How do you make a homemade go cart engine?

To make a homemade go-kart engine, you can use a small gas engine, such as a 5-10 horsepower engine from a lawnmower or a similar source. First, secure the engine to the go-kart frame using sturdy mounts, ensuring it's aligned with the rear axle. Connect the throttle and kill switch for safety, and use a chain or belt to link the engine to the axle for propulsion. Finally, check all connections and test for functionality before taking it for a ride.