I stand by that my klx250sf is stable to 90+ mph (downhill no wind) and even through a freeway curve with bumps...no wiggle...

 

I got the head shake wobble today at an indicated 80 mph. Prior to putting in the 351 kit the best I ever saw on the speedo was 75 so this was new for me. It got pretty bad at one point. I actually found sliding back on the seat helped. Regardless I'm going to look into the steering bearings and maybe take the rim lock off the front. Until then I'm going to try to keep it under 65. FWIW I've got an '07 S model with 13/42 gearing. That 351 is quite nice - at 80 mph (again, indicated) it was still pulling.

 

did that stabilizer cover the key hole?