Water Pump Impeller Kit – Fits Yamaha 15/20HP 4-Stroke (Replaces 6AH-W0078-00)
Water Pump Impeller Kit – Fits Yamaha 15/20HP 4-Stroke (Replaces 6AH-W0078-00) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Water Pump Impeller Kit – Fits Yamaha 15/20HP 4-Stroke (Replaces 6A...
Water Pump Impeller Kit – Fits Yamaha 15/20HP 4-Stroke (Replaces 6AH-W0078-00) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit – Fits Yamaha 15/20HP 4-Stroke (Replaces 6AH-W0078-00) is designed for Yamaha F15C and F20 4-stroke outboard motors manufactured from 2006 to the present. The kit includes all the necessary components to perform a complete service of the water pump and cooling system, ensuring optimal engine performance and longevity.
This kit is a direct replacement for Yamaha OEM part numbers 6AH-W0078-00-00, 6AH-W0078-01-00, and 6AH-W0078-02-00, as well as Sierra Marine part 18-3479.
- Provides a direct OEM-equivalent fit and installation.
- Features a durable neoprene rubber impeller for reliable cooling performance.
- Includes all essential components for a complete water pump rebuild.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Yamaha | 6AH-W0078-00-00 |
| Yamaha | 6AH-W0078-01-00 |
| Yamaha | 6AH-W0078-02-00 |
| Sierra | 18-3479 |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
For Yamaha models, verify your specific model code (e.g., F15CPLH) and production year. Note that compatibility for F9.9 and F13.5 models is based on select aftermarket source data and should be confirmed by matching your existing OEM part number.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F15CPLH | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15CESH | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15CMSH | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15CMLH | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15SEHA | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15LMHA | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15CELH | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15SMHA | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15LPHA | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F15LEHA | 15 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20ELR | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20LPHA | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20LPA | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20PLH | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20SMHA | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20SEA | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20SEHA | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F20PLR | 20 | 4-Stroke | 2006–2023 | 6AH-W0078-00-00 | |
| Yamaha | F9.9 | 9.9 | 4-Stroke | 2009–2016 | 6AH-W0078-00-00 | Per JLM Marine | Yamaha | F13.5 | 13.5 | 4-Stroke | 2007–2009 | 6AH-W0078-00-00 | Per JLM Marine |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Direct OEM replacement
- Housing Material
- Cast Iron
- Weight
- 0.28 kg (0.62 lb)
- Connection
- Driveshaft mount
- Impeller Material
- Neoprene Rubber
- Warranty
- Varies by manufacturer: 30 days (aftermarket) to 1 year
What’s in the Box
- 1 x Water Pump Housing (6AH-44311-00-00)
- 1 x Cartridge Insert (63V-44322-00-00)
- 1 x Water Seal Damper (6L2-44367-00-00/6L2-44367-01-00)
- 1 x Impeller (63V-44352-01-00)
- 1 x Woodruff Key (664-44338-00-00)
- 1 x O-Ring (93210-49046-00)
- 1 x Cartridge Outer Plate (68T-44323-00-00)
- 2 x Dowel Pins (93604-10M03-00/93604-12M07-00)
- 4 x Bolts (97095-08045-00)
- 2 x Plates (63V-44328-01-00)
Installation Notes
- Disconnect the battery and ensure the engine is off and cool.
- Drain the gearcase oil from the lower unit.
- Remove the bolts securing the lower unit (gearcase) to the upper casing and carefully lower it. Disconnect the shift linkage if necessary.
- Unbolt and remove the old water pump housing assembly from the driveshaft. Take note of the orientation of all parts.
- Clean the mounting surfaces and inspect the driveshaft for wear or corrosion.
- Install the new woodruff key, impeller, plates, and seals from the kit onto the driveshaft.
- Seat the new housing over the impeller, ensuring the impeller vanes are oriented correctly (typically by turning the driveshaft in its normal direction of rotation).
- Lightly grease the new bolts and tighten the housing to the manufacturer's specified torque.
- Reinstall the lower unit, reconnecting the shift linkage, and refilling the gearcase oil.
- Start the engine in a water supply (using flushing muffs or in the water) and verify a strong, consistent stream of water from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if this water pump kit will fit my engine?
This kit is designed for specific Yamaha 15HP and 20HP four-stroke models from 2006-onwards. The most reliable method is to cross-reference your engine's model and year against the compatibility table provided. For models like the F9.9 and F13.5, please verify your existing OEM part number is 6AH-W0078-00-00 before purchasing.
What are the signs of a worn or failing water pump impeller?
Common symptoms include the engine overheating at idle or low speeds, a weak or inconsistent water stream from the "tell-tale" outlet, or a complete lack of water flow. Visible damage to the old impeller, such as cracked, brittle, or missing vanes, also indicates it's time for a replacement.
How often should I replace my water pump impeller?
As a general maintenance guideline, it is recommended to inspect and/or replace the water pump impeller every 1 to 2 years or every 100-200 hours of operation, whichever comes first. This interval can vary depending on usage conditions (e.g., saltwater vs. freshwater, sandy/silty water).
Is this OEM or Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
What are the shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
What is the warranty & do you accept returns?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in 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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