Water Pump Impeller – Fits Johnson/Evinrude 4-8 HP (Replaces 389576, 433914, 436137, 777822)
Water Pump Impeller – Fits Johnson/Evinrude 4-8 HP (Replaces 389576, 433914, 436137, 777822) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
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 4-8 HP (Replaces 389576...
Product Details
This replacement Water Pump Impeller – Fits Johnson/Evinrude 4-8 HP Outboards (Replaces 389576, 433914, 436137, 777822) is designed for a precise fit on Johnson/Evinrude 4-8 HP 2-Stroke engines (1980–1997) and 5-6 HP 4-Stroke engines (1998 and up). It restores cooling system performance, protecting your engine from overheating.
This component provides a direct interchange for OEM parts 389576, 433914, 436137, 777822, and 778225, as well as aftermarket parts from Sierra (18-3091), Mallory (9-45214), GLM Marine (89500), and CEF (500354/500358).
- Engineered as a direct replacement for a straightforward installation (professional install recommended).
- Constructed from durable neoprene rubber with a brass center hub for longevity in marine environments.
- This complete kit includes the impeller, impeller key, and gasket seal for a comprehensive service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 389576 |
| Johnson/Evinrude | 433914 |
| Johnson/Evinrude | 436137 |
| Johnson/Evinrude | 777822 |
| Johnson/Evinrude | 778225 |
| Sierra | 18-3091 |
| Mallory | 9-45214 |
| GLM Marine | 89500 |
| CEF | 500354 |
| CEF | 500358 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Johnson/Evinrude Engines: Please verify your specific model and year. While this part fits a wide range, consulting manufacturer documentation for edge cases is recommended.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Johnson/Evinrude | Outboard | 4 | 2-Stroke | 1986–1992 | 389576/433914 |
| Johnson/Evinrude | Outboard | 4 Deluxe | 2-Stroke | 1980–1997 | 389576/433914 |
| Johnson/Evinrude | Outboard | 4.5 | 2-Stroke | 1980–1997 | 389576/433914 |
| Johnson/Evinrude | Outboard | 5 | 2-Stroke | 1980–2001 | 389576/433914 |
| Johnson/Evinrude | Outboard | 5 | 4-Stroke | 1998 and up | 389576/433914 |
| Johnson/Evinrude | Outboard | 6 | 2-Stroke | 1984–2005 | 389576/433914 |
| Johnson/Evinrude | Outboard | 6 | 4-Stroke | 1998 and up | 389576/433914 |
| Johnson/Evinrude | Outboard | 8 | 2-Stroke | 1986–1997 | 389576/433914 |
| Johnson/Evinrude | Outboard | 8 | 4-Stroke | 1980–2005 | 389576/433914 |
Technical Specs
- Product Type
- Water Pump Impeller
- Housing Material
- Neoprene rubber with brass hub
- Number of Blades
- 6
- Overall Diameter
- 38.4 mm (1.51 in)
- Height
- 17.9 mm (0.70 in)
- Shaft Size
- 11.2 mm (0.44 in)
- Weight
- 34 g (1.05 oz)
- Other Technical Attributes
- Brass center hub for durability
What’s in the Box
- 1 x Water Pump Impeller (436137/389576)
- 1 x Impeller Key (0331130/300611)
- 1 x Gasket/Seal (0325040)
Installation Notes
- Disconnect the battery and ensure the engine is off and cool.
- Remove the lower unit (gearcase) from the outboard motor.
- Unscrew and remove the water pump housing cover to access the impeller.
- Carefully note the blade orientation before removing the old impeller. Slide it off the driveshaft.
- Remove the old impeller key and gasket. Thoroughly clean the housing interior, removing any debris or corrosion.
- Lightly lubricate the new gasket and housing interior with a marine-safe lubricant.
- Insert the new impeller key into the driveshaft slot.
- Slide the new impeller onto the shaft, rotating it in the direction of engine operation to correctly orient the blades.
- Reinstall the water pump housing and torque its bolts to the manufacturer's specifications.
- Reattach the lower unit, ensuring all connections are secure. Once reassembled, test the engine with a water supply to verify proper cooling system operation.
Troubleshooting & FAQ
How do I confirm this impeller fits my exact engine model?
The best way is to match your engine's original part number to one of the cross-reference numbers listed in our Part Number Matrix. Additionally, check your model and year against the Engine & Model Compatibility table. If you are unsure, consult your engine's service manual or contact us with your engine's serial number.
What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, and reduced engine performance. Visually, a worn impeller may have cracked, brittle, or missing blades.
How often should I replace my impeller?
As a general maintenance guideline, impellers should be inspected annually and replaced every 1-2 years, regardless of visual condition. Replacement frequency depends on usage hours and operating conditions (e.g., saltwater vs. freshwater).
Is the key and gasket included with this impeller?
Yes. This kit includes the impeller, impeller key, and the necessary gasket/seal for a complete installation, as detailed in the "What's in the Box" section.
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
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
