Gasket 328618

Function and Technical Context

This gasket acts as a static sealing element between two surfaces of the outboard engine, preventing the passage of fluids—cooling water, oil, or gases—between cavities that must remain isolated. It is part of the sealing assembly of the block or engine head, being an essential component for maintaining the integrity of the cooling circuit and the correct operation of the propulsion unit. A failure in this seal can cause fluid mixing, loss of cooling, engine overheating, or water entry into critical areas, with the consequent risk of serious damage. Its design is specifically conceived to adapt to the contact surface geometry in Johnson and Evinrude engines of the corresponding series, as well as for compatible cross-reference numbers from Mercury, Mariner, and MerCruiser.

When to Replace This Part?

The most common symptoms of deterioration of a gasket of this type are the appearance of moisture or oil stains at the joints between heads and block, pressure loss in the cooling circuit, or signs of recurrent overheating with no apparent cause in the cooling system. It is recommended to inspect the condition of this gasket at each seasonal maintenance and replace it whenever the head or component on which it sits is disassembled, since static gaskets must not be reused after being compressed. Replacing it preventively during any engine work avoids progressive leaks that, if not addressed in time, can lead to costly damage away from port.

Compatible Johnson/Evinrude Engines

Equivalent Manufacturer References