Water Pump Impeller Repair Kit – Fits Yamaha 6/8 HP 2-Stroke Outboards

Water Pump Impeller Repair Kit – Fits Yamaha 6/8 HP 2-Stroke Outboards

This water pump impeller service kit provides a complete solution for maintaining the cooling system on select Yamaha and Mariner 2-stroke outboard engines. It is designed to restore cooling performance and prevent engine overheating, ensuring reliability on the water.

This kit is compatible with Yamaha 6 HP and 8 HP models (1984–2009) and Mariner 6 HP and 8 HP models (1984–1986), including 6C, 6D, 8C, 8J, and 8N series engines. It is a direct replacement for OEM part numbers 6N0-W0078-A0-00 and 6G1-W0078-A1-00.

• Installation Method: Installs in the lower unit as part of routine cooling system service.
• Core Component: Includes a durable neoprene impeller designed for efficient water circulation.
• Complete Kit: Contains all necessary gaskets, plates, seals, and bolts for a full replacement.

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

Yamaha Outboards

Mariner Outboards

Technical Specifications

Package Contents

• 1 x Water Pump Gasket (6G1-44315-A0-00)
• 1 x Cartridge Insert (6G1-44322-00-00/6G1-44322-02-00)
• 1 x Cartridge Outer Plate (6G1-44323-00-00)
• 1 x Water Seal Damper (647-44366-00-00)
• 1 x Impeller (6G1-44352-00-00)
• 1 x Plate Kit (6G1-44328-00-00)
• 4 x Bolts (97080-06405-00)

Installation Guide

1. Shift the outboard into neutral and disconnect the battery.
2. Unbolt and carefully lower the gearcase (lower unit) from the engine's upper casing.
3. Locate and unbolt the water pump housing cover, which sits on top of the lower unit.
4. Note the rotational direction of the old impeller's vanes before removing it.
5. Remove the old impeller, gaskets, wear plate, and seals from the assembly.
6. Thoroughly clean all mating surfaces to remove any old gasket material or debris.
7. Install the new water seal damper, gaskets, and plates provided in the kit.
8. Slide the new impeller onto the driveshaft, turning it in the correct direction (noted in step 4) to seat the vanes properly inside the housing.
9. Reinstall the water pump housing and tighten its bolts to the manufacturer's specified torque.
10. Carefully raise and reattach the lower unit to the outboard engine, ensuring all connections are secure.
11. Reconnect the battery.
12. Before regular operation, test the engine with a reliable water supply (flusher or in water) to confirm strong water flow from the tell-tale port.

Troubleshooting & FAQ

How do I confirm this kit fits my specific engine model?
This kit is designed for Yamaha 6/8 HP (1984–2009) and Mariner 6/8 HP (1984–1986) 2-stroke outboards. Please review the "Compatible Engine Models" table and cross-reference your engine's model and year. Verifying the OEM part number (e.g., 6N0-W0078-A0-00) against your service manual is the best way to ensure an exact match.

What are the signs that my water pump impeller needs to be replaced?
Common signs of a failing impeller include a weak or intermittent water stream from the "tell-tale" port, engine overheating alarms, or a noticeable drop in cooling performance. Visual inspection may reveal cracked, brittle, or worn-down impeller vanes.

How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to inspect and/or replace the water pump impeller every 1-2 years or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).

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.