464 South Fifth St. Sebewaing, Michigan 48759
I was visiting with a fellow exhibitor at a gas engine and tractor show watching one of his engines running, when there was a loud bang, and the engine stopped dead.
When we looked the engine over we found a worn cotter pin, washer, and spring laying on the ground. It was from the intake valve. The vacuum in the cylinder sucked the valve into the cylinder!
The man took the head off and there laid the intake valve. The valve stem looked like a pretzel and it also bent the exhaust valve head.
I'd like to offer this tip to everyone in gas engine land. Check those cotter pins in your engines. Also check the intake and exhaust valves. If your engine has a threaded valve stem, check the jam nut and make sure it's tight.