Yeah, the skates lack something rather important - *brakes*.
When I was a kid, I saw several similar-sized 2-cycle engines fitted to bicycles. Those rigs were usually friction-drive and were mounted over the front wheel. I just did a quick search and found an interesting update of that idea. Search "Revopower" and you'll find a small gas engine and chain drive mechanism - all sandwiched into the hub section of a 26" aluminum bicycle wheel. The gas tank fits into a standard water bottle bracket.
As kids we tested those motorized bikes. A man on our street worked on the first weed whackers and worked in his garge at home figuring out every manner of use for the little engines, including bicycles and scooters. He let us ride them all over the neighborhood to test them.
The engines mounted over the front tire on a bike wore the tire down rather quickly.