Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP Outboard (Replaces 682-W0078-A1-00)
Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP Outboard (Replaces 682-W0078-A1-00) is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP Outboard (Replaces ...
Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP Outboard (Replaces 682-W0078-A1-00) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP Outboard (Replaces 682-W0078-A1-00) is designed for Yamaha 9.9 HP and 15 HP 2-stroke outboard engines from 1984–1995 and select 4-stroke models produced between 1985 and 2004. It also fits compatible Mariner outboards sharing the same engine specifications.
This kit serves as a direct interchange for Yamaha part numbers like 682-W0078-00-00 and 682-W0078-A1-00, as well as aftermarket equivalents from Sierra (18-3148), GLM (12278, 12281), and Mercury/Mariner (84118M).
- Engineered as a direct OEM-style replacement for a precise fit.
- Constructed from marine-grade stainless steel alloy and durable rubber for corrosion resistance.
- Kit includes the essential impeller required for a standard service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Yamaha | 682-W0078-00-00 |
| Yamaha | 682-W0078-01-00 |
| Yamaha | 682-W0078-A1-00 |
| Yamaha | 682-W0078-A2-00 |
| Yamaha | 682-W0078-A3-00 |
| Sierra | 18-3148 |
| GLM | 12278 |
| GLM | 12281 |
| Mercury/Mariner | 84118M |
| Mercury/Mariner | 46-84277T |
| Mercury/Mariner | 46-84277M |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
For Yamaha Owners: This kit fits a range of 2-stroke and 4-stroke models, including high-thrust (FT/T) versions from 1984 to 2004. Check your specific model code.
For Mariner Owners: This kit is compatible with 9.9C and 15C models that use the 682 and 684 engine codes, respectively.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 9.9D, E9.9D | 9.9 | 2-Stroke | 1984–1995 | 682-W0078-A1 | |
| Yamaha | 15D, E15D | 15 | 2-Stroke | 1984–1995 | 682-W0078-A1 | |
| Yamaha | F9.9A, AE, AM | 9.9 | 4-Stroke | 1985–1996 | 682-W0078-A1 | |
| Yamaha | F9.9B, BE, BM | 9.9 | 4-Stroke | 1985–1996 | 682-W0078-A1 | |
| Yamaha | F9.9 | 9.9 | 4-Stroke | 1985–2004 | 682-W0078-A1 | |
| Yamaha | F8AM, B, BE, BM | 8 | 4-Stroke | 1986–1995 | 682-W0078-A1 | |
| Yamaha | FT9.9 | 9.9 | 4-Stroke | 1985–1999 | 682-W0078-A1 | High thrust model |
| Yamaha | T9.9 | 9.9 | 4-Stroke | 1991–1999 | 682-W0078-A1 | |
| Mariner | 9.9C (Code 682) | 9.9 | 2-Stroke | All Years | 84118M | |
| Mariner | 15C (Code 684) | 15 | 2-Stroke | All Years | 84118M |
Technical Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Direct OEM replacement
- Housing Material
- Marine-grade stainless steel alloy and rubber
- Housing Color
- Black/Metal
- Other Technical Attributes
- Manufactured to OEM specifications in ISO9002 certified factory
What’s in the Box
- 1 x Impeller (682-W0078-A1)
Installation Notes
- Disconnect the spark plug wires and shift the engine into neutral.
- Remove the lower unit (gearcase) from the outboard's midsection by unbolting it.
- Locate and unbolt the water pump housing to access the old impeller.
- Clean any debris or old gasket material from the housing and wear plate surfaces.
- Install the new impeller, ensuring the vanes are oriented correctly (typically clockwise).
- Reassemble the water pump housing with new gaskets and seals as needed.
- Reinstall the lower unit, ensuring the water tube and driveshaft are properly aligned.
- Connect spark plug wires and test the engine in water, confirming a steady stream from the tell-tale outlet.
Troubleshooting & FAQ
How do I confirm this kit fits my specific engine model?
Always check your engine's model number and year against the compatibility chart. For Mariner models, confirm the engine code (e.g., 682 for 9.9C) matches the information in the listing, as this is a critical identifier.
What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alerts or alarms, and, in severe cases, steam from the exhaust. Reduced engine performance can also be an indicator.
How often should I replace my outboard's impeller?
As a general maintenance rule, it is recommended to inspect the impeller annually and replace it every 1–2 years or every 100–200 hours of operation, whichever comes first. Usage in saltwater or silty/sandy conditions may require more frequent replacement.
Does this kit include the pump housing?
This particular kit includes the impeller and other components as listed in the "What's in the Box" section. Based on the provided data, it does not include the main pump housing. Always verify the contents against your needs.
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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