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) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
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Water Pump Impeller Kit – Fits Yamaha 6/8 HP Outboards (Replaces 6N...
Water Pump Impeller Kit – Fits Yamaha 6/8 HP Outboards (Replaces 6N0-W0078-A0-00, 6G1-W0078-A1-00) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit – Fits Yamaha 6/8 HP Outboards (Replaces 6N0-W0078-A0-00, 6G1-W0078-A1-00) provides a complete solution for servicing the cooling system on select Yamaha 2-Stroke outboards. It is engineered 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 serves as a direct replacement for Yamaha part numbers 6N0-W0078-A0-00, 6G1-W0078-A1-00, 6G1-W0078-00-00, 6G1-W0078-01-00, and Sierra 18-3460.
- Installation involves a standard lower unit service procedure.
- Features a durable neoprene impeller for reliable performance.
- Includes all necessary gaskets, plates, and hardware for a full replacement.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6N0-W0078-A0-00 |
| Yamaha | 6G1-W0078-A1-00 |
| Yamaha | 6G1-W0078-00-00 |
| Yamaha | 6G1-W0078-01-00 |
| Sierra | 18-3460 |
| Mariner | 47-11590M |
| Mariner | 47-11656M |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha owners, this kit fits a wide range of 6 HP and 8 HP 2-stroke models manufactured from 1984 to the late 2000s. Please match your specific model and year code.
For Mariner owners, this kit cross-references to models from the mid-1980s. Verification against your original part number is strongly recommended.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 6MLHV | 6 | 2-Stroke | 1997 | 6N0-W0078-A0-00 | |
| Yamaha | 6MLHW | 6 | 2-Stroke | 1998 | 6N0-W0078-A0-00 | |
| Yamaha | 6MLHX | 6 | 2-Stroke | 1999 | 6N0-W0078-A0-00 | |
| Yamaha | 6MLHY | 6 | 2-Stroke | 2000 | 6N0-W0078-A0-00 | |
| Yamaha | 6MSHV | 6 | 2-Stroke | 1997 | 6N0-W0078-A0-00 | |
| Yamaha | 6MSHW | 6 | 2-Stroke | 1998 | 6N0-W0078-A0-00 | |
| Yamaha | 6MSHX | 6 | 2-Stroke | 1999 | 6N0-W0078-A0-00 | |
| Yamaha | 6MSHY | 6 | 2-Stroke | 2000 | 6N0-W0078-A0-00 | |
| Yamaha | 8MLHV | 8 | 2-Stroke | 1997 | 6N0-W0078-A0-00 | |
| Yamaha | 8MLHW | 8 | 2-Stroke | 1998 | 6N0-W0078-A0-00 | |
| Yamaha | 8MLHX | 8 | 2-Stroke | 1999 | 6N0-W0078-A0-00 | |
| Yamaha | 8MLHY | 8 | 2-Stroke | 2000 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSH | 8 | 2-Stroke | 2004–2009 | 6N0-W0078-A0-00 | Multiple year codes: 0405, 0406, 0407, 0608, 0709 |
| Yamaha | 8MSHA | 8 | 2-Stroke | 2002 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHB | 8 | 2-Stroke | 2003 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHC | 8 | 2-Stroke | 2004 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHD | 8 | 2-Stroke | 2005 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHV | 8 | 2-Stroke | 1997 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHW | 8 | 2-Stroke | 1998 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHX | 8 | 2-Stroke | 1999 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHY | 8 | 2-Stroke | 2000 | 6N0-W0078-A0-00 | |
| Yamaha | 8MSHZ | 8 | 2-Stroke | 2001 | 6N0-W0078-A0-00 | |
| Yamaha | 6C, 6D, 6J | 6 | 2-Stroke | 1996 and newer | 6N0-W0078-A0-00 | |
| Yamaha | 8C, 8J, 8N | 8 | 2-Stroke | 1996 and newer | 6N0-W0078-A0-00 | |
| Mariner | 6C, 6D | 6 | 2-Stroke | 1984–1986 | 47-11590M/11656M | |
| Mariner | 8C | 8 | 2-Stroke | 1984–1986 | 47-11590M/11656M |
Technical Specs
- Product Type
- Water Pump Impeller Service Kit
- Installation
- Lower Unit Service
- Connection
- Direct Fit
- Impeller Material
- Neoprene (some aftermarket variants)
- Warranty
- 1 Year (aftermarket versions)
What’s in the Box
- 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 Notes
- Disconnect the spark plug wires and shift the outboard into the neutral position.
- Place a drain pan under the lower unit and remove the gearcase drain and vent screws.
- Remove the bolts securing the lower unit (gearcase) to the upper leg of the engine.
- Carefully lower the gearcase away from the engine assembly to access the water pump.
- Unbolt and remove the water pump housing to expose the old impeller and wear plate.
- Remove the old impeller, gaskets, plates, and seals. Clean all mating surfaces thoroughly.
- Install the new gasket, wear plate, impeller (with fins pointing in the correct rotational direction), and other components from the kit.
- Reinstall the housing, ensuring a proper seal, and reassemble the lower unit to the engine. Test cooling system operation in water.
Troubleshooting & FAQ
How do I confirm this kit fits my engine?
The surest way is to match your engine's model and year to our compatibility table. Also, compare your existing part numbers to those in our Part Number Matrix. If in doubt, visual comparison with your old parts is recommended.
What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent stream of water from the "telltale" outlet, engine overheating alerts or steam, and a brittle or cracked appearance on the old impeller upon inspection.
How often should I replace my outboard's impeller?
As a general maintenance guideline, inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).
Why does the kit list multiple Yamaha part numbers?
The different numbers (e.g., 6N0-W0078-A0-00, 6G1-W0078-A1-00) represent supersessions and updates over the years. This kit is designed to replace all of them, providing a consolidated solution for a wide range of model years.
Is there a difference in quality between OEM and this aftermarket kit?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and batch-inspected for consistency and reliable performance.
What are your shipping speeds and costs?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free for most orders, with expedited options available at checkout where applicable.
What is the warranty and return policy?
This kit is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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