Water Pump Impeller Repair Kit – Fits Yamaha 4-Stroke F25B-F50A, E40X (Replaces 6BG-W0078-01-00, 6BG-W0078-00-00)
Water Pump Impeller Repair Kit – Fits Yamaha 4-Stroke F25B-F50A, E40X (Replaces 6BG-W0078-01-00, 6BG-W0078-00-00) 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 Impeller Repair Kit – Fits Yamaha 4-Stroke F25B-F50A, E4...
Water Pump Impeller Repair Kit – Fits Yamaha 4-Stroke F25B-F50A, E40X (Replaces 6BG-W0078-01-00, 6BG-W0078-00-00) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Repair Kit – Fits Yamaha F50A 4-Stroke (1991-2007) is designed for a range of Yamaha outboard engines, including 4-stroke models F25B, F30A, F40B, and F50A, as well as 2-stroke models E40X and 40X. It provides all the necessary components for a complete water pump service to restore cooling system performance.
It serves as a direct replacement for Yamaha OEM part numbers 6BG-W0078-00-00 and 6BG-W0078-01-00 and interchanges with Sierra 18-3450, GLM 12510, and JLM YHJB-6BG.
- Engineered for direct OEM-level fit and function.
- Kit includes the essential 6H4-44352-02 impeller and all required gaskets, seals, and hardware.
- Restores cooling efficiency to prevent engine overheating.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Yamaha | 6BG-W0078-00-00 |
| Yamaha | 6BG-W0078-01-00 |
| Sierra | 18-3450 |
| GLM | 12510 |
| JLM | YHJB-6BG |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | F25B | 25 | 4-Stroke | 6BG-W0078-01-00 | |
| Yamaha | F30A | 30 | 4-Stroke | 6BG-W0078-01-00 | |
| Yamaha | F30LA | 30 | 4-Stroke | 6BG-W0078-01-00 | |
| Yamaha | F40B | 40 | 4-Stroke | 6BG-W0078-01-00 | |
| Yamaha | F40LA | 40 | 4-Stroke | 6BG-W0078-01-00 | |
| Yamaha | F50A | 50 | 4-Stroke | 1991–2007 | 6BG-W0078-01-00 |
| Yamaha | E40X | 40 | 2-Stroke | 6BG-W0078-01-00 | |
| Yamaha | 40X | 40 | 2-Stroke | 6BG-W0078-01-00 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Direct OEM replacement
- Other Technical Attributes
- Includes impeller 6H4-44352-02
What’s in the Box
- 1 x Cover, Water Pump (63D-44312-00-00)
- 1 x Gasket, Water Pump (63D-44316-00-00)
- 1 x Insert, Cartridge (63D-44322-00-00)
- 1 x Outer Plate, Cartridge (63D-44323-00-00)
- 1 x Water Seal 2 (663-44366-00-00)
- 1 x Impeller (6H4-44352-02-00)
- 4 x Bolt, W/ Washer (90119-08M15-00)
- 1 x Key, Woodruff (90280-03M03-00)
- 1 x O-Ring (93210-59MG7-00)
Installation Notes
- Disconnect the battery and shift the outboard into neutral.
- Remove the lower unit (gearcase) by unbolting it from the engine's midsection. Be prepared for it to be heavy.
- Place the lower unit on a workbench. Unbolt and remove the water pump housing.
- Take note of the old components' orientation. Remove the old impeller, gaskets, seals, and wear plates.
- Clean all mating surfaces thoroughly, ensuring they are free of old gasket material and corrosion.
- Install the new components from the kit in the reverse order of removal. Lightly grease the new impeller and insert it while turning the driveshaft clockwise.
- Reinstall the water pump housing, ensuring all seals are seated correctly. Torque bolts to manufacturer specifications.
- Apply a light coat of marine grease to the drive shaft splines and reinstall the lower unit.
- Once assembled, start the engine using a flush attachment and confirm a steady stream of water from the tell-tale port.
Troubleshooting & FAQ
How do I know if my water pump impeller is failing?
Common signs include a weak or intermittent water stream from the engine's tell-tale port, an engine overheating alarm, or visible damage (cracked, brittle, or missing vanes) on the old impeller upon inspection.
How often should I replace my water pump impeller?
As a general maintenance guideline, it is recommended to inspect your impeller annually and replace it every 1-2 years or every 100-200 hours of operation, whichever comes first. This interval may be shorter if you operate in sandy, silty, or saltwater conditions.
The compatibility table lists my engine model but has no year range. Will this kit fit?
If your specific engine model (e.g., F40B) is listed, this kit is designed to be compatible. The year range for F50A is confirmed, while other models use this same kit across their production years. Always verify by matching the OEM part number (6BG-W0078-01-00) to your service manual if uncertain.
Is this kit difficult to install?
Installation is straightforward for those with mechanical experience but requires removing the lower unit. If you are not comfortable performing this service, we recommend professional installation to ensure safety and proper function.
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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