Water Pump Impeller – Fits Johnson/Evinrude 4-8 HP Outboards (Replaces 389576, 433914, 436137, 777822)

Water Pump Impeller – Fits Johnson/Evinrude 4-8 HP Outboards (Replaces 389576, 433914, 436137, 777822)

This water pump impeller is designed for a precise fit on a range of Johnson/Evinrude outboard engines, including 4-8 HP 2-Stroke models (1980-1997) and 5-6 HP 4-Stroke models (1998 and up). It ensures reliable engine cooling performance by replacing worn or damaged original components.

This component is a direct replacement for multiple OEM and aftermarket part numbers, including Johnson/Evinrude 389576, 433914, 436137, 777822, and 778225.

• Complete Kit: Includes the impeller, impeller key, and gasket for a comprehensive service.
• Durable Construction: Made from high-quality neoprene rubber with a brass hub for corrosion resistance and longevity.
• Installation Method: Direct replacement. Professional installation is recommended.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

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.

Technical Specifications

Package Contents

• 1 x Water Pump Impeller (436137/389576)
• 1 x Impeller Key (0331130/300611)
• 1 x Gasket/Seal (0325040)

Installation Guide

1. Disconnect the negative battery cable.
2. Remove the lower unit (gearcase) from the outboard motor.
3. Unscrew the bolts securing the water pump housing and remove the housing.
4. Take note of the old impeller's blade direction, then remove the old impeller, gasket, and impeller key.
5. Thoroughly clean the inside of the water pump housing and the wear plate.
6. Install the new gasket and place the new impeller key in its slot on the driveshaft.
7. Slide the new impeller onto the driveshaft. Turn the driveshaft clockwise while pushing down to seat the blades correctly inside the housing cup.
8. Reinstall the water pump housing and tighten the bolts to the manufacturer's specified torque.
9. Reattach the lower unit to the outboard motor.
10. Reconnect the battery cable and test the engine's cooling system using a water supply (flushing muffs).

Troubleshooting & FAQ

First, check the "Compatible Engine Models" table on this page. Compare your engine's brand, model, horsepower, and year against the listed applications. Second, use the "Part Number Cross-Reference" table to see if your existing part number matches any of the listed equivalents. For Johnson/Evinrude owners, our serial number guide can help you verify your model details.

Common signs include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "telltale" outlet, and a dry, cracked, or stiff appearance of the old impeller upon inspection. Failure to replace a worn impeller can lead to severe engine damage.

For preventative maintenance, it is recommended to replace your impeller every 1-2 years or every 100-200 hours of use, whichever comes first. Replacement intervals may vary depending on operating conditions (e.g., frequent use in sandy or saltwater).

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.

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.

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?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.