Water Pump Impeller Repair Kit – Fits Yamaha 9.9HP/15HP Outboard (Replaces 63V-W0078-01)
Water Pump Impeller Repair Kit – Fits Yamaha 9.9HP/15HP Outboard (Replaces 63V-W0078-01) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Water Pump Impeller Repair Kit – Fits Yamaha 9.9HP/15HP Outboard (R...
Water Pump Impeller Repair Kit – Fits Yamaha 9.9HP/15HP Outboard (Replaces 63V-W0078-01) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Repair Kit is designed to service Yamaha 9.9HP and 15HP two-stroke outboard engines from 1996–2009 and 9.9HP/15HP four-stroke models from 1998–2006. It contains all necessary components to restore your engine's cooling system performance.
It serves as a direct replacement for Yamaha OEM part numbers 63V-W0078-00, 63V-W0078-01, 63V-W0078-02, 63V-W0078-03, and the latest 63V-W0078-04-00, as well as Sierra equivalents 18-3148 and 18-3411.
- Installs in the lower unit (gearcase).
- Engineered for direct-fit replacement.
- Includes impeller, housing, plate, seals, and hardware.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Superseded By | Notes |
|---|---|---|---|
| Yamaha | 63V-W0078-00-00 | 63V-W0078-01-00 | Original part number. |
| Yamaha | 63V-W0078-01-00 | 63V-W0078-02-00 | This kit is a direct replacement. |
| Yamaha | 63V-W0078-02-00 | 63V-W0078-03-00 | This kit is a direct replacement. |
| Yamaha | 63V-W0078-03-00 | 63V-W0078-04-00 | This kit is a direct replacement. |
| Sierra | 18-3148 | Aftermarket cross-reference. | |
| Sierra | 18-3411 | Aftermarket cross-reference. |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure correct fitment.
This kit is designed for a range of two-stroke and four-stroke Yamaha outboards.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 9.9 | 9.9 | 2-Stroke | 1996–2009 | 63V-W0078-01 | Superseded by 63V-W0078-04-00 |
| Yamaha | 15 | 15 | 2-Stroke | 1996–2009 | 63V-W0078-01 | Superseded by 63V-W0078-04-00 |
| Yamaha | F9.9 | 9.9 | 4-Stroke | 2005–2006 | 63V-W0078-01 | Superseded by 63V-W0078-04-00 |
| Yamaha | F15 | 15 | 4-Stroke | 1998–2005 | 63V-W0078-01 | Superseded by 63V-W0078-04-00 |
| Yamaha | T9.9 | 9.9 | 4-Stroke | 1996–2006 | 63V-W0078-01 | High Thrust model, superseded by 63V-W0078-04-00 |
| Yamaha | FT9.9 | 9.9 | 4-Stroke | 1996–2006 | 63V-W0078-01 | High Thrust model, superseded by 63V-W0078-04-00 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Lower Unit/Gearcase
- Connection
- Direct Mount
- Housing Material
- Composite/Plastic with Metal Components
- Housing Color
- Black/Silver
- Dimensions
- 12.5" L x 11.5" W x 6.5" H
- Fitting Type
- Direct Replacement
- Warranty
- Manufacturer Dependent
- Other Technical Attributes
- Simple design, easy installation
What’s in the Box
- 1 x Insert, Cartridge (63V-44322-00-00)
- 1 x Outer Plate, Cartridge (63V-44323-00-00)
- 1 x Impeller (63V-44352-01-00)
- 1 x Water Seal 2 (647-44366-00-00)
- 1 x Key, Woodruff (664-44338-00-00)
- 4 x Bolt, Hexagon (97080-08045-00)
- 1 x O-Ring (93210-44704) - Note: Included in kit but not pictured by all sources.
Installation Notes
- Disconnect the battery and spark plug leads for safety.
- Shift the outboard into neutral and remove the lower unit (gearcase) bolts.
- Carefully separate the lower unit from the upper casing.
- Locate and unbolt the water pump housing cover.
- Remove the old impeller, housing, gaskets, and other components from the kit. Note their orientation.
- Clean all mating surfaces thoroughly, removing any old gasket material or corrosion.
- Install the new components from the kit in the reverse order of removal. Lightly grease the impeller.
- Ensure the impeller key is properly seated and rotate the driveshaft clockwise while sliding the housing down.
- Torque the housing bolts to the manufacturer's specifications.
- Reinstall the lower unit, ensuring the water tube and shift shaft align correctly.
- Reconnect the battery and test the engine on a water supply to verify proper cooling system function.
Troubleshooting & FAQ
How do I know if this kit fits my engine?
The surest way is to match your engine's model and year to our compatibility chart. You can also cross-reference your existing part number with those listed in the Part Number Matrix.
What are the signs of a failing water pump impeller?
Common signs include the engine overheating at idle or low speeds, a weak or non-existent "telltale" water stream, and a melted/distorted pump housing. Visually, the old impeller may have cracked, brittle, or missing vanes.
How often should I replace my water pump impeller?
As a preventative maintenance best practice, most manufacturers recommend replacing the impeller every 100-200 operating hours or at least once per season, especially for boats used in saltwater.
My old part number isn't an exact match. Will this still work?
Yes. Manufacturers often update (supersede) part numbers over time. This kit (replaces 63V-W0078-01) is the modern equivalent for all previous versions listed in the compatibility table, offering the same fit and function.
Is the O-Ring (93210-44704) definitely included?
Yes, our kits include the O-ring. Some OEM diagrams or older packages did not picture it, but it is a required component for a complete seal and is included in your purchase.
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 and specifications against your original part before ordering. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement part, not an OEM component.
- Professional installation is highly recommended for safety and optimal 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 quality control.
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