Water Pump Impeller Service Kit – Fits Johnson Evinrude 40-75 HP Outboard Motors (Replaces 396725, Sierra 18-3053)

Water Pump Impeller Service Kit – Fits Johnson Evinrude 40-75 HP Outboard Motors (Replaces 396725, Sierra 18-3053)

This water pump impeller service kit is designed for Johnson/Evinrude 40-75 HP, 2-Stroke outboard motors (1979-2012). It specifically fits applications with a large gearcase and a six-vane impeller design, including many loopcharged models.

This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Johnson/Evinrude 396725/0396725, 437080/0437080, 777820/0777820, 389557/0389557, 432954/0432954; Sierra 18-3053; GLM 89710; Mallory 9-45207; SEI 96-366-03BE; and Red Rhino JE-214.

• Engineered with a durable marine-grade CR Neoprene rubber impeller for reliable performance.
• Includes a new impeller, drive shaft key, seal O-rings, and gaskets for a complete service.
• Designed for models using a plastic wedge drive key.

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 Rubber Impeller (Replaces 396725)
• 1 x Drive Shaft Key (Replaces 0331901)
• This kit also includes the necessary gaskets and seal O-rings for a complete installation.

Installation Guide

1. Disconnect the spark plug wires and the battery to prevent accidental starting.
2. Drain the gearcase oil into a suitable container by removing the drain and vent plugs.
3. Remove the bolts securing the lower unit (gearcase) to the engine's midsection.
4. Carefully lower and separate the gearcase from the driveshaft housing. Note the position of the shift rod.
5. Unscrew the bolts on the water pump housing and remove the housing assembly.
6. Slide the old impeller off the driveshaft, and remove the impeller key, gaskets, and wear plate.
7. Clean all mating surfaces thoroughly, removing any old gasket material or sealant.
8. Install the new gasket, wear plate, and drive key. Slide the new impeller onto the driveshaft, turning it clockwise to seat the vanes.
9. Apply a light coat of marine grease or soap to the inside of the pump housing and reinstall it over the impeller.
10. Torque the housing bolts to the manufacturer's specifications.
11. Reattach the lower unit, ensuring the driveshaft, water tube, and shift rod align correctly.
12. Refill the gearcase with fresh oil, reinstall the plugs, and test the engine in the water, confirming a steady stream from the tell-tale.

Troubleshooting & FAQ

Q: How do I confirm this impeller kit fits my specific engine model?

A: First, check your engine's horsepower, year, and cylinder count against our "Compatible Engine Models" table. This kit is specifically for 40-75 HP Johnson/Evinrude models with a large gearcase and a six-vane, plastic wedge key impeller. Visually comparing your old impeller and key to our product photos is the best way to ensure a match.

Q: What are the common signs that my water pump impeller is failing?

A: The most common indicators of a worn or damaged impeller are an overheating engine at idle or low speeds, or a weak, intermittent, or non-existent water stream from the "tell-tale" outlet port. Reduced engine performance can also be a symptom.

Q: How often should I replace my outboard's water pump impeller?

A: As a critical preventative maintenance item, we recommend replacing your impeller every 1-2 years or every 100-200 operating hours, whichever comes first. Usage in saltwater or sandy/silty conditions may require more frequent inspections and replacements.

Q: Is this an OEM part?

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, especially the six-vane design and plastic wedge key, 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.