[culcune]

Like Redcrow wrote, you don't want to mess with the internals of these thumpers; first off, they tend to wake up after 500 or so miles, then it is usually carb and exhaust. Since the hub is common to old Honda xl185 and the likes, rear sprockets are common as dirt with dual sports, and those who change them for either street use report great changes. However, you will have to research what hub your bike uses. Otherwise, your countersprocket should be common to the xr250 like the enduros. That could help out with performance.