WI DMV rules are:
To clarify, do you drive a moped or a motorcycle?
A moped, sometimes called a motor scooter, is a motor vehicle capable of speeds not greater than 30 miles per hour with a 150-pound rider on a dry, level, hard surface with no wind.
The power source must be an integral part of the vehicle and there should be a seat for the operator. A vehicle's engine must meet the following standards, based on its features, to be considered a moped.
If the vehicle has an automatic transmission, the engine must be certified by the manufacturer at 50 cubic centimeters or less or an equivalent power unit. This applies to most newer models bought in the United States. If you have a question regarding whether your vehicle is a moped or motorcycle, please contact the Wisconsin Department of Motor Vehicles.
If the vehicle is equipped with fully operative pedals for propulsion by human power, the engine must be certified by the manufacturer at not more than 130 cubic centimeters or an equivalent power unit.
Any vehicle with a larger engine capacity is a motorcycle, regardless of its appearance. If you are unsure of the classification of your vehicle, check with your dealer or local DMV office.