Water Pump Impeller Kit – Fits Johnson/Evinrude 40-70 HP (Replaces 5000308, 438593, 437772)

Water Pump Impeller Kit – Fits Johnson/Evinrude 40-70 HP (Replaces 5000308, 438593, 437772)

This water pump impeller repair kit is designed for Johnson and Evinrude 40-70 HP, 2-Stroke outboards from 1998–2005. It provides a reliable solution for maintaining your engine’s cooling system for optimal performance and longevity.

This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Johnson/Evinrude 5000308, 438593, 437772, 437771, 769459; Sierra 18-2810; GLM 12235; Mercury Mariner 27-43777-2/27-437772; and OMC/Johnson/Evinrude 0508662.

• Complete Rebuild Kit: Includes all necessary components for a full water pump service: impeller, housing, wear plate, gaskets, seals, and hardware.
• Direct Replacement Fit: Engineered to meet or exceed OEM specifications for a direct, hassle-free installation.
• Quality Manufacturing: Produced in an ISO9002 certified facility to ensure consistent quality and durability.

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 O-Ring (335132)
• 1 x Grommet (315748)
• 1 x Impeller (396725)
• 1 x Wear Plate (341038)
• 1 x Gasket (336530)
• 1 x Gasket (339830)
• 1 x Seal (324981)
• 1 x Flywheel Key (331901)
• 1 x Impeller Key (334897)
• 1 x Housing (438545)
• 1 x Insert Cartridge (340619)
• 2 x Bolt (337574)
• 2 x Bolt (10-28667)

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is secure before beginning work.
2. Access the Pump: Remove the lower unit (gearcase) from the outboard motor to access the water pump assembly.
3. Disassemble: Carefully unbolt and remove the existing water pump housing, taking note of the order of the components.
4. Inspect & Remove Old Parts: Remove the old impeller, wear plate, gaskets, and seals. Check the driveshaft and housing for scoring or damage.
5. Clean Surfaces: Thoroughly clean all mounting surfaces to ensure a proper seal with the new gaskets.
6. Install New Components: Place the new gasket and wear plate onto the lower unit. Install the new impeller key on the driveshaft.
7. Install Impeller: Slide the new impeller onto the driveshaft. Turn the shaft clockwise while pushing down on the housing to correctly orient the impeller vanes.
8. Reassemble: Install the new seals and gaskets on the housing. Secure the housing with the provided bolts, tightening them to the manufacturer's recommended torque specifications.
9. Reinstall Lower Unit: Reattach the lower unit to the outboard motor.
10. Test Operation: Once reassembled, start the engine in water and verify a strong, steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

How can I confirm this kit fits my specific engine model?

Please check the 'Compatible Engine Models' table on this page, which lists all compatible models, years, and HP ratings. For Johnson/Evinrude engines, you can use our serial number guide to verify your model details and ensure an exact match.

What are common signs that my water pump impeller needs replacement?

The most common signs are the engine overheating at idle or low speeds and a weak or nonexistent water stream from the tell-tale outlet. During a visual inspection, a worn impeller may have cracked, brittle, or permanently curved vanes.

Does this kit include everything I need for a full rebuild?

Yes, this is a complete rebuild kit. It contains all the critical components—including the impeller, housing, wear plate, gaskets, o-rings, and bolts—required for a standard water pump service. Please see the 'Package Contents' list for a detailed breakdown.

OEM vs. Aftermarket?

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.

How fast do you ship and how much does it cost?

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.

What is your warranty and return policy?

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.