The 1992 - 2001 CR 250's hit hard. This is partialy due to the powewrvalve set-up. The powervalve open's too quickly. This attribute's to a hard hit at around 6000 RPM when the powervalve opens. One of the best ways to make the CR250 more rideable is to install a Moose Racing power valve adjuster. It costs around $90.00 . It is a spring loaded mechanism that keeps the powervalve closed longer due to the preload the spring puts on the powervalve. Once the powervalve opens it will also open slower and this make for a smoother hit.
Also if the head has been Moded for race fuel, you might want to ceotact Cometic gasket company and get a 1mm thick head gasket to lower the compression ratio. This will also cool the hit. Hope this helps. ---Pete.