Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP (Replaces 63V-W0078-01, 18-3412)
Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP (Replaces 63V-W0078-01, 18-3412) 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 9.9/15 HP (Replaces 63V-W0078...
Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP (Replaces 63V-W0078-01, 18-3412) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP (Replaces 63V-W0078-01) is engineered for Yamaha 4-stroke F9.9C (1998–2008) and F15A (1998–2007) outboards, and also covers various 2-stroke 9.9 HP and 15 HP models from 1996 through 2000, plus select newer engines from 2004 onward.
This kit serves as a direct interchange for Yamaha part numbers 63V-W0078-01-00, 63V-W0078-00-00, 63V-W0078-02-00, 63V-W0078-03-00, and aftermarket cross-references Sierra 18-3412, Sierra 18-3433, and GLM 12066.
- Designed for direct, hassle-free installation to restore cooling system performance.
- Includes a complete impeller, housing inserts, and all necessary gaskets and hardware for a full service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 63V-W0078-01-00 |
| Yamaha | 63V-W0078-00-00 |
| Yamaha | 63V-W0078-02-00 |
| Yamaha | 63V-W0078-03-00 |
| Sierra | 18-3412 |
| Sierra | 18-3433 |
| GLM | 12066 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is designed for a wide range of Yamaha outboard motors. Please check your specific model and year against the tables below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 9.9MLHY/MSHY | 9.9 | 2-Stroke | 2000 | 63V-W0078-01 | |
| Yamaha | 15MLHY/MSHY | 15 | 2-Stroke | 2000 | 63V-W0078-01 | |
| Yamaha | 9.9MLHX/MSHX | 9.9 | 2-Stroke | 1999 | 63V-W0078-01 | |
| Yamaha | 15MLHX/MSHX | 15 | 2-Stroke | 1999 | 63V-W0078-01 | |
| Yamaha | 9.9MLHW/MSHW | 9.9 | 2-Stroke | 1998 | 63V-W0078-01 | |
| Yamaha | 15MLHW/MSHW | 15 | 2-Stroke | 1998 | 63V-W0078-01 | |
| Yamaha | 9.9ELHV/ELRV/ESHV/MLHV/MSHV | 9.9 | 2-Stroke | 1997 | 63V-W0078-01 | |
| Yamaha | 15ELHV/ESHV/MLHV/MSHV | 15 | 2-Stroke | 1997 | 63V-W0078-01 | |
| Yamaha | 9.9ELHU/ELRU/ESHU/MLHU/MSHU | 9.9 | 2-Stroke | 1996 | 63V-W0078-01 | |
| Yamaha | 15ELHU/ELRU/ESHU/MLHU/MSHU | 15 | 2-Stroke | 1996 | 63V-W0078-01 | |
| Yamaha | 9.9 HP | 9.9 | 2-Stroke | 2004+ | 63V-W0078-01 | |
| Yamaha | 15 HP | 15 | 2-Stroke | 2004+ | 63V-W0078-01 |
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F9.9C/CE/CM/CW/MH | 9.9 | 4-Stroke | 1998–2008 | 63V-W0078-01 | |
| Yamaha | F15A/AE/AM/EL/MH | 15 | 4-Stroke | 1998–2007 | 63V-W0078-01 | |
| Yamaha | F9.9 HP | 9.9 | 4-Stroke | 2005 | 63V-W0078-01 | |
| Yamaha | T9.9 HP | 9.9 | 4-Stroke | 2005+ | 63V-W0078-01 | |
| Yamaha | FT9.9D/DE/DM/DW | 9.9 | 4-Stroke | 1999–2008 | 63V-W0078-01 | |
| Yamaha | FT9.9D/DEP/PLR/TR | 9.9 | 4-Stroke | 2000–2002 | 63V-W0078-01 | |
| Yamaha | T9.9 | 9.9 | 4-Stroke | 2005–2006 | 63V-W0078-01 | Model: 6AF1-6AF3 |
| Yamaha | F13.5AE/AM | 13.5 | 4-Stroke | 2002–2007 | 63V-W0078-01 | Model: 66M-66M7 |
| Yamaha | F13.5AEP | 13.5 | 4-Stroke | 2005–2007 | 63V-W0078-01 |
Technical Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Direct replacement
- Fitting Type
- Direct fit
- Included Components
- Includes complete impeller assembly and all necessary gaskets and hardware
What’s in the Box
- 1 x Impeller (63V-44352-01-00)
- 1 x Woodruff Key (664-44338-00-00)
- 1 x Outer Plate (63V-44323-00)
- 4 x Bolts (97095-08045-00)
- 1 x Cartridge Insert (63V-44322-00)
- 1 x Water Seal Damper (647-44366-00-00)
- 1 x O-ring (93210-44704)
Installation Notes
- Disconnect the battery and shift the outboard into neutral. Place a drain pan under the lower unit.
- Remove the bolts securing the lower unit (gearcase) to the upper casing and carefully lower it.
- Unbolt and remove the water pump housing cover to expose the old impeller.
- Take note of the old impeller's blade direction, then remove the impeller, gaskets, and wear plate.
- Clean all surfaces thoroughly, removing any old gasket material or debris.
- Install the new water seal, Woodruff key, wear plate, and gaskets.
- Slide the new impeller onto the driveshaft while turning the shaft clockwise to seat the vanes correctly inside the housing cup.
- Reinstall the housing cover, applying a marine-grade sealant to the bolt threads and tightening them to the manufacturer's recommended torque.
- Reattach the lower unit, ensuring the driveshaft and water tube align correctly. Reinstall and tighten bolts.
- Once fully assembled, use a flush attachment to run the engine with a steady water supply and verify a strong, consistent stream from the tell-tale port.
Troubleshooting & FAQ
How do I know if this kit fits my Yamaha engine?
The most reliable method is to verify your engine's model and year against our compatibility tables. Additionally, you can cross-reference the part numbers in the 'Part Number Matrix' with the existing part or your service manual.
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 "tell-tale" outlet, or a dry, crumbly appearance of the old impeller upon inspection.
How often should the water pump impeller be replaced?
As a preventative maintenance best practice, inspect your impeller annually and plan for a replacement every 1-2 years or every 100-200 hours of use. Intervals should be shorter if operating frequently in saltwater, or sandy/silty conditions.
Is the included Woodruff key important?
Yes, the Woodruff key is critical. It locks the impeller to the driveshaft, ensuring it spins correctly. Always replace the key when you replace the impeller to prevent slippage and pump failure.
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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