Yamaha Anode Set 99999-03946-00. Overview. The Yamaha Anode Set 99999-03946-00 is a genuine original equipment manufacturer kit designed to protect your engine from corrosion caused by electrolysis in marine environments. These sacrificial anodes are engineered to absorb corrosive activity, helping preserve critical engine components such as the lower unit, brackets, and internal passages.. Exposure to saltwater, freshwater, and mixed conditions can lead to gradual corrosion over time. Replacing