Sierra Water Pump Kit with Housing 18-3378 for Evinrude 50 HP & 55 HP (1979-85), 60 HP (1980-85) Outboards

The Sierra Water Pump Kit 18-3378 is a complete outboard water pump kit that includes the housing, giving boaters everything needed to restore proper cooling flow to the powerhead in a single purchase. This kit is built for Evinrude 50 HP and 55 HP outboards from 1979-85 and Evinrude 60 HP outboards from 1980-85. A failing or worn water pump is one of the most common causes of outboard overheating, and because the pump housing itself wears over time along with the impeller, replacing both together as this kit does helps ensure a proper seal and full-rated water flow rather than reusing a worn housing with a new impeller. Installing a complete pump kit with housing is the recommended approach when the old housing shows any scoring, grooving, or wear from the impeller vanes, since a worn housing bore will shorten the life of even a brand-new impeller. This water pump kit is sold under Sierra part number 18-3378 and is intended as a direct fit for the listed Evinrude horsepower and year ranges. Always confirm your outboard's exact model and year against the fitment listed below before ordering, since Evinrude used different pump configurations across different production years.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3378
• Product Type: Water Pump Kit
• Includes Housing: Yes
• Fitment: Evinrude 50 HP (1979-85), 55 HP (1979-85), 60 HP (1980-85) outboards
• UPC: 030999753557
• Weight: 0.19 pounds

Fitment

• Evinrude 50 HP, 1979-85
• Evinrude 55 HP, 1979-85
• Evinrude 60 HP, 1980-85

Frequently Asked Questions

What does the Sierra 18-3378 water pump kit include? This kit includes the water pump housing along with the pump components, sold as Sierra part number 18-3378, so the housing does not need to be reused when the pump is rebuilt.

Which outboards does part number 18-3378 fit? The 18-3378 kit fits Evinrude 50 HP and 55 HP outboards built from 1979 to 1985, and Evinrude 60 HP outboards built from 1980 to 1985.

Is this the same as a basic impeller-only repair kit? No. Sierra 18-3378 is a pump kit with housing, meaning it replaces the full water pump body rather than just the impeller, which is a more complete repair than an impeller-only kit.

How much does the 18-3378 water pump kit weigh? The Sierra 18-3378 water pump kit weighs 0.19 pounds.

Why replace the pump housing instead of only the impeller? If the housing bore is worn, scored, or grooved from years of impeller contact, a new impeller alone will wear out quickly; the 18-3378 kit replaces the housing along with the pump to restore a proper sealing surface.

Will 18-3378 fit an Evinrude 60 HP from 1986 or later? No. The 18-3378 kit is fitted to Evinrude 60 HP outboards for the 1980-85 model years specifically; later 60 HP model years use a different Sierra part number.

Does 18-3378 fit Evinrude 50 HP models from 1986 onward? No. Part 18-3378 covers Evinrude 50 HP outboards for the 1979-85 model years; outboards outside that range require a different water pump kit.

Is Sierra 18-3378 a genuine OEM part or an aftermarket replacement? Sierra 18-3378 is a Sierra-branded replacement water pump kit manufactured to fit the listed Evinrude outboard applications.

What is the UPC for the Sierra 18-3378 water pump kit? The UPC for the Sierra 18-3378 water pump kit is 030999753557.

Can this kit be used on both Evinrude 50 HP and 55 HP engines? Yes, the 18-3378 kit is listed for both Evinrude 50 HP and 55 HP outboards built in the 1979-85 model years.