As used in this article, the following terms shall have the meanings indicated:
An engine-driven device which has a net weight of 900 pounds or less, which is originally manufactured with a width of 50 inches or less, which is equipped with a seat designed to be straddled by the operator, and which is designed by the manufacturer to travel on three or more low-pressure tires.
Designed to be used primarily off highway and was originally manufactured and otherwise complies with the regulations stated in W.S.A. s. 23.33(1)(ng).