Water Pump Impeller Repair Kit – Fits Yamaha 6–30 HP Outboards (Replaces Yamaha 63V-W0078-00/01, Sierra 18-3412/18-3433)
Water Pump Impeller Repair Kit – Fits Yamaha 6–30 HP Outboards (Replaces Yamaha 63V-W0078-00/01, Sierra 18-3412/18-3433) is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Repair Kit – Fits Yamaha 6–30 HP Outboards (Rep...
Water Pump Impeller Repair Kit – Fits Yamaha 6–30 HP Outboards (Replaces Yamaha 63V-W0078-00/01, Sierra 18-3412/18-3433) is backordered and will ship as soon as it is back in stock.
Product Details
This water pump impeller repair kit is intended to service the cooling-water pump on selected Yamaha outboard engines. It is listed for certain Yamaha 2-stroke applications from 6–30 HP and selected 4-stroke applications from F6–F15. Fitment depends on the exact engine model, year, stroke type, and existing water-pump configuration.
The kit is listed as a replacement for Yamaha references 63V-W0078-00 and 63V-W0078-01, as well as Sierra references 18-3412 and 18-3433. Compare the original pump components and part numbers before ordering; horsepower alone does not establish fitment.
- Designed as a direct replacement for compatible water-pump assemblies.
- Includes a pump housing, impeller, cartridge components, seal damper, key, and mounting bolts as listed below.
- Suitable for water-pump service when the listed components match the original assembly.
Part Number Matrix
These references are provided for identification and cross-reference purposes. Confirm the exact application before installation.
| Brand | Part Number |
|---|---|
| Yamaha | 63V-W0078-00-00 |
| Yamaha | 63V-W0078-01-00 |
| Yamaha | 63V-W0078-02-00 |
| Yamaha | 63V-W0078-03-00 |
| Yamaha | 63V-W0078-04-00 |
| Sierra | 18-3412 |
| Sierra | 18-3433 |
| GLM | 12087 |
| GLM | 12033 |
| GLM | 12865 |
| GLM | 12517 |
| GLM | 12066 |
Engine & Model Compatibility
The applications below represent the listed compatibility range. Always verify the complete model designation, production year, stroke type, and serial-number range against the original engine and pump assembly.
| Brand | Model or Horsepower | Rated HP | Stroke | Years | Reference | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 9.9 and 15 | 9.9, 15 | 2-Stroke | 1996–2013 | 63V-W0078-00-00 | Verify the exact model designation and serial range. |
| Yamaha | 20, 25, and 30 | 20, 25, 30 | 2-Stroke | Various | 63V-W0078-00-00 | Confirm the pump configuration before ordering. |
| Brand | Model | Rated HP | Stroke | Years | Reference | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F6 | 6 | 4-Stroke | 2001–2008 | 63V-W0078-00-00 | Verify the exact model and serial range. |
| Yamaha | F8, T8 | 8 | 4-Stroke | 2001–2019 | 63V-W0078-00-00 | Verify the exact model and serial range. |
| Yamaha | F9.9, F9.9-2 | 9.9 | 4-Stroke | 2007–2013 | 63V-W0078-00-00 | Verify the exact model and serial range. |
| Yamaha | FT9.9, T9.9, T9.9-2 | 9.9 | 4-Stroke | 2005–2013 | 63V-W0078-00-00 | Verify the exact model and serial range. |
| Yamaha | F15 | 15 | 4-Stroke | 2001–2013 | 63V-W0078-00-00 | Verify the exact model and serial range. |
Technical Specifications
- Product Type
- Water pump impeller repair kit with housing
- Installation
- Direct replacement for compatible assemblies
- Housing Material
- Nylon
- Housing Color
- Black
- Impeller Material
- Neoprene
- Other Components
- Stainless steel wear plate and liner, cartridge components, seal damper, key, and mounting hardware
What's in the Box
- 1 × Pump Housing, 63V-44301-00
- 1 × Water Pump Impeller, 63V-44352-01-00
- 1 × Cartridge Insert, 63V-44322-00-00
- 1 × Cartridge Outer Plate, 63V-44323-00-00
- 1 × Water Seal Damper, 647-44366-00-00
- 1 × Woodruff Key, 63V-44338-00-00
- 4 × Bolts, 97080-08045-00
Installation Notes
- Review the service information for the specific engine before beginning work.
- Disconnect the battery where applicable and remove the engine cover.
- Place the gear selector in neutral.
- Drain the lower-unit gear lubricant if required by the service procedure.
- Remove the fasteners securing the lower unit and carefully separate it from the engine.
- Remove the water-pump housing and inspect the shaft, keyway, housing, plates, and mating surfaces.
- Remove the old impeller, gaskets, plates, and seals. Clean the mating surfaces thoroughly.
- Install the replacement components in the correct order. Ensure the impeller key and vanes are positioned correctly.
- Reassemble the pump and tighten fasteners to the engine manufacturer's specifications.
- Reattach the lower unit and refill the gear lubricant according to the applicable service procedure.
- Run the engine only in water or with an appropriate flushing device, then confirm a steady tell-tale stream and normal operating temperature.
Troubleshooting & FAQ
How do I confirm that this kit fits my Yamaha outboard?
Check the complete engine model, horsepower, year, stroke type, and serial-number range. Compare the original water-pump assembly and its part numbers with the references listed on this page. Do not rely on horsepower alone.
What are the signs of a failing water-pump impeller?
Possible signs include a weak or absent tell-tale stream, an overheating warning or alarm, elevated operating temperature, or visible cracking, brittleness, or missing vanes during inspection.
How often should the impeller be replaced?
Replacement intervals vary with engine use, storage conditions, and the manufacturer's service schedule. Inspect and replace the impeller according to the specific engine service manual or whenever wear, deformation, cracking, or damage is found.
Does this kit include the housing and mounting hardware?
Yes. The listed package contents include the pump housing, impeller, cartridge insert, cartridge outer plate, water seal damper, woodruff key, and four bolts.
Why does the title cover 6–30 HP while the tables are more specific?
The stated horsepower range covers several different Yamaha applications, but fitment is limited to particular models and configurations. A 6 HP, 15 HP, or 30 HP engine is not automatically compatible. Confirm the exact engine details before ordering.
Is this an original Yamaha part?
No. This is an aftermarket replacement kit. Yamaha and other brand names and part numbers are used only to identify referenced applications and compatibility.
How should I compare the replacement with my original parts?
Compare the housing shape, impeller, plates, key, bolt pattern, and all listed part-number references. If any critical component differs, do not install the kit until compatibility has been confirmed.
Safety & Important Information
- Verify the engine model, year, stroke type, and serial-number range before purchase.
- Compare the product and package contents with the original water-pump assembly.
- Do not run an outboard without an adequate water supply or an approved flushing attachment.
- Follow the engine manufacturer's service procedures and torque specifications.
- This is an aftermarket replacement kit, not an original-equipment Yamaha component.
- Professional installation is recommended when the lower unit or cooling system requires service.
About Sea Sierra
- Marine Replacement Parts — We supply aftermarket parts for selected marine repair applications.
- Application-Focused Listings — Use the model and part-number information to verify compatibility before ordering.
- Service Support — Consult the applicable engine service documentation for installation and maintenance procedures.
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