Definitely check with a consumer credit lawyer on this one.

I believe that since you are doing a motor vehicle purchase the purchasers right to rescind the contract is only available to them if they are within a 72 hour period and they paid through a consumer credit card. Since you are doing motor cycle sales, this is still an option for the consumer because typically motorcycles, especially used ones can be paid in full by credit card. However, if they were to pay via a loan or cash, once signed the contract is legally binding.

Alternatively, there potential risks, such as the federal lemon law. You can find more information by calling 1-800-LEMON-LAW. Here is a list of all states that have the lemon law and which of them include motorcycle sales.

http://www.lemonlaw.com/automobile-lemon-law.html