Water Pump Impeller – Fits Johnson/Evinrude 1.2HP-6HP & 60HP (Replaces 387361, 763735, 777831)

$15.69

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Water Pump Impeller – Fits Johnson/Evinrude 1.2HP-6HP & 60HP (Replaces 387361, 763735, 777831) is backordered and will ship as soon as it is back in stock.

Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This aftermarket Water Pump Impeller fits Johnson/Evinrude 1.2HP, 2HP, 4HP, 6HP & 60HP outboard models, specifically covering 2-stroke engines from 1976–1990 and certain 60HP models. It is a critical component for maintaining engine cooling system performance by ensuring adequate water circulation.

This impeller is a direct replacement for Johnson/Evinrude part numbers 387361, 763735, and 777831, as well as Sierra 18-3090 and Mallory 9-45210.

Designed for direct OEM-equivalent installation.
Constructed from durable neoprene rubber with a brass hub.
Some packages include the necessary key pin (0321130) for installation.

Part Number Matrix

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

Brand	Part Number
Johnson/Evinrude	0387361
Johnson/Evinrude	387361
Johnson/Evinrude	0763735
Johnson/Evinrude	763735
Johnson/Evinrude	0777831
Johnson/Evinrude	777831
Sierra	18-3090
Mallory Marine	9-45210
GLM	89490
SEI Marine	96-399-02

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Johnson/Evinrude owners, please note the specific year ranges and gearcase types to ensure a perfect match.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
Johnson/Evinrude	All models	1.2HP	2-Stroke	1986–1990	387361
Johnson/Evinrude	All models	2HP	2-Stroke	1985–1990	387361
Johnson/Evinrude	All models (90° gearcase)	4HP	2-Stroke	1976–1980	387361
Johnson/Evinrude	All models	6HP	2-Stroke	1979	387361

Technical Specs

Product Type: Water Pump Impeller
Installation: OEM Replacement
Dimensions: Shaft Diameter: 11.2mm (0.44 in)
Overall Diameter: 38.8mm (1.53 in)
Height: 18.6mm (0.73 in)
Number of Blades: 6
Material: Neoprene rubber with brass insert
Weight: 33g (1.16 oz)
Other Technical Attributes: Includes key pin (0321130) with some packages

What’s in the Box

1 x Water Pump Impeller (387361)
1 x Lockwasher (for 60 HP models) (included with some packages)
1 x Key Pin (0321130) (included with some packages)

Installation Notes

Disconnect the spark plug leads and shift the outboard into neutral.
Remove the lower unit (gearcase) bolts and carefully lower the unit.
Unscrew the bolts on the water pump housing cover to access the impeller.
Note the rotational direction of the old impeller's blades before removing it.
Remove the old impeller, key, gaskets, and wear plate.
Clean the housing interior and plate surfaces of any debris or corrosion.
Install the new key, gaskets, and wear plate.
Slide the new impeller onto the driveshaft while turning the shaft clockwise to bed the vanes correctly.
Reinstall the water pump housing and tighten the bolts to the manufacturer's torque specifications.
Reattach the lower unit, ensuring the driveshaft and water tube align properly.
Once assembled, test the engine in water to confirm a steady stream from the tell-tale outlet.

Troubleshooting & FAQ

Does this fit my 4HP Johnson outboard?

This impeller fits 4HP Johnson/Evinrude models from 1976–1980 that have a 90° gearcase. It's critical to verify your engine's year and gearcase type before purchasing, as other 4HP models use a different part.

What are the signs of a failing water pump impeller?

Common signs include a weak, intermittent, or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, and a noticeable drop in performance. Upon inspection, a worn impeller will have cracked, brittle, or permanently bent blades.

How often should I replace my impeller?

For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1–2 years, depending on usage (e.g., hours run, saltwater vs. freshwater operation). Always replace it if the engine has overheated or if the boat has been stored for an extended period.

Is the key pin always included?

Package contents can vary by seller. While our goal is to provide a complete kit, we recommend checking the "What's in the Box" section for the specific package you are ordering. This impeller requires key pin 0321130.

My 60HP Evinrude isn't listed, will this fit?

This impeller is known to fit some 60HP models, but we lack a definitive year and model range. To ensure compatibility, you must cross-reference your existing impeller's OEM part number with the numbers in our Part Number Matrix (e.g., 387361, 763735).

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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