There is a playground in a small neiborhood near us, that has one of those, and other old equipment. We used to take our youngest niece and nephew there, and they loved it, especially the merry-go -round.
Who was the first one to sit on it, legs straight out under the framing an lean back out flat while it was spinning…..and don’t you old guys tell me you didn’t do that when all the parks had them when we were kids…
You don't need a motor on it. Get a leaf blower - or better yet two - and sit down and hold it tangential to the seats and hang on, if you can. Those have all but disappeared from playgrounds around here.