Water Pump Impeller Repair Kit – Fits Yamaha F50A 4-Stroke 50HP (Replaces 6BG-W0078-01)
Water Pump Impeller Repair Kit – Fits Yamaha F50A 4-Stroke 50HP (Replaces 6BG-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 F50A 4-Stroke 50HP (Re...
Water Pump Impeller Repair Kit – Fits Yamaha F50A 4-Stroke 50HP (Replaces 6BG-W0078-01) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Water Pump Impeller Repair Kit – Fits Yamaha F50A 4-Stroke 50HP (Replaces 6BG-W0078-01) provides the essential components to restore your outboard’s cooling system. It is designed specifically for Yamaha F50A 4-Stroke 50HP models from 1991–2007 and also fits select E40X, 40X (2-Stroke), and F30A/F40B 4-Stroke models.
It serves as a direct replacement for Yamaha part numbers 6BG-W0078-00-00 and 6BG-W0078-01-00, as well as aftermarket equivalent HJ YHJB-6BG, ensuring a precise fit and reliable performance.
- Installs as a direct OEM-equivalent replacement.
- Manufactured in an ISO9002 certified facility to meet OEM specifications.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6BG-W0078-00-00 |
| Yamaha | 6BG-W0078-01-00 |
| Aftermarket | HJ YHJB-6BG |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha engines, please verify your model and year range to ensure correct fitment. This kit is primarily for the F50A series but may fit other models listed.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F50A | 50 | 4-Stroke | 1991–2007 | 6BG-W0078-01-00 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Direct OEM replacement
- Other Technical Attributes
- Manufactured to OEM specifications in an ISO9002 certified factory
What’s in the Box
The standard repair kit includes:
- 1 x Impeller (6H4-44352-02)
- 1 x Water Pump Repair Kit (6BG-W0078-00-00)
When purchased as part of the complete Yamaha Maintenance Kit for F50A (1991–2007), the following additional items are also included:
- 2 x Drain Gaskets (90430-08020)
- 4 x Anodes (PAF4-04070003)
- 4 x Spark Plugs (NGKDPR6EB-9)
- 1 x Anode (62Y-11325-00A)
- 1 x Anode (67C-45251-00A)
- 1 x Anode (67C-45371-00A)
- 1 x Anode (688-45251-01A)
- 1 x Anode (6E0-45251-11A)
- 1 x Cotter Pin (91490-30025)
- 1 x Fuel Filter VST (6BG-13915-00)
- 1 x Fuel Filter (6C5-24251-00)
- 1 x Fuel Filter (6D8-WS24A-00)
- 1 x Gasket (PAF15-07010022)
- 1 x Oil Filter (5GH-13440-60)
- 1 x O-Ring (PAGB/T3452.1-32.5X1.8)
- 1 x Thermostat (PAF15-07000031)
- 1 x Washer (PAF15-04000003)
Installation Notes
- Disconnect the battery and remove the engine cover for safety.
- Unbolt and carefully lower the lower unit from the engine's midsection.
- With the lower unit on a workbench, remove the water pump housing bolts and lift the housing.
- Remove the old impeller, wear plate, gaskets, and seals. Note their orientation.
- Thoroughly clean all mating surfaces, removing any old gasket material or corrosion.
- Install the new components from the kit in the reverse order of removal.
- Seat the new impeller key correctly and rotate the driveshaft to align the impeller vanes.
- Reassemble the housing and torque bolts to the manufacturer-specified values.
- Reinstall the lower unit, reconnect controls, and secure it.
- Test the engine in water to confirm a steady stream from the tell-tale, indicating proper function.
Troubleshooting & FAQ
How do I know if this kit fits my specific engine model?
This kit is designed for the Yamaha models listed in the compatibility table. Please cross-reference your engine's model, horsepower, and year range with the table. For confirmation, check the OEM part number stamped on your existing components against the numbers in the Part Number Matrix.
What are common signs of a failing water pump impeller?
Key symptoms include the engine overheating at idle or low speeds, a weak or inconsistent water stream from the tell-tale (water outlet), or a brittle or cracked appearance on the existing impeller vanes upon inspection.
How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).
What is the difference between an OEM and an aftermarket kit?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. The parts are manufactured in an ISO 9002 certified facility and batch-inspected for consistency and quality, offering a reliable alternative at a better value.
What are your shipping speeds and costs?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free for most orders, with expedited options available at checkout where applicable.
What is your warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against 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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