If it is completely stock, it has a 3-speed semi-auto tranny and 2.5 hp.
It all depends on what you plan to do with the bike, but if you weigh more than 7 stone you will have to spend some cash to upgrade the suspension. If you plan on motard racing, rules don't allow the stock front drum brake (SEMRC), therefore you're looking at a complete front end swap. You will also have to a heavy-duty clutch, or at least a spring kit, or the tranny will eventually start slipping. As far as the motor, a basic hop-up is an 88cc kit, cam, carb, and exhaust....which will still only put you around 6 hp.
If you have an unlimited budget, Honda is certainly the way to go for both reliability and parts selection. Hope that helps...