HP and powerband question

Hi, this is my first post here, so tell me if I say or do anything stupid. I would like to know about what kind of HP levels I might get out of a '99 RM250 engine, if I tune it for top end power. Without a big bore kit or serious porting, is 50hp possible? How narrow would the effective powerband become? It's for a custom sportbike, and I hope to get the thing under 200lbs, so I don't think low down torque will be too important. Also, has anyone ever heard of a tach being fitted to one of these engines?

Thanks,
Nick

Thanks, guys. If the thing works out well, though, I will probably want more power. I have a turbo from an old Yamaha 650 sitting in my closet, but somehow I don't think it would be a good idea for a two-stroke. Maybe I will have to reconsider boring it out.
Nick