For the purpose of this article, the following terms shall have the meanings indicated:
Includes any self-propelled unregistered vehicle powered by other than human power, except automobiles, buses, farm tractors, motor trucks, snowmobiles and mopeds as those terms are defined by the Maine Revised Statutes, as amended. The term "motorized vehicle" shall specifically include, without limitation, those unregistered vehicles commonly known as "minibikes," "trail bikes," "go-carts" and "dirt bikes" and motorized bicycles, whether commercially manufactured or homemade.