KDXRIDER.NET

My 1992 Kdx is CA plated I love the thing and I use it for dual sport riding, tight single track, Motocross, around town, to school pretty much every type of riding, and it does them all well from my perspective except for one major flaw the death wobble. If I get on the track and at hit a small bump on a straightaway the front end will be uncontrollable. The front section will flail left to right like its got a mind of its own until I can fight it off and keep riding. Its kind of a confidence killer this happens in the desert too when I get on some hard packed bumpy stuff. My front wheel is not straight its got a fair amount of side to side and up and down movement, could that be it? Maybe a steering stabalizer? or longer forks? I need fork seals anyway cause I blew them bottoming out on a jump so forks wouldnt be a bad investment. Im happy with any fix to make this thing better on the track as long as I dont have to sacrifice my bikes great handling. Also if it helps I weigh 115lbs and my suspensions setup at the softest setting (I usually never bottom out so it works well)

Small bump should not be death wobble time. I would bring every thing (wheel shape, bearings, steering head bearings, seals and oil) up to stock and see what that does for you. I also would consider leaving your suspension setting close to stock, maybe a few clicks softer, but not all the way in, especially for MX.
New forks and a steering dampener would be an improvement for fast desert riding, but your bike shouldn't be uncontrollable in stock condition unless you are hitting rocks and ruts at high speed. Small bumps shouldn't cause loss of control.

How many riding hours do the forks and shock have on them?

Do you have the stock fork springs?

They are completely stock and un rebuilt original forks I beleive they have 7-10 thousand miles on them

Wow. You might want to rebuild the forks and shocks, with new wear parts and a very thorough investigation of the various parts. With fresh parts and oil, ride it again, then re-evaluate your needs.

I edited your title (and everyone else's) to say "motocross". Please don't say "motorcross".

Service the Forks for gosh sakes.

Forks and probably wheel bearings too.

yeah I checked my wheel bearings and it moved left and right only to be stopped by the brake caliper so looks like ill be hunting for wheel bearings a front rotor fork seals and probably a new rim, maybe do a kx 125 front end conversion. Has anyone had experience with this Im curious if it will mess with the way the kdx handles

It would be a good time for it. The new forks might need a rebuild and fresh oil as well. (same for wheel bearings and rotor)

There’s a multitude of topics about front end conversions. Read to your heart’s content.

I can tell you exactly what it is and surprised nobody mentioned it, at 115lbs the rear is too stiff for you and it upsets the front. mine used to do the same thing, I would be riding up a hill at speed then the front end would shake and I would fall off. I devised a simple test after to check the suspension settings, I would find a big speed bump in my local area then hit it at speed, when the rear does not match with the front you can feel the handlebars shake, if you go through my posts I did a write up for lighter riders

After re reading your post again I should mention that the rear may not be the only reason although it's the primary reason, the rebound on your forks may be too stiff. Again all written up in my post

thanks for the advice, I think read the correct post, you solved it by building a pvc spacer? how many mm in length was it?

I dont have a lot of knowledge about suspension

tommypx1 wrote: ↑12:05 am Apr 02 2020 thanks for the advice, I think read the correct post, you solved it by building a pvc spacer? how many mm in length was it?

Must be incorrect post. I don't know anything about a pvc spacer

I put several sizes of 1" PVC schedule 40 as a spacer - anywhere from 2" to 5" or so. I ended up replacing the springs on the stock forks, then I ended up replacing the forks with KX500 forks.