Water Pump Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3-W0078-02-00, 18-3415)
Water Pump Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3-W0078-02-00, 18-3415) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Water Pump Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3-W0078-02...
Water Pump Repair Kit – Fits Yamaha 50-70 HP (Replaces 6H3-W0078-02-00, 18-3415) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Water Pump Repair Kit – Fits Yamaha 50-70 HP Outboards (Replaces 6H3-W0078-02-00) is designed for a precise fit on a range of Yamaha engines. It is compatible with 2-stroke models from 60 to 70 HP (1992–2003) and 4-stroke models including the T50 (1997–2010) and T60 (2003–2010) series.
The kit serves as a direct replacement for OEM part numbers Yamaha 6H3-W0078-02-00 and 6H3-W0078-A0-00, as well as aftermarket cross-references Sierra 18-3415 and GLM 12283.
- Engineered for direct-fit installation, simplifying routine maintenance.
- Includes all essential components for a complete water pump overhaul: impeller, gaskets, plates, key, and hardware.
- Restores cooling system performance to prevent engine overheating and ensure reliability.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 6H3-W0078-02-00 | Current OEM Part |
| Yamaha | 6H3-W0078-A0-00 | Superseded Part |
| Sierra | 18-3415 | Aftermarket Interchange |
| GLM | 12283 | Aftermarket Interchange |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is verified for the following Yamaha outboard engines.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | T50LA | 50 | 4-Stroke | 2012 | 6H3-W0078-02-00 | |
| Yamaha | T50LA | 50 | 4-Stroke | 2012 | 6H3-W0078-02-00 | Listed as 0412 variant |
| Yamaha | T50LB | 50 | 4-Stroke | 2013–2017 | 6H3-W0078-02-00 | Includes models 0113-0117 |
| Yamaha | T50TLR | 50 | 4-Stroke | 2005–2010 | 6H3-W0078-02-00 | Includes models 0405-0411 |
| Yamaha | T50TLRA | 50 | 4-Stroke | 2002 | 6H3-W0078-02-00 | |
| Yamaha | T50TLRB | 50 | 4-Stroke | 2003 | 6H3-W0078-02-00 | |
| Yamaha | T50TLRC | 50 | 4-Stroke | 2004 | 6H3-W0078-02-00 | |
| Yamaha | T50TLRD | 50 | 4-Stroke | 2005 | 6H3-W0078-02-00 | |
| Yamaha | T50TLRV-Z | 50 | 4-Stroke | 1997–2001 | 6H3-W0078-02-00 | |
| Yamaha | T60LA | 60 | 4-Stroke | 2012 | 6H3-W0078-02-00 | |
| Yamaha | T60LB | 60 | 4-Stroke | 2013–2017 | 6H3-W0078-02-00 | Includes models 0113-0117 |
| Yamaha | T60TLR | 60 | 4-Stroke | 2005–2010 | 6H3-W0078-02-00 | Includes models 0405-0411 |
| Yamaha | T60TLRB | 60 | 4-Stroke | 2003 | 6H3-W0078-02-00 | |
| Yamaha | T60TLRC | 60 | 4-Stroke | 2004 | 6H3-W0078-02-00 | |
| Yamaha | T60TLRD | 60 | 4-Stroke | 2005 | 6H3-W0078-02-00 | |
| Yamaha | 60TLRB | 60 | 2-Stroke | 2003 | 6H3-W0078-02-00 | |
| Yamaha | 60TLRZ | 60 | 2-Stroke | 2001 | 6H3-W0078-02-00 | |
| Yamaha | 70TLRA | 70 | 2-Stroke | 2002 | 6H3-W0078-02-00 | |
| Yamaha | 70TLRB | 70 | 2-Stroke | 2003 | 6H3-W0078-02-00 | |
| Yamaha | 70TLRV-Z | 70 | 2-Stroke | 1997–2001 | 6H3-W0078-02-00 | Includes TLRV, TLRW, TLRX, TLRY, TLRZ |
| Yamaha | C60TLRV-Z | 60 | 2-Stroke | 1997–2001 | 6H3-W0078-02-00 | Model C60 |
| Yamaha | C70TLRY-Z | 70 | 2-Stroke | 2000–2001 | 6H3-W0078-02-00 | Model C70 |
| Yamaha | F50TLHV | 50 | 4-Stroke | 1997 | 6H3-W0078-02-00 | |
| Yamaha | F50TLRV | 50 | 4-Stroke | 1997 | 6H3-W0078-02-00 | |
| Yamaha | P60TLHV | 60 | 2-Stroke | 1997 | 6H3-W0078-02-00 | |
| Yamaha | P60TLHW | 60 | 2-Stroke | 1998 | 6H3-W0078-02-00 | |
| Yamaha | P60TLHX | 60 | 2-Stroke | 1999 | 6H3-W0078-02-00 | |
| Yamaha | C60 | 60 | 2-Stroke | 1996–2001 | 6H3-W0078-02-00 | |
| Yamaha | E60 | 60 | 2-Stroke | 1995–1996 | 6H3-W0078-02-00 | |
