2004 kx250 front suspension

Hey everyone,

I am trying to figure out the best way to make my front suspension less harsh off the initial part of the stroke. I am 160lb B class hare scramble racer. I went from stock springs to .40 front and 4.7 rear. I have it revalved by C-Cycle (pretty well known in the northeast) for woods but its still harsh for the initial part. I feel like it bounces over the rocks and square edge bumps. It has the stock amount of oil in the forks. Should I take out 25 or 50 cc's from each leg, or should I have it revalved rediculously plush. I am bottoming out like once per race so it uses most of the travel. I just don't want to take too much oil out or go too soft and bottom out a lot.

The rear shock feels great though so I'm just narrowing down the front.



I would leave the oil level where it is right now and play with your compression and rebound clicker settings. Write down where they are at right now and adjust them till you find the sweet spot. Than write those numbers down as well. If you remove oil, you will bottom out even faster.

Do you know how to work on your own forks, revalve, etc?  The springs sound pretty light.  I'd run the stock springs with a light 2 stage setup.

I know how to tear apart forks and replace seals etc. Never worked on the valving stacks. I have played with compression and rebound. I am going to go all the way soft with compression for next ride and see if that helps. I used to have a massive oil leak in both forks and went a while before i replaced it and had it rebuilt and revalved again. I always joked saying that the more i ride the better the suspension felt since more leaked out. So thats why i was considering lowering the fork oil height. But yea i will try to turn the clickers all the way out. they are at 13 compression, 11 rebound right now.

I have the same forks on my 125.  Revalving the base valve (comp) is easy.  (thanks Ed) Just put the bike on it's side with the end of the fork tube up so fluid doesn't run out, compress the fork a little with a strap and zip off the base valve using a 14mm allen on an impact gun.  Since they were already revalved the nut staking has been removed which makes it even easier.  


Remove the nut from the base valve and start removing the components of the valve keeping them in order.  Use a micrometer to measure each shim both thickness and diameter and post up the results.


My 125 forks are stock except I removed the bladders (common modification to those forks) and removed 3 face shims.  



Edited by Jeekinz

Here's the base (compression) valve.  Under the nut is the check valve, that lets oil back through during rebound, then you have the piston, under the piston is the compression stack.



Wow, Thank you for that information. I will try to pull it apart this weekend. Should i try running the comp clickers all the way out first to see if its better, or should i just pull it apart and let you know what it is?


And I had the bladders removed too.

You could try running full soft.  If you like it, that just will confirm you need lighter valving.  I still think the .40's are too light though, you could be confusing harsh with being too soft.

i will put a zip tie on it and ride some rough trails to check what im using for travel. My brother has a 2005 ktm200EXC (or XC cant rememeber) but he has extremely soft and plush suspension. My lap times go down quite a bit when i ride his bike and i feel like that is too soft but you dont feel the rocks roots or square edge bumps. I do bottom it out so I would go up a spring rate or two for his bike, but ive always complained about harsh initial response on my bike. As soon as im hitting big rollers or bigger stuff my front end feels awesome. it goes through the stroke nicely. its just the small stuff that makes my bike feel like its not moving at all with me, which unfortunatly is 90% of the terrain in the north east.

measure the stack and post the results

Disable the bladder. The 04 forks can still be harsh even after a revalve due to the bladder. I havent disabled mine yet but plan to do so this winter. Im running a set of 03 KX forks which are bladderless on my 04. They work much better than the 04s for offroad use. There is a old thread here somewhere on how to disable the bladder.

My bladders are removed. Ill do the shim stack this weekend. Can you easily get new shims from a dealer?

And jeekinz, where did you get those graphics. I love them.

Yeah, it's just as easy to completely remove the bladders, less parts, cleaner setup.  It's pretty straight forward, just remove all the pieces associated with them. To disable you just remove the white sealing ring.


You can buy shims from suspension shops.  Race Tech, Suspension Direct, etc. Here's some:  http://www.mei-inc.com/machine/shim/


The main thing is to measure and record what you have now.  That way you can always put it back to that setting.  And in case you drop a stack on the floor.  lol  


I had the graphics made at EVO-MX



Counting down days until the weekend!!


Stupid question, but are both sides the same stack or do i need to take both apart.


And those graphics are so sick. I like the 98 kx race graphics too on that site.

Both forks are the same. Evo-mx is a great company and is down with the older bikes, unlike n-style, et al.

I'm blowing the dust off this thread and my 04 kx250!!! I finally got it all together last night. I talked to a suspension guy from Iowa a few weeks ago who used to own an 04 KX and he told me to measure the stack and if I had 12 shims, and two large ones that were the same size as the first two shims, to take one out.

While taking that shim out I also took a measurement of thickness. I unfortunately didn't take the width if you guys need a width too, but you were right that it is super easy to take it apart and I'm more than willing to take them apart if need be. I took a picture with the sizes where the right is the top of the stack and left is the bottom. I had a really cheap micrometer that didn't go all the way down to ten thousandths but I hope this will give you a clue if I should do another valving on the bike.




Measuring the width was important.  The width affects the valving.


Were you ever in school and put a 12" ruler over the side of the desk and hit it with your hand to make it flop back and forth?  Did you notice that the less it was over the edge (shorter), the less it moved?  It is the same deal for shims.

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