The Zeeter 311 was last made in the late 1980's It turns by braking(slowing down one wheel while speeding up the opposite wheel. Newer type mowers use hydraulic pumps and can reverse one wheel while speeding up the other. The Zeeter system works on smaller yards and at slower speeds. If you have a lot to cut and try to push it the friction brakes will cause trouble. I'm not sure if you can find replacement parts. Like Black Bart I would be concerned about the brakes and not the engine. You can find an engine.