getting a 400ex race ready

[71_400TRX]

wht is there i can do to my somewhat stock 400ex with a uni filter and modified air box ( it is un jetted however, wht size would be reccomended for a uni filter and modified airbox with three holes drilled in the lid) anyone stiffen the preload on the front shocks, or is the stock setting fine, what r the pros and cons of having nerf bars without heel guards. any help or pics of ur 400s that u race would be cool. thanks

[250xridamatt]

What kind of racing will you be doing? That is the main thing that has to be known if you want much assistance.

[PowerJunkie]

mx im thinking.

[ingleful]

if u buy the K&N Air Box lid it comes with thte right jet u should be running in ur quad..i think..pretty shure mine did.

[miller821]

I would slap a Slip-On, or a Full System onto it, and jet it. As for nerf bars- The ones with heel guards work pretty great, but you can buy some without and still use your stock heel guards.You could cut your fenders, or buy race cut ones.Buy some holeshot's or razr's. That's about it, but thats the easy stuff that you don't have to go into the motor or nothing. Also a Kill Switch is needed in most places.

[ingleful]

buy 18 inch kenda klaws for the back and 21 inch Kenda dominators up front..dats what i run on mine..:D ...also go for the yoshimura comp full system!

[PowerJunkie]

what all do you have and done to your quad? just the filter, lid and jetted?

[71_400TRX]

i do mx, and alls ive done is a uni filter, drilled holes in the lid, and race cut my front fenders. i havent jetted it yet

[Aztrx400]

Ok so maybe another dumb question:confused:

Why race cut the fenders? What advantage is there to this?

[miller821]

Originally posted by Aztrx400
Ok so maybe another dumb question:confused:

Why race cut the fenders? What advantage is there to this?
Looks for one, also its not as flappy when mud gets on it, and also some people like to see there tires, knowing that have more control that way.

[Aztrx400]

Ok not as dumb as i thought,

If seeing your tires makes you think you have more control, then think again, I ride in rough desert terrain here in AZ. looking down at your tires means, your getting off the bike soon!!.

I ride looking way in front of where I am, and where i will soon be.

Here you have to be way ahead of what is going on, by not doing so means you and the bike will ultimatly meet, somewhere where it is uncomfortable, always for the rider not the bike.

[Rancher2005]

when i bought my 400 used the front shocks were on the 4th preload setting. Although i haven't used anything other than this it seems to work very well as it isn't too harsh. Keep in mind that im 245lbs and i havent bottomed them out yet. In my opinion, jetting is a must. Mine just didn't run right with the UNI and i have the airbox lid on!

[PowerJunkie]

how much money can you put into it to make it race ready? thats pretty much the most important Q

[dr.paine]

haha i agree, if you are controlling your quad by looking at your front tires after you cut your fenders, youre deffinately gonna be getting off your quad real soon :P

i shaved mine and i didnt gain any advantage other that it looks cool.

the only other reason i could maybe see a mx'er shaving their fenders is for less wind resistance, and maybe for a quick glance heading up the lip of a jump to make sure youre not going to hit some funky rut

[250xridamatt]

I have cut fenders, and they are basically pointless except for looking cool, especially with a wide front end like mine. Even if they werent cut, I would still be covered in mud.

[400eXr1d3rZ]

Originally posted by Aztrx400
Ok not as dumb as i thought,

If seeing your tires makes you think you have more control, then think again, I ride in rough desert terrain here in AZ. looking down at your tires means, your getting off the bike soon!!.


well you ride in the HOT im pretty sure you wear shorts right?? your gonna need the air to cool your legs down when you have a red hot engine under you

[PowerJunkie]

lol

[DieselBoy]

LOL!

[armysig]

What can you do to your 400ex to make it race ready. Great question!!! I can answer this since I'm doing it right now.

It depends on how much you want to spend on your quad. If you have a limited amount of funds you might want to consider basic upgrades first. Such as exhaust, jetting, and other small items.

But this is what I have done, and it's taken me 6 months so far to afford most of the mods.


Suspension cost for me so far is $1,900.00.

What I did so far.

American Star Racing A-arms - $470.00
Gforce Axle - $200.00
Elka front shocks off Ebay- $455.00
GT thunder shock service (valves and springs, front and stock rear and the GT thunder linkage. $645.00
Fasst Flexx handle bars - $200.00 used


Engine Mods completed or to be worked on soon. $580.00

Full LDR Pro 4 exhaust $400.00 off ebay new
Dynojet kit - $45.00 off ebay new
Hotcam stage 2 - $135.00 off ebay new

Work to be done soon $ 400.00? max?

Wesco piston 416 kit $100.00 (give or take a few $'s)
Bore the sleeve $100.00 to $250.00 depending on who does it.


First thing I worked on was the suspension, and then work your way into the engine. Others will say different, but I think you get better performance out of you quad if you can ride it with a good suspension. You won't believe the difference in the handling compaired to stock.

You can budget shop off ebay or this site. You'll save some good cash, but remember it's USED. So you may not know how well maintained the item was. In general most of the people here take care of thier stuff.

[Franky G]

I put just about 8000$ in my 400EX to make it race ready!

[mudmann]

don't forget some BALLS!!

[DieselBoy]

Originally posted by Franky G
I put just about 8000$ in my 400EX to make it race ready!


:eek2:

[MXracer16]

Originally posted by Aztrx400
Ok not as dumb as i thought,

If seeing your tires makes you think you have more control, then think again, I ride in rough desert terrain here in AZ. looking down at your tires means, your getting off the bike soon!!.

I ride looking way in front of where I am, and where i will soon be.

Here you have to be way ahead of what is going on, by not doing so means you and the bike will ultimatly meet, somewhere where it is uncomfortable, always for the rider not the bike.

For desert racing yes, it is pointless. For MX however, it is helpful when your in the air to look down at the landing and spot it out. The fenders get in the way if there not cut.

[krt400ex]

Originally posted by Rancher2005
when i bought my 400 used the front shocks were on the 4th preload setting. Although i haven't used anything other than this it seems to work very well as it isn't too harsh. Keep in mind that im 245lbs and i havent bottomed them out yet. In my opinion, jetting is a must. Mine just didn't run right with the UNI and i have the airbox lid on!

I'm 185lbs and my pre-load is as firm as it will get. I bottom mine out alot. Buy a set of aftermarket a-arms ands front shocks before you do anything. power doesn't mean anything if you can't use it. A wider front end and better shocks will allow you to corner better, therefore you will be setting faster lap times. A few horses from a pipe won't get you as far.

[krt400ex]

Originally posted by Franky G
I put just about 8000$ in my 400EX to make it race ready!

Can you send us some pics????

[DOHC]

if u going to get serious into racing ur going to need motor work and more power in general