XRstroker, The XR200 is a great casual machine. You would be money and time ahead to just make the transition to a larger bike. These machines hold a very good resale, usually much better when stock. Being you are already tall enough, you might as well get a front disc brake, better suspension, more ground clearance, etc. Making the motor faster is only one aspect, you still have the rest of the chassis that will hold you back. Sounds like your ready to graduate to a new level of performance.