MERCURY ANODE 40HP YAMAHA 70-85HP

Function and technical context

The sacrificial anode is an essential component in the cathodic protection system of submerged or partially immersed marine engines. Made of a reactive alloy, it is mounted on the cylinder head or at strategic points on the engine block to protect metal surfaces against galvanic corrosion caused by prolonged contact with salt or brackish water. Its function is to preferentially oxidize instead of the iron, aluminum and copper of the engine, significantly extending the life of the internal components and preventing the formation of red rust that compromises the structural integrity and sealing of the gaskets.

When to replace this part?

The anode should be visually inspected at least once per boating season and replaced when it has lost 50 to 75% of its mass or exhibits deep corrosion and pitting. Symptoms of a depleted anode include accelerated rust on the cylinder head, rust spots on the engine block, and in extreme cases, small water leaks in protected areas. Preventive replacement is recommended at the beginning of each season if intensive use in salt water is expected, thus avoiding costly repairs due to internal corrosion that can render the engine unusable at sea.

Equivalent manufacturer part numbers