| Yamaha | P60 | 60 | 2-Stroke | 1992–1999 | 6H3-W0078-02-00 | |
| Yamaha | 70 | 70 | 2-Stroke | 1992–2003 | 6H3-W0078-02-00 | |
| Yamaha | C70 | 70 | 2-Stroke | 2000–2001 | 6H3-W0078-02-00 |
Technical Specs
- Product Type
- Water Pump Repair Kit
- Installation
- Direct replacement
What’s in the Box
- 1 x Insert, Cartridge (663-44322-00-00)
- 1 x Impeller (6H3-44352-00-00)
- 1 x Water Pump Gasket (6H3-44315-A0-00)
- 1 x Outer Plate, Cartridge (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, With Washer (90119-08M14-00)
- 2 x Bolts, With Washer (90119-08M33-00)
- 1 x Woodruff Key (90280-03M03-00)
Installation Notes
- Disconnect the negative battery cable and remove the engine cowling.
- Shift the outboard into the neutral position to aid in driveshaft alignment.
- Remove the bolts securing the lower unit (gearcase) to the engine's midsection.
- Carefully separate the lower unit from the upper housing. Have an assistant help support its weight.
- Unbolt the water pump housing and slide it up off the driveshaft.
- Remove the old impeller, wear plate, gaskets, and Woodruff key. Note their orientation for reassembly.
- Thoroughly clean all mating surfaces, removing any old gasket material or corrosion.
- Install the new gaskets, cartridge, and outer plate as supplied in the kit.
- Insert the new Woodruff key and slide the new impeller down the driveshaft, turning it clockwise to align the vanes.
- Reinstall the water pump housing and tighten the bolts to the manufacturer's specified torque.
- Reattach the lower unit to the engine, ensuring the driveshaft, shift shaft, and water tube are properly aligned.
- Once fully reassembled, test the engine with a reliable water source (like "earmuffs") to verify strong water flow from the tell-tale outlet.
Troubleshooting & FAQ
How do I confirm this kit fits my specific Yamaha model?
Your engine's model and year are typically found on a metal plate or sticker on the transom clamp bracket. Cross-reference this information with our compatibility table. If you are uncertain, contact us with your engine's Primary ID (PID) or serial number before ordering.
What are common signs of a failing water pump?
Key indicators include a weak or no water stream from the "tell-tale" port, engine overheating alarms, and visible steam from the engine. A worn or damaged impeller is the most frequent cause and should be inspected regularly.
How often should I replace my water pump impeller?
For best results, we recommend replacing the water pump impeller every one to two years or every 100-200 hours of operation. This interval may be shorter if you operate frequently in saltwater or debris-heavy water.
What is the difference between part numbers 6H3-W0078-02-00 and 6H3-W0078-A0-00?
These are official supersessions from Yamaha. Part number 6H3-W0078-A0-00 is an earlier version that was replaced by 6H3-W0078-02-00. Our kit is a direct replacement for both of these interchangeable parts.
Are any special tools needed for installation?
Standard metric sockets, a torque wrench, and basic hand tools are required. A gasket scraper or plastic putty knife can be helpful for cleaning surfaces. No proprietary dealer tools are necessary for a standard installation.
Why does the kit include two different sets of bolts?
This kit fits a wide range of model years and variations. Different models may require different length bolts for the water pump housing. This kit includes both common sizes to ensure you have the correct hardware for your specific engine.
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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