Water Pump Impeller Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3-W0078-A0-00, 6H3-W0078-02-00)
Water Pump Impeller Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3-W0078-A0-00, 6H3-W0078-02-00) is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
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.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Water Pump Impeller Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3...
Water Pump Impeller Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3-W0078-A0-00, 6H3-W0078-02-00) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Repair Kit – Fits Yamaha 50-70 HP Outboards (Replaces 6H3-W0078-A0-00, 6H3-W0078-02-00) is designed for Yamaha 2-Stroke 60–70 HP (1997–2003) and 4-Stroke 50–60 HP High Thrust (1997–present) outboard motors. It includes all necessary components to rebuild the lower unit water pump for reliable engine cooling.
This kit provides a direct interchange for Yamaha part numbers 6H3-W0078-00-00, 6H3-W0078-01-00, 6H3-W0078-02-00, and 6H3-W0078-A0-00, as well as Sierra equivalents 18-3466, 18-3461, and 18-3428-1.
- Installation Location: Lower Unit
- Complete rebuild kit including impeller, gaskets, and hardware.
- Engineered for consistent performance in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6H3-W0078-A0-00 |
| Yamaha | 6H3-W0078-02-00 |
| Yamaha | 6H3-W0078-01-00 |
| Yamaha | 6H3-W0078-00-00 |
| Sierra | 18-3466 |
| Sierra | 18-3461 |
| Sierra | 18-3428-1 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha 2-Stroke models:
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 60F | 60 | 2-Stroke | 1997–2003 | 6H3-W0078-A0-00 | |
| Yamaha | 60TLR | 60 | 2-Stroke | 2001–2003 | 6H3-W0078-A0-00 | Including 60TLRZ (2001), 60TLRA (2002), 60TLRB (2003) |
| Yamaha | 70B | 70 | 2-Stroke | 1997–2003 | 6H3-W0078-A0-00 | |
| Yamaha | 70TLR | 70 | 2-Stroke | 1997–2003 | 6H3-W0078-A0-00 | Including 70TLRV (1997) through 70TLRB (2003) |
| Yamaha | C60TLR | 60 | 2-Stroke | 1997–2001 | 6H3-W0078-A0-00 | Models C60TLRV through C60TLRZ |
| Yamaha | C70TLR | 70 | 2-Stroke | 2000–2001 | 6H3-W0078-A0-00 | Models C70TLRY and C70TLRZ |
| Yamaha | P60TLH | 60 | 2-Stroke | 1997–1999 | 6H3-W0078-A0-00 | Models P60TLHV through P60TLHX |
For Yamaha 4-Stroke High Thrust models:
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | T50 | 50 | 4-Stroke | 1997–Present | 6H3-W0078-A0-00 | High Thrust models; includes T50TLRV through current |
| Yamaha | FT50 | 50 | 4-Stroke | 1997–Present | 6H3-W0078-A0-00 | High Thrust models; includes FT50B through current |
| Yamaha | F50TLH | 50 | 4-Stroke | 1997 | 6H3-W0078-A0-00 | Model F50TLHV |
| Yamaha | F50TLR | 50 | 4-Stroke | 1997 | 6H3-W0078-A0-00 | Model F50TLRV |
| Yamaha | T60 | 60 | 4-Stroke | 2003–Present | 6H3-W0078-A0-00 | High Thrust models; includes T60TLRB through current |
| Yamaha | FT60 | 60 | 4-Stroke | 2003–Present | 6H3-W0078-A0-00 | High Thrust models; includes FT60B through current |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Lower Unit
- Weight
- ~250 g (8.8 oz)
- Warranty
- Standard Manufacturer Warranty
- Other Technical Attributes
- Complete water pump rebuild kit including impeller, gaskets, and hardware
What’s in the Box
- 1 x Cartridge Insert (663-44322-00-00)
- 1 x Impeller (6H3-44352-01/697-44352-00)
- 1 x Water Pump Gasket (6H3-44315-A0-00)
- 1 x Cartridge Outer Plate/Wear Plate (6H3-44323-00-00)
- 1 x Cartridge Gasket (6H3-44324-A0-00)
- 1 x Water Pump Gasket (688-44316-A0-00)
- 1 x O-Ring (93210-46044-00)
- 2 x Bolts (97095-08045-00)
- 2 x Bolts (97395-08055-00)
- 1 x Woodruff Key (90280-03M03-00)
Installation Notes
- Disconnect the battery and shift the outboard to the neutral position.
- Remove the lower unit (gearcase) by unbolting it from the engine's midsection.
- Position the lower unit securely on a workbench.
- Unbolt and remove the water pump housing to access the old impeller and gaskets.
- Clean all mating surfaces thoroughly, removing any old gasket material or corrosion.
- Install the new cartridge, gaskets, wear plate, and impeller from the kit. Ensure the Woodruff key is correctly seated.
- Lubricate the inside of the housing and the new impeller with a marine-safe lubricant.
- Reinstall the water pump housing, tightening bolts to the manufacturer's specified torque.
- Reattach the lower unit to the outboard, ensuring all connections are properly aligned.
- Once assembled, test the engine using a water source (flusher or in water) to verify correct pump operation.
Troubleshooting & FAQ
How do I know if my water pump is failing?
Common signs of a failing water pump include a weak or non-existent "telltale" water stream, engine overheating alarms, and visible damage to the old impeller (cracked, brittle, or missing vanes) during inspection.
What is the recommended replacement interval?
For optimal reliability, most manufacturers recommend inspecting the impeller annually and replacing the entire water pump kit every 2-3 years or 200-300 operating hours, whichever comes first. Usage in saltwater or silty/sandy conditions may require more frequent service.
Can I install this kit myself?
This kit can be installed by individuals with moderate mechanical skill and the proper tools. However, due to the importance of correct assembly for engine health, professional installation is recommended if you are not fully comfortable with the process.
Is the impeller material the same as the OEM part?
The impeller is made from a durable, high-quality neoprene compound designed for longevity and performance in marine environments, comparable to OEM standards.
Will this kit fit my High Thrust (T50/T60) model?
Yes, this kit is specifically designed to fit Yamaha's High Thrust 4-stroke models from 50 HP to 60 HP, covering years from 1997 to the present. Always confirm your specific model and year in our compatibility chart.
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.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
