Water Pump Impeller – Fits Johnson Evinrude OMC BRP 9.5HP 10HP Outboard Motors
This premium aftermarket water pump impeller is designed to fit Johnson Evinrude OMC BRP 9.5HP and 10HP outboard motors. Engineered to meet OEM specifications, this impeller ensures reliable cooling performance and long service life for your engine.
Direct replacement for OEM part numbers 377178 and 775519, as well as Sierra 18-3003. Compatible with engines manufactured between 1958 and 1973.
- Complete impeller kit with key/pin included
- Brass hub design for enhanced durability
- High-quality neoprene rubber construction for superior heat and water resistance
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Johnson Evinrude OMC |
377178 |
| Johnson Evinrude OMC |
775519 |
| Sierra |
18-3003 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here's a guide to help you identify your engine's serial/model: Johnson/Evinrude Serial Number Guide.
| Brand |
Rated HP |
Years |
OEM Part No. |
| Johnson Evinrude OMC BRP |
9.5 HP |
1964-1973 |
377178, 775519 |
| Johnson Evinrude OMC BRP |
10 HP |
1958-1963 |
377178, 775519 |
Technical Specifications
| Specification |
Value |
| Material |
High-Quality Metal Alloy (Brass Hub) and Neoprene Rubber |
| External Impeller Overall Diameter |
69.00 mm / 2.72 inch |
| Internal Shaft Insert Diameter |
14.10 mm / 0.56 inch |
| Hub Type |
Brass |
Package Contents
- 1 × Outboard Rubber Impeller with Key/Pin
Installation Guide
- Disconnect the fuel line and remove the spark plug wire to prevent accidental engine start.
- Remove the lower unit from the outboard motor following your engine's service manual.
- Disassemble the water pump housing and remove the old impeller carefully.
- Clean the impeller housing thoroughly, removing any debris or old gasket material.
- Lubricate the new impeller with waterproof grease or soapy water for easier installation.
- Insert the key/pin into the driveshaft slot, ensuring it is properly seated.
- Carefully slide the new impeller onto the driveshaft, rotating the blades in the correct direction as needed.
- Install the impeller plate and ensure all components are properly aligned.
- Replace the water pump housing gaskets with new ones to prevent leaks.
- Reassemble the water pump housing and secure all bolts to the manufacturer's torque specifications.
- Reattach the lower unit to the outboard motor and reconnect all hoses and fittings.
- Test the water pump by running the engine with the cooling system engaged; verify proper water flow.
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my Johnson or Evinrude outboard?
A: Check the compatible engine models table above to verify your HP rating and year range. You can also cross-reference OEM part numbers 377178 or 775519 with your engine's service manual or parts diagram.
Q: How often should I replace my water pump impeller?
A: Most manufacturers recommend replacing the impeller every 2-3 years or every 200-300 hours of operation, whichever comes first. If you notice overheating, reduced water flow, or visible cracks/wear on the impeller blades, replace it immediately.
Q: What are the signs that my impeller is failing?
A: Common symptoms include engine overheating, weak or no water discharge from the cooling outlet, steam from the engine, and reduced performance. Inspect the impeller annually even if no symptoms are present.
Q: Does this impeller come with the installation key/pin?
A: Yes, this kit includes the impeller with the key/pin required for installation on your Johnson Evinrude outboard motor.
Q: What is the difference between this aftermarket impeller and the OEM version?
A: This aftermarket impeller is manufactured to OEM specifications using comparable high-quality neoprene rubber and a brass hub. It offers the same fit and performance as the original part at a more competitive price point.
Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.