Buying a car/bike is easy, even if you are using a tourist visa, the problem is the insurance, most insurance companies just make insurance for persons with SSN.
When I visited the USA in 2008 I bought a car (not really a CAR, in fact it was a $800 beater) in New Hampshire and drove it to NY. At that time NH was the only state in the US who doesn´t require you to hire an insurance to ride or drive you car/bike.
Suzuki GN125 2005
- Uberlândia / MG - Brazil
You don't need to have a big bike to have a great adventure.