Sierra 18-0965 Adapter Outer Powerhead Gasket, Replaces 331598, Evinrude Outboard

The Sierra 18-0965 is an Adapter Outer Powerhead Gasket engineered as a direct replacement for Evinrude outboard powerheads. This gasket seals the adapter-to-powerhead joint, helping maintain proper compression and preventing leaks at this critical connection point. Built to meet or exceed original equipment quality standards, it is designed as a drop-in replacement for the OEM number it references, making it a straightforward choice when servicing or rebuilding an Evinrude outboard powerhead. The gasket is finished in white and is supplied one per package, matching the original equipment quantity for this application. Because gaskets are wear items that lose their sealing ability over time from heat cycling and compression set, replacing the adapter outer powerhead gasket during any powerhead service or teardown helps restore a proper seal and reduce the risk of leaks or lost compression after reassembly. At 0.3 pounds, it ships and installs easily alongside other gasket set components during a routine powerhead rebuild.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-0965
• Product Type: Adapter Outer Powerhead Gasket
• Application: Evinrude Outboard
• Color: White
• Weight: 0.3 pounds
• Quantity per Package: 1
• UPC: 030999752048

Fitment

• Evinrude outboard powerheads

Replaces (OEM)

• 331598

Frequently Asked Questions

What is the Sierra 18-0965 used for? It is an Adapter Outer Powerhead Gasket that seals the adapter-to-powerhead joint on Evinrude outboard powerheads, part number 18-0965.

Does the 18-0965 gasket fit Evinrude outboards? Yes, the Sierra 18-0965 Adapter Outer Powerhead Gasket is built for Evinrude outboard powerhead applications.

What OEM part number does the Sierra 18-0965 replace? The 18-0965 replaces OEM number 331598.

How much does the Sierra 18-0965 gasket weigh? The Adapter Outer Powerhead Gasket 18-0965 weighs 0.3 pounds.

What color is the Sierra 18-0965 gasket? The 18-0965 Adapter Outer Powerhead Gasket is white.

How many gaskets come in one package of the 18-0965? One gasket is included per package for part number 18-0965.

Is the Sierra 18-0965 genuine OEM or aftermarket? The 18-0965 is an aftermarket Sierra part manufactured to meet or exceed the quality of the original equipment gasket it replaces.

When should I replace the adapter outer powerhead gasket? Replace the 18-0965 gasket any time the powerhead is disassembled for service, since gaskets should not be reused once a joint has been broken.

Will the Sierra 18-0965 seal properly against the original equipment part? Yes, the 18-0965 is designed as a direct-fit replacement for OEM number 331598 and is built to seal the same adapter-to-powerhead joint.

What is included when I order the Sierra 18-0965? Ordering the 18-0965 includes the Adapter Outer Powerhead Gasket itself, one per package.