Water Pump Impeller Kit – Fits Yamaha F8, F9.9, F20, F25, FT8, FT9.9 (Replaces 61N-W0078-11-00)
Water Pump Impeller Kit – Fits Yamaha F8, F9.9, F20, F25, FT8, FT9.9 (Replaces 61N-W0078-11-00) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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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.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Water Pump Impeller Kit – Fits Yamaha F8, F9.9, F20, F25, FT8, FT9....
Water Pump Impeller Kit – Fits Yamaha F8, F9.9, F20, F25, FT8, FT9.9 (Replaces 61N-W0078-11-00) is backordered and will ship as soon as it is back in stock.
Product Details
This comprehensive Water Pump Impeller Kit – Fits Yamaha F8, F9.9, F20, F25, FT8, FT9.9 Outboards (Replaces 61N-W0078-11-00) provides all necessary components to restore your engine's cooling system. It is designed for a range of Yamaha 4-stroke models from 1998 to 2017+ (including F20A/D, F25A/D, FT8D/G, and FT9.9G/J) and select 2-stroke models like the 30G and C30.
This kit serves as a direct replacement for Yamaha OEM part numbers 61N-W0078-10-00, 61N-W0078-11-00, 61N-W0078-13-00, and 61N-W0078-14-00, as well as Sierra part 18-3432, ensuring broad compatibility and reliable performance.
- Installation Location: Mounts in the lower unit.
- Core Components: Includes the pump housing, a complete impeller assembly, and all required hardware.
- Engine Health: Restores proper cooling pressure to prevent overheating and potential engine damage.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 61N-W0078-10-00 | Superseded |
| Yamaha | 61N-W0078-11-00 | Primary replacement number |
| Yamaha | 61N-W0078-13-00 | Superseded |
| Yamaha | 61N-W0078-14-00 | Latest supersession |
| Sierra | 18-3432 | Aftermarket cross-reference |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is verified to fit the following Yamaha outboard models.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F20AE | 20 | 4-Stroke | 2003–2006 | 61N-W0078-11 | |
| Yamaha | F20DET | 20 | 4-Stroke | 2011–2015 | 61N-W0078-11 | |
| Yamaha | F25A, AE, AM, AW, EL, MH | 25 | 4-Stroke | 1998–2009 | 61N-W0078-11 | |
| Yamaha | F25DE, DM, MH | 25 | 4-Stroke | 2009–2015 | 61N-W0078-11 | 6BT1-6BT8 |
| Yamaha | FT8D/FT8G | 8 | 4-Stroke | 2001–2014 | 61N-W0078-11 | |
| Yamaha | FT9.9G | 9.9 | 4-Stroke | 2008–2012 | 61N-W0078-11 | |
| Yamaha | FT9.9J | 9.9 | 4-Stroke | 2013+ | 61N-W0078-11 | |
| Yamaha | 30G | 30 | 2-Stroke | 1993–2000 | 61N-W0078-11 | |
| Yamaha | C30 | 30 | 2-Stroke | 1993–1997 | 61N-W0078-11 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Lower Unit
- Housing Material
- Aluminum
- Warranty
- Manufacturer's Standard
- Other Technical Attributes
- Includes pump housing and complete impeller assembly
What’s in the Box
- 1 x Pump Body (61N-44311-00-00/61N-44311-01-00)
- 1 x Impeller (6H4-44352-00/6H4-44352-01/6H4-44352-02)
- 1 x Cartridge Insert (63V-44322-00-00)
- 1 x Water Seal Damper (6L2-44367-00-00)
- 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)
- 4 x Bolts (97095-08045-00)
- 2 x Plates (63V-44328-01-00)
Installation Notes
- Disconnect the battery and shift the outboard into neutral.
- Place a drain pan under the lower unit and remove the gearcase oil drain screw to empty the oil.
- Remove the bolts securing the lower unit (gearcase) to the upper casing and carefully lower it.
- Unbolt and remove the old water pump housing to access the impeller. Note the orientation of the old parts.
- Clean the mounting surfaces and remove the old impeller, key, and gaskets.
- Install the new woodruff key, impeller (turn clockwise when seating), and gaskets/seals from the kit.
- Install the new pump housing, insert, and outer plate, ensuring seals are correctly seated.
- Tighten the housing bolts to the manufacturer's specified torque.
- Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are aligned.
- Refill the gearcase with fresh oil, reinstall the battery, and start the engine on a water supply to verify a strong tell-tale stream.
Troubleshooting & FAQ
How do I confirm this kit fits my Yamaha outboard?
Check your engine’s model number and year against the "Engine & Model Compatibility" table. The model number is usually on a sticker on the transom clamp bracket. This kit fits a specific range of F-series 4-strokes and older 2-strokes, so confirming your exact model is crucial.
What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent "tell-tale" water stream, an engine overheat alarm, or steam from the exhaust. Reduced top-end speed can also be a sign of the engine limiting RPM due to high temperatures.
How often should the water pump impeller be replaced?
As a preventative maintenance item, it's recommended to replace the impeller every 1-2 years or every 100-200 hours of use, whichever comes first. Usage in saltwater or sandy/silty conditions may require more frequent changes.
My engine is overheating, but the tell-tale is streaming. Could it still be the impeller?
Yes. A strong tell-tale stream indicates some water flow but doesn't guarantee sufficient pressure and volume to cool the entire engine block, especially at higher RPMs. A worn impeller can lose efficiency under load, leading to overheating even with a visible water stream at idle.
Is it necessary to replace the entire kit, or can I just change the impeller?
While just replacing the impeller is possible, it is highly recommended to replace the full kit. The included housing, wear plates, and seals wear down over time, and a new impeller in a worn housing will perform poorly and have a much shorter lifespan.
What is the difference between this aftermarket kit and an OEM one?
This is an aftermarket replacement part, not an OEM (Original Equipment Manufacturer) component. It is engineered to meet or exceed OEM specifications using comparable materials and construction methods. Our parts are produced in an ISO 9002 certified facility and undergo batch inspections to ensure quality and fitment, offering a reliable alternative at a better value.
How fast do you ship and what are the costs?
We ship worldwide, with most orders arriving in 5–15 days. Standard shipping is free for most destinations. Expedited shipping options, if available for your location, will be presented at checkout with their respective costs.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. Should you encounter a problem, please contact our support team with your order number. We accept returns on unused items in their original packaging within our standard return period. Please see our full policy page or contact us for detailed 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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