IMPULSOR

Function and technical context

The impeller is the central component of the seawater pump responsible for pushing the cooling fluid through the cooling circuit of the outboard or inboard engine. Made of flexible rubber, its blades capture and move seawater from the cooling intake to the heat exchanger or cylinder head, maintaining the working temperature within safe operating ranges. A damaged or broken impeller drastically reduces cooling flow, causing engine overheating, loss of power and, in extreme cases, irreversible damage to cylinder heads, gaskets and cylinder liners. Therefore, it is one of the most critical maintenance parts on any boat with a seawater-cooled engine.

When to replace this part?

The most common symptoms of an impeller in poor condition are the absence or reduction of the jet of cooling water through the exhaust, overheating of the engine indicated by the temperature indicator or the thermal alarm beep, and the appearance of black rubber fragments in the cooling circuit. It is recommended to replace the impeller every 300-400 hours of navigation or, at least, every two seasons, regardless of its external appearance, since the rubber loses elasticity over time even if it does not present visible breaks. Replacing the impeller preventively during seasonal maintenance is the most effective measure to avoid failure due to overheating at sea.

Equivalent manufacturer part numbers