ANODE 75-130HP ALUMINUM

Function and technical context

The aluminum anode is a sacrificial component that protects the metal parts of the Mercury engine against galvanic corrosion in a saline environment. Strategically installed in the cooling circuit or in areas exposed to seawater, the anode preferentially oxidizes before the noble metals of the engine block, thus avoiding structural degradation of cast iron, aluminum and stainless steel. Its function is critical in vessels that operate in salt water, where marine electrochemistry exponentially accelerates corrosion if there is no adequate cathodic protection. Without an anode in good condition, the engine suffers internal pitting, loss of tightness in joints and, in severe cases, water entering the combustion chamber.

When to replace this part?

Aluminum anodes degrade predictably and should be inspected at the end of each boating season; If it has a volume loss of more than 50% or is completely consumed, it must be replaced immediately. Marine corrosion is relentless: even if the engine operates without apparent symptoms, the absence of cathodic protection silently accelerates internal damage, potentially compromising engine reliability on long voyages. Preventatively replacing the anode before it is completely depleted is recommended practice by manufacturers and avoids costly engine block repairs at sea or in port.

Equivalent manufacturer part numbers