WATER PUMP BASE KIT 43055A4

Function and technical context

The water pump base kit is the structural and closure component of the marine cooling system, responsible for protecting and containing the impeller and internal passages that circulate seawater through the engine block. This part works within the cooling circuit of Mercury outboard motors from 30 to 125 hp, both in two-stroke and four-stroke versions, maintaining the necessary tightness to prevent leaks and the uncontrolled entry of salt water. A failure in the cover assembly can cause pressure loss in the system, sediment ingress and accelerated corrosion in the internal galleries, compromising cooling capacity and leading to engine overheating.

When to replace this part?

Wear of the pump base kit is manifested through visible water leaks in the closure area, changes in the pattern of water exit through the discharge pipe, or the presence of rust and corrosion on the surface of the assembly. It is recommended to check the condition of this component during each seasonal maintenance, especially after sailing in waters with high sediment content or after prolonged periods of non-use. Preventive replacement of this kit prevents costly breakdowns at sea and ensures the reliability of the cooling system throughout the sailing season.

Engine Compatibility

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers