Water Pump Impeller – Fits Evinrude/Johnson 10-25 HP (Replaces OMC 375638, 0375638, 379766, 0379766, 382468, 0382468, 777518, 0777518, 777829, 0777829)
Water Pump Impeller – Fits Evinrude/Johnson 10-25 HP (Replaces OMC 375638, 0375638, 379766, 0379766, 382468, 0382468, 777518, 0777518, 777829, 0777829) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Impeller – Fits Evinrude/Johnson 10-25 HP (Replaces OMC ...
Product Details
This Water Pump Impeller – Fits Evinrude/Johnson 10-25 HP is a crucial replacement part for maintaining engine cooling in Evinrude/Johnson 10–25 HP 2-Stroke outboards from 1949 to 1978. It ensures your engine's water pump functions efficiently to prevent overheating.
This component is a direct interchange for OEM part numbers including OMC 375638, 0375638, 379766, 777518, and 777829, as well as aftermarket equivalents like Sierra 18-3002.
- Made from durable neoprene rubber and a corrosion-resistant metal alloy hub.
- Features a 6-blade design for optimal water flow.
- Lubricate with silicone grease, glycerine, or dish soap during installation for proper seating and performance.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| OMC | 375638 / 0375638 |
| OMC | 379766 / 0379766 |
| OMC | 382468 / 0382468 |
| OMC | 777518 / 0777518 |
| OMC | 777829 / 0777829 |
| Sierra | 18-3002 |
| MARKGOO | 775518 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
The following table lists compatible Evinrude/Johnson outboard motors.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Evinrude/Johnson | 10 HP | 10 | 2-Stroke | 1949–1957 | 375638, 775518 | |
| Evinrude/Johnson | 15 HP | 15 | 2-Stroke | 1953–1965 | 375638, 775518 | |
| Evinrude/Johnson | 18 HP | 18 | 2-Stroke | 1953–1965 | 375638, 775518 | |
| Evinrude/Johnson | 20 HP | 20 | 2-Stroke | 1966–1973 | 375638, 775518 | |
| Evinrude/Johnson | 25 HP | 25 | 2-Stroke | 1969–1978 | 375638, 775518 |
Technical Specs
- Product Type
- Water Pump Impeller
- Housing Material
- Neoprene rubber and metal alloy
- Height
- 6.0 in
- Width
- 7.13 in
- Length
- 0.5 in
- Hub Shaft Diameter
- 12.8 mm (0.50 in)
- Weight
- 39.7 g (1.4 ounces)
- Number of Blades
- 6
What’s in the Box
- 1 x Water Pump Impeller
Installation Notes
- Disconnect the spark plug wires and the battery for safety.
- Place the outboard gear shift in neutral.
- Remove the lower unit (gearcase) from the engine's driveshaft housing.
- Unbolt and remove the water pump housing cover.
- Note the rotational direction of the existing impeller blades before removal.
- Slide the old impeller off the driveshaft. A flathead screwdriver may be needed for leverage.
- Clean any debris or corrosion from the pump housing, wear plate, and driveshaft splines.
- Apply a liberal amount of silicone grease, glycerine, or dish soap to the interior of the housing and the new impeller.
- Slide the new impeller onto the driveshaft, twisting it in the direction of engine rotation to bend the blades correctly.
- Reinstall the water pump housing and torque bolts to manufacturer specifications.
- Reattach the lower unit to the engine.
- Reconnect spark plugs/battery, start the engine with a proper water supply, and verify a strong water stream from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if this impeller fits my engine?
First, check the compatibility table provided on this page. Verify that your engine's brand, model, horsepower, and year range are listed. For best results, cross-reference the OEM part number stamped on your existing impeller with the numbers in our Part Number Matrix.
What are the signs of a failing water pump impeller?
Common symptoms include the engine running hotter than normal (overheating), a weak or intermittent water stream from the engine's tell-tale outlet, or a complete lack of a water stream. If you notice any of these signs, inspect your impeller immediately.
How often should I replace my impeller?
As a general maintenance guideline, we recommend replacing your impeller every 1-2 years or every 100-200 hours of engine use. This interval can be shorter if you frequently operate in sandy, silty, or saltwater environments.
The new impeller's blades are straight, but my old one's were curved. Is it defective?
No, this is normal. Impeller blades are made of flexible neoprene. They are straight out of the box and will curve to the shape of the pump housing once installed and the engine spins. It's important to twist the impeller in the direction of engine rotation during installation to pre-bend the blades correctly.
What kind of lubricant is safe to use for installation?
Always use a lubricant that is safe for rubber and will not degrade the neoprene. We recommend a light coating of silicone grease, pure glycerine, or simple dish soap inside the pump housing and on the impeller.
Is this an OEM part or an aftermarket part?
This listing is for a high-quality aftermarket replacement part, not an OEM component. It is engineered to meet or exceed OEM-level specifications using comparable materials and is manufactured in an ISO 9002 certified facility with batch inspections for quality control.
What are your shipping speeds and costs?
We ship worldwide quickly, with typical transit times of 5–15 days for most regions. Standard shipping is free on all orders. Expedited shipping options, if available for your location, will be presented at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window, provided the part is unused and in its original condition. Please see our full policy page or contact us for return instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchase. If anything differs—even if your model appears on the compatibility list—do not purchase and contact us for support.
- This is an aftermarket replacement part, not an original equipment manufacturer (OEM) component.
- Professional installation is highly recommended for parts that affect engine safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with an average transit time of 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
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