BUOY 1395-9293 REC1395-9594

Function and technical context

The float is an essential floating component in the cooling and circulation system of Mercury, Mariner and Mercruiser engines. Its main function is to regulate the flow of coolant within the engine block, acting as a float valve that opens and closes according to the thermal circulation needs of the engine. This component works integrated into the freshwater intake housing or secondary cooling circuits, ensuring that the engine maintains optimal operating temperatures during navigation. If the float fails or loses its buoyancy, the cooling system can collapse, causing engine overheating, damaged head gaskets, and serious cylinder failures.

When to replace this part?

It is advisable to replace the buoy when a loss of efficiency is observed in the thermal regulation of the engine, symptoms such as recurrent overheating even under normal navigation conditions, or when the part has visibly deteriorated due to corrosion or water ingress into its hollow structure. It is recommended to check the condition of the buoy during each seasonal maintenance, especially before starting the navigation season, since the accumulated wear in cooling systems is silent but progressive. Replacing this part preventively avoids costly repairs resulting from overheating, such as complete replacement of head gaskets or offshore engine block repairs.

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers