Water Pump Impeller Kit – Fits Yamaha 6/8 HP Outboards (Replaces 6N0-W0078-A0-00, 6G1-W0078-A1-00)

Water Pump Impeller Kit – Fits Yamaha 6/8 HP Outboards (Replaces 6N0-W0078-A0-00, 6G1-W0078-A1-00)

This water pump impeller service kit provides a complete solution for maintaining the cooling system on select Yamaha 2-Stroke outboards. It is designed for Yamaha 6 HP (1988–2000) and 8 HP (1984 and newer) engines, including the 6C, 6D, 6J, 8C, 8J, and 8N series models.

This kit is a direct replacement for Yamaha part numbers 6N0-W0078-A0-00, 6G1-W0078-A1-00, 6G1-W0078-00-00, and 6G1-W0078-01-00.

• Complete Service Kit: Includes all necessary gaskets, plates, and a neoprene impeller for a full water pump rebuild.
• Installation Location: Service is performed on the lower unit of the outboard.

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.

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.

Yamaha Models

Mercury/Mariner Models

Technical Specifications

Package Contents

• 1 x Water Pump Gasket (6G1-44315-A0-00)
• 1 x Cartridge Insert (6G1-44322-00-00)
• 1 x Cartridge Outer Plate (6G1-44323-00-00)
• 1 x Water Seal Damper 2 (647-44366-00-00)
• 1 x Impeller (6G1-44352-00-00)
• 2 x Plates (6G1-44328-00-00)
• 4 x Bolts (97080-06045-00)

Installation Guide

1. Disconnect the negative battery cable and ensure the outboard is shifted into the neutral position.
2. Carefully unbolt and remove the lower unit assembly from the outboard's leg. Place it on a stable workbench.
3. Locate the water pump housing on the lower unit and remove the bolts securing it. Lift the housing off the driveshaft.
4. Remove the old impeller, gaskets, wear plate, and any other components included in your new kit.
5. Thoroughly clean the interior surfaces of the pump housing and the base plate, removing any old gasket material or debris.
6. Install the new cartridge insert and water pump gasket onto the lower unit.
7. Slide the new impeller onto the driveshaft. Turn the driveshaft clockwise while pushing down to seat the impeller blades correctly.
8. Install the new cartridge outer plate and water seal damper.
9. Reinstall the water pump housing and tighten the bolts to the manufacturer's specified torque.
10. Reattach the lower unit to the outboard, ensuring the driveshaft and shift shaft are properly aligned.
11. Once fully assembled, start the engine in a test tank or with a water flusher to verify correct pump operation and check for leaks.

Troubleshooting & FAQ

How do I confirm this kit fits my Yamaha engine?
First, check the "Compatible Engine Models" table on this page. This kit is specifically for Yamaha 6 HP (1988–2000) and 8 HP (1984 and newer) 2-stroke models. It also fits related series like the 6C, 6D, 8C, and 8J. Cross-referencing your engine's model and year is the best way to ensure a match.

What are the signs that my water pump impeller needs to be replaced?
The most common signs of a failing impeller are a weak or non-existent water stream from the "tell-tale" cooling outlet, an audible engine overheating alarm, or a consistently high temperature reading on your gauge.

How often should I replace the water pump impeller?
As a key part of preventative maintenance, it is highly recommended to inspect your impeller annually. We suggest replacing it every 100-200 hours of operation or every other year, whichever comes first—sooner if you frequently run your boat in saltwater, silt, or sand.

Is the impeller in this kit made of the same material as the OEM part?
This kit includes a high-quality neoprene rubber impeller, a material chosen for its durability and reliable performance in marine environments. It is designed to meet or exceed original equipment manufacturer (OEM) specifications.

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.