Water Pump Impeller Service Kit for Yamaha 6/8 HP 2-Stroke Outboards – Replaces 6N0-W0078-A0-00 and 6G1-W0078-A1-00
Water Pump Impeller Service Kit for Yamaha 6/8 HP 2-Stroke Outboards – Replaces 6N0-W0078-A0-00 and 6G1-W0078-A1-00 is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Service Kit for Yamaha 6/8 HP 2-Stroke Outboard...
Water Pump Impeller Service Kit for Yamaha 6/8 HP 2-Stroke Outboards – Replaces 6N0-W0078-A0-00 and 6G1-W0078-A1-00 is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Service Kit for Yamaha 6/8 HP 2-Stroke Outboards is intended for cooling-system service on selected Yamaha and Mariner outboard applications. It is listed for Yamaha 6 HP engines from approximately 1988–2000 and Yamaha 8 HP engines from approximately 1984 onward, including selected 6C, 6D, 6J, 8C, 8J, and 8N series models. Always confirm the exact model, year code, and original part number before ordering.
The kit is listed as a replacement for Yamaha part numbers 6N0-W0078-A0-00, 6G1-W0078-A1-00, 6G1-W0078-00-00, and 6G1-W0078-01-00. It also cross-references to Sierra 18-3460 and selected Mariner references shown below.
- Designed for a standard lower-unit water-pump service procedure.
- Includes a replacement neoprene impeller and related service components.
- Review the complete contents list and compatibility table before installation.
Part Number Matrix
Use these references to compare the replacement kit with the part number removed from your engine.
| 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
Compatibility depends on the complete model designation and year code. The applications below are provided as a reference; match your engine identification and original part number before purchase.
| Brand | Model | Rated HP | Stroke | Years | Reference 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 | Year codes include 0405, 0406, 0407, 0608, and 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 | Confirm the complete model code. |
| Yamaha | 8C, 8J, 8N | 8 | 2-Stroke | 1996 and newer | 6N0-W0078-A0-00 | Confirm the complete model code. |
| Mariner | 6C, 6D | 6 | 2-Stroke | 1984–1986 | 47-11590M / 47-11656M | Verify the original reference. |
| Mariner | 8C | 8 | 2-Stroke | 1984–1986 | 47-11590M / 47-11656M | Verify the original reference. |
Technical Specifications
- Product Type
- Water pump impeller service kit
- Application
- Selected Yamaha and Mariner 6/8 HP 2-stroke outboards
- Installation
- Lower-unit water-pump service
- Fitment
- Reference-based replacement; confirm model, year, and original part number
- Impeller Material
- Neoprene replacement impeller
What's in the Box
- 1 × Water pump gasket — 6G1-44315-A0-00
- 1 × Cartridge insert — 6G1-44322-00-00
- 1 × Cartridge outer plate — 6G1-44323-00-00
- 1 × Water seal damper 2 — 647-44366-00-00
- 1 × Impeller — 6G1-44352-00-00
- 2 × Plates — 6G1-44328-00-00
- 4 × Bolts — 97080-06045-00
Installation Notes
- Disconnect the spark plug wires and place the outboard in neutral.
- Place a drain pan under the lower unit and remove the gearcase drain and vent screws if required by the service procedure.
- Remove the bolts securing the lower unit to the upper leg of the engine.
- Carefully lower the gearcase to access the water pump.
- Remove the water-pump housing to expose the impeller, gaskets, plates, and seals.
- Remove the old components and clean all mating surfaces thoroughly.
- Install the replacement gasket, plates, impeller, and other kit components. Ensure the impeller vanes are oriented correctly for the direction of rotation.
- Reinstall the housing and lower unit, then test cooling-water flow in a suitable water source before normal operation.
Troubleshooting & FAQ
How do I confirm that this kit fits my engine?
Match the complete engine model and year code to the compatibility table, then compare the original part number with the Part Number Matrix. If the model code or removed parts differ, confirm the application before ordering.
What are the signs of a failing water-pump impeller?
Common signs include weak or absent telltale-water flow, overheating warnings, steam, or an impeller that is brittle, cracked, deformed, or missing vanes.
How often should an outboard impeller be replaced?
Inspect the impeller during routine maintenance and replace it when damaged, hardened, cracked, or worn. Replacement intervals depend on operating hours, storage, and water conditions, especially saltwater or sandy environments.
Why are multiple Yamaha part numbers listed?
The listed Yamaha numbers represent related replacement or supersession references used across different applications and model years. Confirm the original number and complete engine model before installation.
Is this an OEM kit?
No. This listing is for an aftermarket replacement service kit. Yamaha, Mariner, and Sierra names and part numbers are used only to identify applications and reference compatibility.
What should I do if the replacement parts do not match my original parts?
Do not force installation or operate the engine. Compare the complete model code and original part number, and contact support for application assistance before modifying or installing the parts.
Safety & Important Information
- Verify the engine model, year code, and original part number before purchase.
- Compare the replacement components with the removed parts before assembly.
- Use the manufacturer's service procedure and appropriate safety equipment.
- Professional installation is recommended if you are not familiar with lower-unit service.
- This is an aftermarket replacement, not an OEM component.
About Sea Sierra
- Marine Replacement Parts — Practical aftermarket components for routine repair and maintenance.
- Application-Focused Listings — Model and part-number references are provided to help with pre-purchase verification.
- Support for Installation Questions — Contact support if your engine identification or original parts do not match the listed application.
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