tcs

If you're serious, check your state's laws. Really, check the actual title/tag/operator's license/insurance/inspection/emission laws in your state. Don't ask your buddy or your neighbor or the local policeman or the company's web site or the salesperson or your preacher/priest/rabbi/imam. Even if a neighbor is already operating one in some fashion, you could find out the law requires otherwise - after you get into an accident, to your financial peril. The local laws for small displacement motorbikes/mopeds/motorscooters/bicycles-with-engines are typically obscure and vary wildly, plus there are federal laws that also apply and chances are even folks who should know the requirements don't. In the USA a great many of such machines are sold illegally for street use and operated outside the law.

HTH,
tcs

PS - If you really needed/want power, the laws governing the operation of electric asist bicycles are generally far less onerous than those covering small displacement motorbikes/mopeds/motorscooters/bicycles-with-engines.