Yanmar Aluminum Anode Kit ZT350 ZT370

Function and technical context

Aluminum sacrificial anodes are part of the marine engine's cathodic protection system, acting as a galvanically active element that corrodes in a controlled manner to preserve the internal metal components of the salt water cooling circuit. In Yanmar ZT350 and ZT370 engines, salt water continuously circulates through the block, cylinder head and heat exchangers, creating ideal conditions for galvanic corrosion that can irreparably damage the base metal. By progressively sacrificing, the high-purity aluminum anodes shift the electrochemical reaction toward themselves, protecting the engine block, coolant plugs, and cooling system passages. Without effective cathodic protection, galvanic corrosion can compromise the structural integrity of the engine within a few saltwater boating seasons.

When to replace this part?

The anodes should be inspected at least once a season and replaced when they show wear greater than 50% of their mass, or when they show signs of surface passivation that indicate loss of electrochemical activity. In engines that frequently sail in salty or brackish waters, it is recommended to check the condition of the kit at each stranding or annual maintenance, since a depleted anode leaves the metals of the cooling circuit exposed without any protection. Replacing the kit preventively at the beginning of each season is the practice recommended by marine mechanics workshops to avoid costly damage to the engine block or heat exchangers.

Engine Compatibility