MERCURY UPPER GASKET KIT 858732T02

Function and technical context

The upper gasket kit is a set of critical sealing elements that make up the tightness of the cylinder head and combustion chamber in Mercury four-stroke engines. These gaskets work in the cylinder head sealing system, preventing leaks of cooling water, lubrication oil and combustion gases between the block body and the cylinder head. A failure in these gaskets compromises the tightness of the engine, causing loss of coolant, entry of water into the crankcase, oil contamination and a decrease in the general performance of marine propulsion.

When to replace this part?

Head gaskets present characteristic symptoms such as visible coolant leaks around the gasket, engine overheating despite correct water levels, oil emulsion (milky appearance), loss of power and difficulty starting after periods of inactivity. It is recommended to replace this kit preventively every 5-8 years or after repairs that involve dismantling the cylinder head, regardless of the hours of operation. Replacing these gaskets preventively during scheduled maintenance avoids emergency repairs in navigation and prolongs the useful life of the engine block.

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers