I bought an 07 klx250s back in the winter and have not posted much about it. I really like the little bike. It has plenty of power for me and I got it for riding on smaller trails and in the woods. It had a few mods before i got it, aftermarket exhaust, carb work and smaller front sprocket.
It has had two issues, one leaky front fork seals and the steering bearing problem that the pictures here are about. The bike still has less than 2,000 miles so I wouldn't think that these should be a problem but they have been.

Steering bearing.. I began to have problems while cornering on the pavement. I felt like I was having to put too much steering input and then all of the sudden the bars would "give" making cornering very unpredictable. It got progressively worse so I tore into the steering stem. I found the lower steering bearing to be in awful shape(less than 2,000 miles). I ended up cleaning and regreasing the bottom bearing to get to an upcoming ride but they will need to be replaced ASAP. It was a hassle to get the bars, instruments, triple tree etc. out of the way to check this so I'm not looking forward to doing it again. Here are some pics.

 

I too have a leaking fork seal (well its stopped for now). I noticed when I turn at slow speeds (like in the driveway) my steering squeaks just a little, was this a symptom for you?

 

When I did the fork seals there was some grime in there and also a small nick on the fork tube. I used some very fine sandpaper on the fork tube and replaced the fork seals and dust covers.
As far as wheel bearings I never heard any noise, just really strange steering, I've read a few other posts and it was described as feeling like the steering was sticking. I felt it at parking lot speed and and higher speed cornering.

 

I had the dealer re-grease the head bearings along with swingarm pivot and all the linkages from new before I picked up the bike. The factories are pretty stingy with the grease. Should be a first mod for everyone. Oh! And go easy with the jet washer.
Maintenance is everything with an offroad vehicle.

 

Yeah, careful the pressure washing. If you spray directly on these bearing areas the high pressure can penetrate the seals and then you have a mess if you don't take care of it right away. I think the steering head area is especially prone to it.

 

I was the third owner at 800 miles. I don't know what they did but I've only hand washed the mud off. Now I have had it buried in some Hatfield Mcoy mud puddles and some other WNC creek crossing but as far as I know it has not been pressure washed. But you'd think it could take a little dunk'n and not have to worry too much about it.

 

Good quality grease, and lots of it.