BOARD 342513 REC342513

Function and Technical Context

This gasket acts as a sealing element between metal surfaces in the outboard motor, preventing the passage of fluids or gases between adjacent cavities. Its function is critical for maintaining the integrity of the circuit in which it is installed, whether in the cylinder head, the thermostat housing, the water pump, or any other joint where a hermetic seal is required. A poor seal causes coolant leaks, saltwater ingress into sensitive areas, or internal exhaust gas leaks, which can lead to engine overheating, accelerated corrosion of internal components, and severe damage to the engine block. Its proper installation is crucial to ensuring the performance and service life of the Johnson or Evinrude engine in which it is installed.

When should this part be replaced?

The most common signs of deterioration in a gasket of this type include the presence of moisture or corrosion spots in the joint area, loss of pressure in the cooling circuit, recurring overheating with no apparent cause in the cooling system, or the detection of bubbles in the coolant indicating a gas leak. It is recommended to inspect and replace this gasket every time the affected area is opened during seasonal maintenance, as reusing a previously compressed gasket compromises the assembly’s seal. Replacing it as a preventive measure when disassembling any adjacent component avoids having to repeat the procedure for a low-cost part and prevents major breakdowns while underway.

Compatible Johnson/Evinrude Engines

Equivalent Manufacturer Part Numbers