The 98 KX 250 had a monster motor, The updated detent was actually a step backward, the fix was to use the previous years shift detent. Suspension is rider sensitive, so if your lighter you may be OK otherwise you may need heavier springs. The 06 has a killer mid range and up powerband, with very little bottom end, I don't like it but my son does. The best motor mod for the 97-02 250 is the Wiesco flat top piston mod, it totally enhances the power band, Tom Morgan did my head and it ripped. I think the 05 and newer would be my first choice, they have the twin chamber KYB's, and they work well.