Sierra Water Jacket Gasket 18-2544-9, Replaces 321028, Fits Evinrude 50/55 HP Outboards, Pack of 2

The Sierra 18-2544-9 is a water jacket gasket sold as a pack of two, engineered to seal the water jacket cover on Evinrude 50/55 HP outboards. It is built to Sierra's quality standard using materials selected for consistent sealing performance and long service life in the marine cooling system. This gasket sits between the water jacket cover and the powerhead, maintaining a tight seal around the cooling passages so the engine's raw water circuit stays leak-free and the powerhead cools properly during operation.

Because it ships two to a pack, the 18-2544-9 covers a complete gasket replacement in one purchase, which is useful when servicing both sides of the water jacket or keeping a spare on hand for the next service interval. It directly replaces OEM part number 321028, so it installs as a drop-in equivalent during routine maintenance, cooling system service, or when troubleshooting an overheating or leaking outboard.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2544-9
• Product Type: Water Jacket Gasket
• Package Quantity: 2 gaskets per pack
• Fitment: Evinrude 50/55 HP outboards
• Replaces (OEM): 321028
• Weight: 0.41 pounds
• Material: Other
• Package Dimensions: 54.864 cm x 17.018 cm x 0.762 cm
• UPC: 808282162795

Fitment

• Evinrude 50/55 HP outboards

Replaces (OEM)

• 321028

Frequently Asked Questions

What does the Sierra 18-2544-9 water jacket gasket fit? The 18-2544-9 is designed to fit Evinrude 50/55 HP outboards, sealing the water jacket cover on the powerhead.

Is 18-2544-9 the same as OEM part 321028? Yes, Sierra part 18-2544-9 replaces OEM number 321028 and serves as a direct equivalent for that gasket.

How many gaskets come in a pack of the 18-2544-9? Two gaskets are included per pack, priced and sold as a single 2-pack unit.

How much does the 18-2544-9 gasket pack weigh? The pack weighs 0.41 pounds.

What is the 18-2544-9 gasket made of? Sierra lists the material for the 18-2544-9 water jacket gasket as Other, a composite gasket material suited to sealing cooling system components.

When would I need to replace this water jacket gasket? Replacement is typically needed when servicing the water jacket cover, addressing a coolant leak, or performing routine maintenance on the cooling passages of a 50/55 HP Evinrude outboard, where the 18-2544-9 seals the cover to the powerhead.

Does the 18-2544-9 include installation hardware? No, the package includes only the two water jacket gaskets; it does not include mounting bolts or additional hardware.

Can I use one 18-2544-9 pack for a full water jacket service? Since the pack contains two gaskets, one 18-2544-9 pack is enough to cover a standard water jacket cover replacement.

Is the Sierra 18-2544-9 an OEM or aftermarket part? The 18-2544-9 is a Sierra aftermarket gasket manufactured to replace OEM number 321028 on applicable Evinrude 50/55 HP outboards.

What engine application is the 18-2544-9 gasket designed for? It is designed for Evinrude 50/55 HP outboard engines, specifically sealing the water jacket cover in the cooling system.