Water Pump Impeller – Fits Johnson/Evinrude 9.5/10 HP (Replaces 377178, 775519)
Water Pump Impeller – Fits Johnson/Evinrude 9.5/10 HP (Replaces 377178, 775519) 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 Johnson/Evinrude 9.5/10 HP (Replaces 377...
Product Details
This high-quality Water Pump Impeller – Fits Johnson/Evinrude 9.5/10 HP (Replaces 377178, 775519) is engineered for Johnson/Evinrude 9.5 HP (1964–1973) and 10 HP (1958–1963) 2-Stroke outboard engines, ensuring your cooling system functions correctly. It is built to meet or exceed original equipment specifications for reliable performance.
This component is a direct replacement for multiple OEM and aftermarket part numbers, including Johnson/Evinrude 377178, 775519, 777833, Sierra 18-3003, and others, offering a precise fit and restoring cooling efficiency.
- Engineered for direct OEM replacement installation.
- Features a durable 6-blade design made from neoprene rubber.
- Designed to restore cooling system performance and prevent overheating.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 377178 / 0377178 / 775519 / 0775519 / 777833 |
| Sierra | 18-3003 |
| GLM | 89670 |
| Mallory Marine | 9-45218 / 9-45218-10 |
| SEI Marine | 96-361-03BE |
| CEF | 500349 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | Multiple | 9.5 HP | 2-Stroke | 1964–1973 | 377178 | |
| Johnson/Evinrude | Multiple | 10 HP | 2-Stroke | 1958–1963 | 377178 | |
| Johnson/Evinrude | MQ, MQL | 9.5-10 HP | 2-Stroke | Various | 377178 | |
| Johnson/Evinrude | 9R, 9RL | 9.5-10 HP | 2-Stroke | Various | 377178 |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct OEM replacement
- Number of Blades
- 6
- Material
- Neoprene rubber
- Overall Diameter
- 69.6 mm (2.74 inch)
- Height
- 12.8 mm (0.5 inch)
- Shaft Diameter
- 14.1 mm (0.555 inch)
- Weight
- 38g (1.34 oz)
What’s in the Box
- 1 x Water Pump Impeller (Replaces 377178/775519)
Installation Notes
- Disconnect the battery and spark plug wires for safety.
- Place a drain pan under the lower unit and remove the gearcase oil drain screw to empty the lubricant.
- Unbolt and carefully lower the gearcase (lower unit) from the outboard midsection.
- Remove the screws securing the water pump housing cover.
- Slide the old impeller off the driveshaft, noting the orientation of the blades. Clean any debris from the housing.
- Lightly grease the new impeller with marine grease and slide it onto the driveshaft, turning the shaft in its normal rotational direction to bend the blades correctly.
- Reassemble the pump housing, reinstall the lower unit with a new gasket, and refill the gearcase oil.
Troubleshooting & FAQ
How do I know if this impeller fits my specific model?
This impeller is designed for Johnson/Evinrude 9.5 HP (1964–1973) and 10 HP (1958–1963) models. Always cross-reference the part numbers in our Part Number Matrix with your service manual or original part to guarantee a match.
What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent water stream from the tell-tale port, engine overheating alarms, and reduced engine performance. Visible signs on the old impeller include cracked, brittle, or worn blades.
How often should this impeller be replaced?
As a general maintenance guideline, we recommend inspecting the impeller annually and replacing it every 1-2 years or every 100-200 hours of use, depending on operating conditions (especially in saltwater or sandy/silty water).
Is this impeller more durable than the original OEM part?
This aftermarket impeller is manufactured with high-quality neoprene rubber to meet or exceed OEM specifications for durability and performance. It is designed to offer comparable service life under normal operating conditions.
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.
Payment & Security
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