IMPELLER 47-89982

Function and technical context

The impeller is the central component of the water cooling system of Mercury, Mariner and Mercruiser marine engines. This flexible rubber piece rotates inside the pump housing driven by the drive shaft, moving cooling water toward the engine block for heat removal. An impeller in poor condition drastically reduces coolant circulation, causing engine overheating, loss of power, accelerated internal corrosion and, in extreme cases, engine seizure. It is a consumable wear part exposed to erosion by salt water particles and material degradation.

When to replace this part?

The impellers must be inspected annually before the start of the navigation season and replaced preventively every 300-400 hours of operation or when cracks, deformation of the blades, loss of elasticity or coolant leaks through the water intake are detected. Symptoms of failure include progressive engine overheating, weak water flow through the cooling outlet or unfiltered salt water inlet. Preventive replacement is the most economical strategy to avoid emergency shutdowns and costly repairs at sea.

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers