want to go to extreme. So any help would be appreciated, thanks a lot.





2002 Honda 400ex (yellow)
-TAG X5 bars
-Fast Trekker rear tires

 

Assuming that you get a full WB exhaust, I would definately get a K and N Powerkit. That all includes and K and N filter as well as a dynojet jet kit. A new air intake, jet kit, and exhaust are all three good components especially if you are thinking about racing. All that is going to cost about $500. But that's not going to the extreme in my opinion. But if you start messing with other internal engine mods, you are taking a big risk on the reliablity factor. So be careful of that.

That's all I did to my 400ex except, I have an FMF pipe instead of a WB. I just bought the slip-on instead of the whole system. That's really all you need.

Another thing that you could do is go down a tooth in your front sprocket. I did not do that on mine, but I hear that it improves torgue at the low-end. One thing that I would stay away from is the WB rev kit. I heard a rumor that it strains the 400ex engine with the extra 1000 rpm's produced on the motor.

As for body work, I would definately invest in a set of nerf bars as well as a full body skid and swing-arm skid. A-arm skids are not really that important in my opinion unless you do a lot of riding through the woods and trails. An alloy front bumper always looks nice on a 400ex and makes it easier to pick up the front end rather then having to pick up the stock front bumper. If you deside to race MX, you will definately need to invest in a tether switch (Pro Design kill switch). I would also recommend a set of headlight covers so you don't get a busted headlight from roost coming towards you on the track. And of course a set of number plates.

I know that it all sounds like a lot which it is, but that is only a fraction of what all is available for racing MX. Such as tires, suspension, extended a-arms, wider axle, and several other things. It all adds up just like any other sport. Anyway, I hope that I helped you out.

 

If you don't want to invest in the complete exhaust system, you can take the stock headers and grind out the welds on the inside, which will increase exhaust gas flow. A friend was actually going to buy the complete pro-circuit system, and pro-circuit themselves actually told him that this was the way to go.

Just a suggestion.

 

Hey REDTEAM;

I have to disagree with Fourtracker. I raced the full GNCC and have spent so much money on my quad it is unbelievable and have bought several things I wish I hadn't. I Suggest NOT to by a "JET" kit or POWER UP kit. Yes buy a K&N or Uni filter and a prefilter, but as far as jets are concerned, Dyno-jets are a pain and I even broke the adapter easily. The quad is jetted rich from the factory anyway, so if you just put a filter and pipe on, you;ll find it starts easier and fouls plugs less. It may be a little lean but instead of buying a bunch of jets you don't need, buy Keihen jets from Honda or another dealer. Stock is 148 main, I have a fully modded race motor running 165 main / 45 pilot and stock needle raised one clip, so you won't even use all those jets. Buy a 150, 155 and 160 and maybe a 42 pilot and spend the rest on something else.


If you are running MX here are so must mods - can't race without them.
Pro-Design Kill switch
Nerf bars
I suggest some smaller rear tires (18" turfs) and possibly a 14 T front sprocket.
Once you get into it, make the quad handle first (front shocks and a-arms at the same time, extended axle).
Go slow with what you spend and remember momentum, once you can ride the limits of the quad, then start modifying, you are going to need plenty of money for entry fees and safety gear and look at what the fast guys are using.

The is a stock 400ex with turfs and a small sprocket that beat the 250R's in A-class at a local race...he was an exceptional rider...but it proves that it can be done.

Hope this helps, I wish someone would have sat down and told me this before this year, I wouldn't have any credit card debt!!!!!

Nick 426EX

 

Hey "RedTeam",
"FourTracker" sounds right on the button for what you want.
At least he and I see pretty much the same. The only "add on" I don't have and want are wheel spacers. I've only raced mine a couple times now, but seem to have a little trouble in the turns keeping the speed up and being smooth. Especially on off-camber turns. I figure engine mods will come when something wears out. I beleive in the old addage: "If it ain't broke, don't fix it!" So I figure mines competitive enough to have fun on.
Without having spent too much money on it. [img]i/expressions/face-icon-small-cool.gif[/img]