Yamaha - Cylinder Head Anode Corrosion Protection 67F-11301-00-00 / 67F-11301-01-00. Overview. Corrosion protection inside a Yamaha outboard is something experienced boaters never ignore. The Yamaha Cylinder Head Anode 67F-11301-00-00 / 67F-11301-01-00 is designed to absorb electrolysis before it can attack the engine's internal metal surfaces. Instead of letting corrosion damage cooling passages and engine components, this anode sacrifices itself first. It's a small part, but it plays a big rol