Water Pump Impeller Kit – Fits Yamaha 4-Stroke 9.9-30HP (Replaces 61N-W0078-11-00, 18-3432)
Water Pump Impeller Kit – Fits Yamaha 4-Stroke 9.9-30HP (Replaces 61N-W0078-11-00, 18-3432) 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 4-Stroke 9.9-30HP (Replaces 61N-W0078-11-00, 18-3432) is backordered and will ship as soon as it is back in stock.
Product Details
This comprehensive Water Pump Impeller Kit – Fits Yamaha 9.9-30HP 4-Stroke Outboards (Replaces 61N-W0078-11-00) is designed for routine maintenance or repair of the engine's cooling system. It is primarily intended for Yamaha F25 (25HP) 4-stroke outboards but also offers compatibility with F9.9, F15, F20, and F30 models.
This kit serves as a direct replacement for Yamaha part number 61N-W0078-11-00 and Sierra 18-3432, ensuring a precise fit and reliable performance.
- Installs in the lower unit (gearcase) to restore cooling system efficiency.
- Engineered as a direct-fit replacement for straightforward installation.
- Meets or exceeds OEM quality standards for durability and function.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 61N-W0078-11-00 |
| Sierra | 18-3432 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is designed for select Yamaha 4-stroke outboard models.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | F25 | 25 | 4-Stroke | 61N-W0078-11-00 | |
| Yamaha | F9.9 | 9.9 | 4-Stroke | 61N-W0078-11-00 | |
| Yamaha | F15 | 15 | 4-Stroke | 61N-W0078-11-00 | |
| Yamaha | F20 | 20 | 4-Stroke | 61N-W0078-11-00 | |
| Yamaha | F30 | 30 | 4-Stroke | 61N-W0078-11-00 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Lower Unit / Gearcase
- Fitting Type
- Direct Fit
- Other Technical Attributes
- OEM Quality Replacement
What’s in the Box
- 1 x Cartridge Insert (63V-44322-00-00)
- 1 x Water Seal Damper 3 (6L2-44367-00-00)
- 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)
- 4 x Bolts (97095-08045-00)
- 2 x Plates (63V-44328-01-00)
Installation Notes
- Disconnect the battery and shift the outboard into neutral.
- Remove the lower unit (gearcase) by unbolting it from the midsection. This may also require disconnecting the shift linkage.
- Once the lower unit is removed, locate and unbolt the water pump housing.
- Carefully remove the old impeller, O-rings, plates, and seals. Clean the housing thoroughly to remove any debris or corrosion.
- Install the new components from the kit in the reverse order of removal, ensuring all parts are correctly seated. Lightly grease the new impeller.
- Reinstall the water pump housing, torquing the bolts to the manufacturer's specification.
- Reattach the lower unit to the engine, reconnecting any linkages, and test the engine in the water to verify proper cooling.
Troubleshooting & FAQ
How can I confirm this kit fits my specific engine model year?
While this kit covers a broad range of Yamaha 9.9-30HP 4-stroke engines, year ranges are not always specified by manufacturers. The best way to confirm is by matching the OEM part number (61N-W0078-11-00) to your service manual or an online parts diagram for your specific engine serial number.
What are the signs of a failing water pump impeller?
Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent stream of water from the "telltale" outlet, and in severe cases, an engine alarm. The impeller is a rubber component that can become brittle, cracked, or worn over time, reducing its ability to pump water.
How often should I replace my water pump impeller?
As a general maintenance rule, it's recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of use, whichever comes first. This interval can be shorter if you frequently operate in sandy or silty water.
Is there a difference in performance between this kit and the OEM version?
This aftermarket kit is engineered to meet or exceed original equipment manufacturer (OEM) specifications. It provides a comparable level of performance and durability under normal operating conditions, offering a reliable and cost-effective alternative to the OEM part.
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.
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