Water Pump Impeller for Evinrude/Johnson Outboards 10–25 HP – Replaces OMC 375638, 389646, 775518 and 777829
Water Pump Impeller for Evinrude/Johnson Outboards 10–25 HP – Replaces OMC 375638, 389646, 775518 and 777829 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Water Pump Impeller for Evinrude/Johnson Outboards 10–25 HP – Repla...
Water Pump Impeller for Evinrude/Johnson Outboards 10–25 HP – Replaces OMC 375638, 389646, 775518 and 777829 is backordered and will ship as soon as it is back in stock.
Product Details
This is a replacement water pump impeller for selected Evinrude and Johnson outboard engines rated from 10 HP through 25 HP. Supplier-listed applications cover model years from 1949 through 1978, depending on horsepower. The impeller is sold as a single replacement component for restoring water-pump circulation and supporting the engine cooling system.
The supplier lists this impeller against the following Evinrude, Johnson, OMC and BRP Marine reference numbers: 0775518, 0375638, 0777829, 0389646, 775518, 375638, 777829 and 389646. The supplier also lists aftermarket cross-reference numbers from Mallory, Sierra, GLM, SEI and CEF. These references are provided for identification; confirm the exact engine model, year and existing impeller before ordering.
- Replacement water pump impeller for selected Evinrude and Johnson outboards.
- Supplier-listed horsepower range: 10 HP, 15 HP, 18 HP, 20 HP and 25 HP.
- Supplier-listed model-year coverage: 1949–1978, varying by horsepower.
- Single impeller only; key, gaskets, housing and other water-pump parts are not included unless separately stated.
- Aftermarket replacement component; not an original manufacturer-branded part.
Part Number Matrix
The following are supplier-listed OEM and aftermarket reference numbers. Use your engine identification and the dimensions of the original part to confirm compatibility.
| Brand or Reference | Part Number |
|---|---|
| Evinrude / Johnson / OMC / BRP Marine | 0775518 |
| Evinrude / Johnson / OMC / BRP Marine | 0375638 |
| Evinrude / Johnson / OMC / BRP Marine | 0777829 |
| Evinrude / Johnson / OMC / BRP Marine | 0389646 |
| Evinrude / Johnson / OMC / BRP Marine | 775518 |
| Evinrude / Johnson / OMC / BRP Marine | 375638 |
| Evinrude / Johnson / OMC / BRP Marine | 777829 |
| Evinrude / Johnson / OMC / BRP Marine | 389646 |
| Mallory Marine | 9-45215 |
| Sierra Marine | 18-3002 |
| GLM Marine | 89650 |
| SEI Marine | 96-363-03 |
| CEF | 500351 |
Engine & Model Compatibility
Supplier-listed applications are grouped below by horsepower and model year. The supplier record does not specify individual model codes, serial-number ranges or a single engine stroke configuration. Verify all of these details against the engine identification plate and the original impeller before installation.
| Brand | Model Information | Rated HP | Stroke | Supplier-Listed Years | Reference Numbers |
|---|---|---|---|---|---|
| Evinrude / Johnson | Individual model codes not specified | 10 HP | Verify engine specification | 1949–1957 | 375638 / 0775518 |
| Evinrude / Johnson | Individual model codes not specified | 15 HP | Verify engine specification | 1953–1965 | 375638 / 0775518 |
| Evinrude / Johnson | Individual model codes not specified | 18 HP | Verify engine specification | 1953–1965 | 375638 / 0775518 |
| Evinrude / Johnson | Individual model codes not specified | 20 HP | Verify engine specification | 1966–1973 | 375638 / 0775518 |
| Evinrude / Johnson | Individual model codes not specified | 25 HP | Verify engine specification | 1969–1978 | 375638 / 0775518 |
Technical Specs
- Product Type
- Water pump impeller
- Application
- Selected Evinrude and Johnson outboard water-pump systems
- Horsepower Range
- 10 HP, 15 HP, 18 HP, 20 HP and 25 HP applications as listed by the supplier
- Supplier-Listed Model Years
- 1949–1978, depending on horsepower
- Installation
- Replacement component installed in the water-pump housing
- Package Type
- Single impeller; not a complete water-pump kit
- Stroke
- Not specified in the supplier fitment record; verify before ordering
- Manufacturer Warranty
- Not specified in the supplier record
What’s in the Box
- 1 × Water pump impeller
The key, water-pump housing, wear plate, gaskets, seals and fasteners are not listed as included. Reuse serviceable components or obtain replacement parts separately as required by the engine service procedure.
Installation Notes
- Disconnect the spark plug wires and follow the engine manufacturer’s safety procedure before servicing the outboard.
- Remove the lower unit according to the service manual for your exact engine model and serial range.
- Remove the water-pump housing and inspect the housing, wear plate, keyway and related seals for wear or damage.
- Remove the old impeller and clean the mating surfaces. Do not discard a reusable key unless it is damaged or the service manual requires replacement.
- Install the replacement impeller in the correct orientation for the engine. The impeller key is not listed as included with this single-component product.
- Reinstall the water-pump housing and any serviceable or separately purchased gaskets and seals using the engine manufacturer’s torque specifications.
- Reinstall the lower unit, align the driveshaft and shift-shaft components, and tighten all fasteners according to the service manual.
- Test the engine in an appropriate water source and confirm normal cooling-water flow before returning it to service.
Troubleshooting & FAQ
How can I confirm this impeller fits my exact engine?
Match the engine brand, horsepower, model year and serial-number range to the service manual or parts diagram. Also compare the original impeller’s outside diameter, inside diameter, height, blade configuration and keyway. The supplier record does not provide individual model codes or serial ranges, so do not rely on horsepower alone.
Does this product include the impeller key?
No key is listed as included. This listing is for one replacement impeller. Inspect the existing key and replace it separately if it is worn, damaged or missing.
What are the signs of a failing water-pump impeller?
Common symptoms include weak or absent cooling-water flow, overheating, an overheating alarm or steam near the exhaust. Stop the engine promptly if cooling performance is abnormal and inspect the water-pump system.
How often should a water-pump impeller be replaced?
Inspect the impeller during the maintenance interval specified for your engine. Replacement timing depends on operating hours, storage conditions and exposure to sand, silt or salt water. Replace it sooner if the blades are cracked, permanently bent, brittle or damaged.
Is this an OEM part?
This is an aftermarket replacement impeller. The OEM and aftermarket numbers shown above are supplier-listed reference numbers for identification and cross-reference purposes.
What should I do if the application is uncertain?
Do not install the part until the engine model, year, serial range and original impeller specifications have been confirmed. A qualified marine technician can verify the application when the engine identification or existing part is unclear.
Safety & Important Info
- Confirm the complete engine model, year, serial range and impeller dimensions before ordering.
- Do not operate an outboard with weak or absent cooling-water flow.
- Use the manufacturer’s service manual for removal, installation and torque specifications.
- This product is a single aftermarket impeller, not a complete water-pump rebuild kit.
- Professional installation is recommended when the lower unit or water-pump assembly is unfamiliar.
About Sea Sierra
- Marine Replacement Parts — We provide replacement components for common marine maintenance and repair applications.
- Application-Focused Listings — Product references and fitment information are provided to help identify the correct replacement part.
- Installation Responsibility — Always verify the exact engine application and follow the manufacturer’s service procedures before installation.
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