Water Pump Repair Kit – Fits Yamaha F15, F20, F9.9 4-Stroke (Replaces 6AH-W0078-00, Sierra 18-3479, 18-3484)
Water Pump Repair Kit – Fits Yamaha F15, F20, F9.9 4-Stroke (Replaces 6AH-W0078-00, Sierra 18-3479, 18-3484) is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
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.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Water Pump Repair Kit – Fits Yamaha F15, F20, F9.9 4-Stroke (Replac...
Water Pump Repair Kit – Fits Yamaha F15, F20, F9.9 4-Stroke (Replaces 6AH-W0078-00, Sierra 18-3479, 18-3484) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Repair Kit – Fits Yamaha F15, F20, F9.9 4-Stroke Outboards (Replaces 6AH-W0078-00) is designed for a range of Yamaha 4-Stroke outboards, including F9.9, F13.5, F15, and F20 models manufactured between 2007 and 2017. It is compatible with multiple F-series models such as the F15C and F20B.
The kit serves as a direct replacement for Yamaha OEM parts 6AH-W0078-00-00, 6AH-W0078-01-00, and 6AH-W0078-02-00. It also interchanges with Sierra aftermarket kits 18-3479 and 18-3484 (with housing).
- Engineered for direct OEM replacement installation.
- Includes all components required for a complete water pump service.
- Features a durable plastic/composite housing.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 6AH-W0078-00-00 | |
| Yamaha | 6AH-W0078-01-00 | |
| Yamaha | 6AH-W0078-02-00 | |
| Sierra | 18-3479 | |
| Sierra | 18-3484 | with housing |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha engines, please verify that your model and year fall within the specified ranges. Check the notes column for specific model codes.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F15C | 15 | 4-Stroke | 2008–2017 | 6AH-W0078-00-00 | F15CEHL, F15CEHS, F15CMHL, F15CMHS models |
| Yamaha | F15L | 15 | 4-Stroke | 2007–2017 | 6AH-W0078-00-00 | F15LEHA, F15LMHA models |
| Yamaha | F20B | 20 | 4-Stroke | 2007–2017 | 6AH-W0078-00-00 | F20BEHPL, F20BEPL, F20BMHL, F20BMHS models |
| Yamaha | F20L | 20 | 4-Stroke | 2007–2017 | 6AH-W0078-00-00 | F20LMHA, F20LPA, F20LPHA models |
| Yamaha | F9.9 | 9.9 | 4-Stroke | 2009–2016 | 6AH-W0078-00-00 | 6CA1-6AC9 models |
| Yamaha | F13.5 | 13.5 | 4-Stroke | 2007–2009 | 6AH-W0078-00-00 | 6AF1-6AF3 models |
Technical Specs
- Product Type
- Outboard Water Pump Repair Kit
- Installation
- Direct OEM replacement
- Housing Material
- Plastic/Composite
- Housing Color
- Black
- Warranty
- Varies by manufacturer
- Other Technical Attributes
- Includes all components required for complete water pump service
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 Pin (93604-12M07-00)
- 4 x Bolt with Washer (97095-08045-00)
- 2 x Plate (63V-44328-01-00)
Installation Notes
- Disconnect the spark plug leads and the battery cables for safety.
- Shift the outboard into neutral and remove the lower unit mounting bolts. Carefully separate the lower unit from the upper casing.
- Unbolt and remove the old water pump housing to access the impeller and other components.
- Thoroughly clean the mounting surfaces, removing any old gasket material or corrosion.
- Install the new woodruff key, impeller, plates, and seals as provided in the kit. Ensure the impeller vanes are oriented correctly during installation.
- Assemble the new water pump housing and torque the bolts to the manufacturer's specifications.
- Apply a marine-grade sealant to the new gaskets where required and reinstall the lower unit.
- Once assembled, test the engine in a water-filled test tank or with a water flusher to confirm a strong and steady "tell-tale" stream before returning to open water.
Troubleshooting & FAQ
How do I know if this water pump kit will fit my Yamaha outboard?
This kit is designed for specific Yamaha models and years. Please consult the "Engine & Model Compatibility" table on this page. Cross-reference your engine's model number, horsepower, and year to ensure a match. Verifying the OEM part number (6AH-W0078-00) against your service manual is the most reliable method.
What are the signs of a failing water pump?
Common symptoms of a worn or failed water pump impeller include the engine overheating at idle or low speeds, a weak or intermittent "tell-tale" water stream from the exhaust port, or steam coming from the exhaust. Regular inspection is recommended.
How often should I replace my outboard's water pump impeller and kit?
For preventative maintenance, it is recommended to inspect the impeller annually and replace the entire water pump repair kit every 2-3 years or 200-300 hours of operation. Service intervals can be shorter in saltwater or silty/sandy water conditions.
Does this kit include the water pump housing?
Yes, this is a complete repair kit that includes the water pump housing (OEM ref 6AH-44311-00-00) along with the impeller, gaskets, plates, and all necessary hardware for a full service.
Is there a difference between the Sierra 18-3479 and 18-3484 kits mentioned?
Yes. Both are compatible aftermarket cross-references. The Sierra 18-3484 is a complete kit that includes the housing, just like this one. The Sierra 18-3479 is a basic kit that typically does not include the housing. This product is a complete solution for a full water pump replacement.
OEM vs. 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.
Shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & 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.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
