Water Pump Repair Kit – Fits Yamaha 6–15 HP (Replaces 63V-44301-00, 63V-W0078-00)
Water Pump Repair Kit – Fits Yamaha 6–15 HP (Replaces 63V-44301-00, 63V-W0078-00) 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 Repair Kit – Fits Yamaha 6–15 HP (Replaces 63V-44301-00,...
Water Pump Repair Kit – Fits Yamaha 6–15 HP (Replaces 63V-44301-00, 63V-W0078-00) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Repair Kit – Fits Yamaha 6–15 HP (Replaces 63V-44301-00, 63V-W0078-00) provides all essential components to restore your engine’s cooling system. It is designed for Yamaha 4-Stroke engines including 6 HP, 8 HP, 9.9 HP, 13.5 HP, and 15 HP models (1998–2008), as well as 2-Stroke 9.9 HP and 15 HP models (1998–2008).
This kit serves as a direct replacement for Yamaha part numbers in the 63V-W0078-00 through 63V-W0078-04 series, and interchanges with Sierra 18-3356/18-3412, HJ YHJB-63V, Mallory 9-43254, and Parsun PAF15-06060001.
- Installs in the lower unit gearcase to restore water circulation.
- Includes the impeller, cartridge, plate, seals, and hardware for a complete overhaul.
- Engineered to match OEM specifications for fit and function.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 63V-W0078-00-00 | Original part number. |
| Yamaha | 63V-W0078-01-00 | Superseded. |
| Yamaha | 63V-W0078-02-00 | Superseded. |
| Yamaha | 63V-W0078-03-00 | Superseded. |
| Yamaha | 63V-W0078-04-00 | Latest OEM revision. |
| Sierra | 18-3356 | Aftermarket equivalent. |
| Sierra | 18-3412 | Aftermarket equivalent kit. |
| HJ | YHJB-63V | Aftermarket equivalent. |
| Mallory Marine | 9-43254 | Aftermarket equivalent. |
| Parsun | PAF15-06060001 | Aftermarket equivalent. |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
This kit is designed for a range of Yamaha 2-stroke and 4-stroke outboard motors.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F9.9 | 9.9 | 4-Stroke | 1998–2008 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
| Yamaha | F13.5 | 13.5 | 4-Stroke | 2002–2007 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
| Yamaha | F15 | 15 | 4-Stroke | 1998–2007 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
| Yamaha | F6 | 6 | 4-Stroke | Up to 2008 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
| Yamaha | F8 | 8 | 4-Stroke | Up to 2008 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
| Yamaha | 9.9F | 9.9 | 2-Stroke | 1998–2008 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
| Yamaha | 13.5AWH | 13.5 | 2-Stroke | 2002–2007 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
| Yamaha | 15F, 15FMH, 15FMHS | 15 | 2-Stroke | 1998–2007 | 63V-W0078-01-00 | Superseded by 63V-W0078-04-00 |
Technical Specs
- Product Type
- Water Pump Repair Kit
- Installation Location
- Lower Unit/Gearcase
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 Damper 2 (647-44366-00-00)
- 1 x Key, Woodruff (664-44338-00-00)
- 4 x Bolt (97095-08045-00)
- 1 x O-ring (93210-44704)
Installation Notes
- Disconnect the battery and shift the outboard into neutral.
- Remove the bolts securing the lower unit (gearcase) to the engine.
- Carefully lower the gearcase, being mindful of the shift shaft linkage.
- Unbolt and remove the old water pump housing assembly.
- Clean the mounting surfaces and inspect the housing for wear, replacing if necessary.
- Install the new cartridge, impeller, key, and plate from the kit. Ensure the impeller vanes are oriented correctly.
- Lightly grease the interior of the housing and reinstall it with the new bolts and seals provided.
- Re-attach the lower unit to the engine, ensuring the driveshaft and shift shaft align properly.
- Once assembled, start the engine in water and verify a strong, consistent stream from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if my water pump is failing?
Common signs of a failing water pump include the engine overheating at idle or low speeds, a weak or intermittent water stream from the tell-tale (peephole) outlet, or a completely dry/brittle impeller found during inspection.
What is the recommended replacement interval for this kit?
For preventative maintenance and to ensure engine reliability, most marine mechanics recommend replacing the water pump impeller and associated seals every 1 to 2 years or every 100-200 hours of engine use, whichever occurs first.
Does this kit include the water pump housing?
No, this is a repair kit containing the wearable internal components (impeller, plates, seals, hardware). The water pump housing (Yamaha P/N 63V-44301-00-00) is a separate component and should be inspected for melting, scoring, or warping and replaced if damaged.
Why are there multiple part numbers for this one kit?
Manufacturers like Yamaha often revise and update parts over time for design improvements, material changes, or to consolidate previous versions. This kit is built to the latest specification and directly replaces the entire 63V-W0078 series, from -00 to the current -04 revision.
Is this an OEM part or an aftermarket one?
This listing is for an aftermarket replacement, not an original equipment manufacturer (OEM) part. It is built to meet or exceed OEM-level specifications using comparable materials. Our parts are manufactured in an ISO 9002 certified facility and are batch-inspected for quality and consistency.
How fast is shipping and what does it cost?
We ship worldwide quickly, with typical transit times of 5–15 days to most regions. Standard shipping is free for most orders. Expedited shipping options, where available, will be presented at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal operating conditions. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard return window for unused items in their original condition. See our full policy page or contact us for instructions.
Safety & Important Info
- Always verify the product images and specifications against your original part before installation. If anything differs—even if your model is listed as compatible—do not purchase or install the part.
- This is an aftermarket replacement component, not an OEM part. Brand names and part numbers are used for reference purposes only.
- For safety and optimal performance, professional installation by a qualified marine mechanic is highly recommended.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world performance and durability.
- Fast Global Fulfillment — With free standard delivery to most regions, you can expect your parts in 5–15 days.
- Manufacturer-Direct Value — By working directly with our manufacturing partners, we offer fair pricing without compromising on materials or quality control.
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