Our tags describe motorcycles as a "A self propelled two wheeled motor vehicle with an engine larger than 50cc's".
Describe scooter as a "A two wheeled motorized vehicle with a cylinder volume less than 50cc"
Describe moped as a "A two wheeled motor vehicle which incorporates pedals similar to a bicycle as a component of it's final drive system."
Why are we using these descriptions?
I would argue that these are unusual distinctions. To my personal experience the term moped is used for any 2 wheeler with engine less than 50cc rather than scooter. Some scooters can have engine volume up to 600s. Also, the current description of moped sounds just wrong but I wouldn't trust myself a lot on it. I would argue that distinction between a moped and the other two is usually in the engine volume and legal requirements. I have seen manual transmission, tank between leg bikes that register as mopeds because of the engine volume (cf. kuba rx9). The distinction between scooter and motorcycle is much harder to define rigoruously in my opinion. Motorcycles can have automatic transmission and can have driveshaft final drive. I also haven't heared of any legal difference between a motorcycle and a scooter. Hence the rigorous distinction I would suggest would be "where the tank is located?". I must emphesize that I do not imply the only difference between a scooter and a motorcycle is where the tank is located but I do mean for taxidermic purposes it should be the distinction.