12/05/2025
Columbus 25 HP Cam stopper engine. Running very smooth today at our road tractor show 11-8-25, on propane. This is a hit & miss engine. When the flyball governor is satisfied, the mechanism it controls, stops the outer end of side shaft with the exhaust cam holding the exhaust valve open. It inhales & exhales through the exhaust system allowing the piston to freely move through the four cycles. When the engine slows, the governor catches this, reconnects the mechanism allowing the exhaust valve to close. Fuel is drawn in and it fires again. It goes through this process over and over to control engine speed. This engine originally powered a machine shop line shaft. Today it has an easier life being displayed to the public and run on occasion.