6H3-W0078-A0 Water Pump Impeller Kit for Yamaha 60F 70B FT50B FT50C FT50G FT50J FT60B FT60D FT60G | JLM Marine

Water Pump Impeller Kit – Fits Yamaha 2-Stroke 60-70 HP & 4-Stroke 50-60 HP High Thrust Outboards

This water pump impeller service kit is designed for Yamaha 2-stroke 60 HP and 70 HP outboards, as well as 4-stroke 50 HP and 60 HP high thrust models. It ensures reliable cooling system performance by delivering a complete set of components needed for routine water pump maintenance.

This kit directly replaces Yamaha OEM part numbers 6H3-W0078-00-00, 6H3-W0078-01-00, 6H3-W0078-02-00, and 6H3-W0078-A0-00, as well as Sierra Marine part numbers 18-3466, 18-3428, and 18-3461.

• Includes all essential gaskets, o-ring, impeller, and key for complete service
• Compatible with both 2-stroke and 4-stroke Yamaha outboards
• Designed for high thrust 4-stroke models FT50 and FT60 series

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.

Technical Specifications

Package Contents

This complete water pump impeller service kit includes the following components:

• 1 × Water Pump Impeller (6H3-44352-01 / 697-44352-00)
• 1 × Key, Woodruff (90280-03M03-00)
• 1 × Gasket, Water Pump (688-44316-A0-00)
• 1 × Gasket, Water Pump (6H3-44315-A0-00)
• 1 × Gasket, Outer Plate (6H3-44324-A0-00)
• 1 × O-Ring (93210-46044-00)

Installation Guide

1. Disconnect the fuel line and battery to ensure safe working conditions. Remove the lower unit from the outboard motor according to your engine's service manual.
2. Access the water pump housing by removing the retaining bolts. Carefully separate the housing to expose the old impeller and gaskets.
3. Remove the old impeller by gently pulling it off the driveshaft. If it's stuck, use a suitable puller tool to avoid damaging the shaft.
4. Clean all mating surfaces thoroughly, removing any old gasket material, debris, or corrosion. Ensure surfaces are smooth and dry before reassembly.
5. Install the Woodruff key into the driveshaft keyway. Make sure it seats fully and securely.
6. Lubricate the new impeller with a water-resistant marine grease or glycerin. This helps the impeller slide on and protects it during initial startup.
7. Install the new impeller onto the driveshaft with the vanes oriented in the correct rotation direction (typically counterclockwise when viewed from above). Rotate it gently to ensure proper seating.
8. Position the new gaskets and O-ring in their respective locations on the pump housing and outer plate. Do not reuse old gaskets.
9. Reassemble the water pump housing, aligning all bolt holes carefully. Tighten bolts evenly in a criss-cross pattern to the torque specification in your service manual.
10. Reinstall the lower unit onto the outboard, ensuring the driveshaft engages properly. Reconnect all fasteners and torque to specification.
11. Reconnect the fuel line and battery, then perform a water test. Check for proper water flow from the tell-tale (indicator stream) within the first 15 seconds of operation.
12. Inspect for leaks around the pump housing and lower unit seals during and after the test run. Address any issues immediately before regular use.

Troubleshooting & FAQ

Q: How do I confirm this water pump kit fits my specific Yamaha outboard?
A: Check the compatible engine models table above to verify your model and year range. You can also cross-reference the OEM part number (6H3-W0078-A0) with your engine's parts diagram using the Yamaha parts catalog link provided.

Q: How often should I replace the water pump impeller?
A: Yamaha recommends replacing the impeller every 2-3 years or every 200-300 hours of operation, whichever comes first. If you notice overheating, reduced water flow from the tell-tale, or the engine has been run dry, replace the impeller immediately.

Q: What are the signs that my water pump impeller is failing?
A: Common symptoms include weak or no water flow from the tell-tale indicator, engine overheating, steam from the engine, loss of power, or an audible alarm. Inspect and replace the impeller promptly if you notice any of these issues.

Q: Can I use this kit on standard (non-high thrust) 50 HP or 60 HP Yamaha 4-stroke engines?
A: This kit is specifically designed for high thrust models (FT50 and FT60 series). Standard F50 and F60 models may require different part numbers, so verify your exact engine model and consult the parts diagram before ordering.

Q: Do I need any special tools to install this water pump kit?
A: Basic hand tools (sockets, wrenches, screwdrivers) are typically sufficient. A torque wrench is recommended for proper bolt tightening, and an impeller puller may be helpful if the old impeller is difficult to remove.

Q: Is this an OEM part or an aftermarket replacement?
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.