Water Pump Impeller – Fits Johnson/Evinrude OMC Sterndrive 100–454 HP (Replaces 777130, 379475)

$14.45 $23.00

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Water Pump Impeller – Fits Johnson/Evinrude OMC Sterndrive 100–454 HP (Replaces 777130, 379475) is backordered and will ship as soon as it is back in stock.

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Product Details

This aftermarket Water Pump Impeller – Fits Johnson/Evinrude OMC Sterndrive 100–454 HP is designed for heavy-duty applications in Johnson/Evinrude OMC Sterndrive engines from 1964–1986 (excluding Cobra drives). It ensures reliable cooling performance for a wide range of horsepower ratings.

It serves as a direct replacement for Johnson/Evinrude part numbers 777130 and 379475, and interchanges with Sierra 18-3086 and Mallory 9-45281.

Direct replacement installation requires no modifications.
Constructed from durable neoprene with a solid brass hub for corrosion resistance.
Engineered for heavy-duty water pump applications.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Johnson/Evinrude	777130
Johnson/Evinrude	379475
Sierra	18-3086
Mallory	9-45281

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Johnson/Evinrude OMC Sterndrive applications:

Model	Rated HP	Years	OEM Part No.	Notes
OMC Sterndrive	100	1972–1973	777130/379475	Heavy-duty water pump
OMC Sterndrive	110	1964	777130/379475	Heavy-duty water pump
OMC Sterndrive	120	1965–1967	777130/379475	Heavy-duty water pump
OMC Sterndrive	120	1968–1984	777130/379475
OMC Sterndrive	140	1973–1984	777130/379475
OMC Sterndrive	150	1964–1966	777130/379475
OMC Sterndrive	155	1967–1972	777130/379475
OMC Sterndrive	165	1972–1976	777130/379475
OMC Sterndrive	170	1974	777130/379475
OMC Sterndrive	175	1975–1977	777130/379475
OMC Sterndrive	185	1967–1968, 1978–1984	777130/379475
OMC Sterndrive	190	1974–1977	777130/379475
OMC Sterndrive	200	1966–1968, 1979–1984	777130/379475
OMC Sterndrive	210	1968–1972	777130/379475
OMC Sterndrive	215	1971	777130/379475
OMC Sterndrive	225	1972–1976, 1978	777130/379475
OMC Sterndrive	230	1975–1976, 1979–1981	777130/379475
OMC Sterndrive	235	1971, 1975–1977	777130/379475
OMC Sterndrive	240	1978	777130/379475
OMC Sterndrive	245	1972–1975	777130/379475
OMC Sterndrive	250	1970–1974, 1979	777130/379475
OMC Sterndrive	260	1975–1976, 1979–1984	777130/379475
OMC Sterndrive	305	1977–1978	777130/379475
OMC Sterndrive	350	1977–1978	777130/379475
OMC Sterndrive	454	1977	777130/379475

Technical Specs

Product Type: Water Pump Impeller
Installation: Direct Replacement
Housing Material: Neoprene with Brass Hub
Number of Blades: 6
Height: 25.01 mm
External Diameter: 109.65 mm
Internal Shaft Diameter: 20.87 mm
Weight: 130 g (0.29 lb)
Warranty: 1 Year (aftermarket)

What’s in the Box

1 x Water Pump Impeller (Replaces 777130/379475)

Installation Notes

Disconnect the battery and ensure the engine is cool.
Drain the cooling system to prevent spills.
Remove the lower unit or water pump housing cover to access the impeller.
Take note of the old impeller's blade orientation before removing it.
Remove the old impeller and any worn gaskets or seals.
Thoroughly clean the inside of the pump housing, inspecting for scoring or debris.
Apply a light coat of marine grease or soapy water to the inside of the housing and the new impeller.
Install the new impeller, turning the driveshaft clockwise to bend the blades into the correct position.
Reassemble the water pump housing with new gaskets as needed, ensuring bolts are torqued to spec.
Reinstall the lower unit, refill the cooling system, and reconnect the battery.
Start the engine and check for proper water flow and for any leaks.

Troubleshooting & FAQ

How do I know if my impeller needs replacing?

Common signs of a failing impeller include the engine overheating, a weak or non-existent water stream from the "tell-tale" outlet, or visible damage like cracks, tears, missing chunks, or stiff, brittle blades. It is best practice to inspect your impeller annually and replace it as a preventative maintenance item.

Will this fit my OMC Cobra drive?

No, this impeller is specifically designed for OMC Sterndrive models from 1964–1986. It is not compatible with OMC Cobra drives, which use a different water pump design.

What is the difference between this and the OEM part?

This aftermarket part is engineered to meet or exceed OEM specifications for fit, form, and function. It uses comparable high-quality materials, including a robust neoprene body and a corrosion-resistant brass hub, to ensure reliable, long-lasting performance in marine environments.

Can I install this myself?

Yes, replacing an impeller is a common maintenance task for individuals with mechanical experience and the correct tools. However, professional installation is always recommended to ensure proper seating and functionality, preventing potential engine damage from incorrect installation.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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