Ha!! My first VC Mustang had a piston you could wobble inside the barrel and it still ran and cut people's grass. You had to rev it at ludicrous levels and use the momentum from the flywheel to do the work. It sounded like an air raid siren at full cry.
I ended up selling it to a mower shop for spare parts and got $20 for it during the 1990s.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!