Water Pump Impeller Repair Kit - Fits Mercury/Tohatsu/Nissan 4-6HP Outboards

Water Pump Impeller Repair Kit – Fits Mercury/Tohatsu/Nissan 4-6HP Outboards (Replaces 369-87322-1)

This water pump impeller repair kit is designed for Mercury, Tohatsu, and Nissan 4HP, 5HP, and 6HP 4-stroke outboard motors. It serves as a direct replacement part, ensuring proper fit and function for routine maintenance or repairs of your engine's cooling system.

This kit provides a reliable aftermarket solution, replacing several OEM and aftermarket part numbers to cover a wide range of compatible models.

• Installation: Direct replacement for a straightforward installation.
• Components: Includes the impeller and necessary components for a complete water pump service.

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 Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

For Tohatsu and Nissan owners, confirm your engine model/year in the table below.

Technical Specifications

Installation Guide

1. Ensure the engine is off and disconnect the battery. Shift the outboard into the neutral position.
2. Carefully remove the bolts securing the lower unit (gearcase) to the upper leg of the outboard.
3. Gently lower the gearcase to separate it from the driveshaft housing, exposing the water pump assembly.
4. Remove the bolts on the water pump housing cover to access the impeller.
5. Take note of the old impeller's orientation, then remove it, along with the drive key, gaskets, and wear plates.
6. Thoroughly clean the inside of the housing and all mating surfaces to remove any old gasket material or debris.
7. Install the new gaskets and insert the new impeller drive key into the driveshaft.
8. Lubricate the new impeller and housing. Slide the new impeller onto the driveshaft while turning it clockwise to bed the vanes correctly.
9. Reinstall the water pump housing and tighten the bolts to the manufacturer's specified torque.
10. Carefully guide the driveshaft back into the engine as you raise the lower unit, ensuring the water tube aligns correctly. Reinstall and tighten the gearcase bolts.
11. Reconnect the battery. Before starting the engine, supply water to the lower unit and check for a strong stream from the tell-tale outlet.

Troubleshooting & FAQ

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

A: The best way to ensure compatibility is to verify your part number. Check the "Part Number Cross-Reference" table to see if your outboard's original part number is listed. Also, review the "Compatible Engine Models" table to confirm your engine's model and horsepower are included.

Q: What are the symptoms of a bad or failing water pump impeller?

A: The most common signs are an overheating engine alarm or a noticeably weak or non-existent stream of water from the "tell-tale" outlet on the side of your motor. This indicates insufficient water circulation, which requires immediate attention.

Q: How often should the water pump impeller be replaced?

A: As a general rule, it is recommended to inspect and/or replace the impeller every one to two years, or every 100-200 hours of use. However, usage in saltwater or sandy/murky water may require more frequent changes.

Q: OEM vs. Aftermarket?

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 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.