ANODE SELVA S405-S700

Function and technical context

The sacrificial anode is the component responsible for protecting the submerged metal parts of the outboard motor against galvanic corrosion, an electrochemical process that progressively degrades the aluminum of the casing, the shaft and other metal elements in contact with water. Made of an alloy with a higher oxidation potential than the metals it protects, the anode acts as the negative electrode of the system, consuming itself to preserve the structural integrity of the engine. In Selva outboard motors from the S405 to S700 series, this component works directly in the submerged stern area, where exposure to salt, brackish or fresh water can cause pitting and material loss in components that are difficult to access and have high replacement costs. Without effective cathodic protection, corrosion progresses silently and can seriously compromise engine life.

When to replace this part?

The clearest sign that the anode must be replaced is the loss of between 50 and 70% of its visible mass: when it appears noticeably reduced, with a very irregular surface or practically consumed, it no longer offers sufficient protection. It is recommended to inspect the anode at each beaching or start of the season, and replace it preventively at least once a year in salty or saline waters, since a depleted anode leaves the engine's aluminum components exposed to accelerated corrosion that can lead to serious and costly breakdowns. Changing the anode promptly is one of the most economical maintenance interventions and has the greatest return in engine longevity.

Equivalent manufacturer part numbers