Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP (Replaces 682-W0078-A1-00, 46-84277M)
Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP (Replaces 682-W0078-A1-00, 46-84277M) 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 (Replaces 682-W0078...
Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP (Replaces 682-W0078-A1-00, 46-84277M) 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 (Replaces 682-W0078-A1-00) provides all essential components for servicing your outboard's water pump. It is designed for a precise fit on Yamaha 2-stroke 9.9/15 HP (1984–1995) and 4-stroke 9.9 HP (1985–2004) engines, as well as select Mariner 9.9C and 15C outboards.
This kit serves as a direct replacement for Yamaha part numbers 682-W0078-00-00 through 682-W0078-A3-00, Sierra 18-3148, GLM 12278/12281, and Mercury/Mariner 46-84277M/T and 46-84118M.
- Engineered as a direct OEM-equivalent replacement for straightforward installation.
- Features a durable, marine-grade rubber impeller for reliable performance in salt and freshwater.
- Includes all necessary gaskets, bolts, and hardware for a complete overhaul.
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 | 46-84277M |
| Mercury/Mariner | 46-84277T |
| Mercury/Mariner | 46-84118M |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha owners, this kit fits a range of 2-stroke and 4-stroke models from the mid-1980s through the mid-2000s. Please check your specific model code and year range.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 9.9D | 9.9 HP | 2-Stroke | 1984–1995 | 682-W0078-A1 | E9.9D engines |
| Yamaha | 15D | 15 HP | 2-Stroke | 1984–1995 | 682-W0078-A1 | E15D engines |
| Yamaha | F9.9A/AE/AM | 9.9 HP | 4-Stroke | 1985–1996 | 682-W0078-A1 | 66N>66N8 models |
| Yamaha | F9.9B/BE/BM | 9.9 HP | 4-Stroke | 1985–1996 | 682-W0078-A1 | 6AU1>6AU6, 6DR1>6DR3 models |
| Yamaha | F9.9 | 9.9 HP | 4-Stroke | 1985–2004 | 682-W0078-A1 | 66R>66R8 models |
| Yamaha | FT9.9 | 9.9 HP | 4-Stroke | 1985–1999 | 682-W0078-A1 | High thrust models |
| Yamaha | F8AM/B/BE/BM | 8 HP | 4-Stroke | 1986–1995 | 682-W0078-A1 | 6G8 models |
| Yamaha | T9.9 | 9.9 HP | 4-Stroke | 1991–1996 | 682-W0078-A1 | 69V2>69V8 models |
For Mariner owners, this kit is compatible with 9.9C and 15C 2-stroke outboards that use the specified codes.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mariner | 9.9C | 9.9 HP | 2-Stroke | All Years | 46-84277M/46-84118M | Code 682 |
| Mariner | 15C | 15 HP | 2-Stroke | All Years | 46-84277M/46-84118M | Code 684 |
Technical Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Direct OEM replacement
- Material
- High-quality rubber (marine grade)
- Connection
- Direct drive via woodruff key
- Operating Temperature
- Salt and freshwater compatible
- Warranty
- Manufacturer warranty against defects
- Production Standards
- ISO9002 certified factory
What’s in the Box
- 1 x Impeller (682-44352-03-00)
- 1 x Cartridge Insert (682-44322-00-00)
- 1 x Outer Plate, Cartridge (682-44323-00-00)
- 2 x Water Pump Gaskets (682-44315-A0-00)
- 1 x Water Seal Damper (682-44365-00-00)
- 1 x Woodruff Key (90280-03024-00)
- 4 x Bolts (97080-06045-00)
Installation Notes
- Disconnect the spark plug leads and shift the outboard into neutral.
- Remove the lower unit (gearcase) by unfastening the mounting bolts located above the anti-cavitation plate.
- Unbolt and carefully lift the water pump housing off the driveshaft. Note the orientation of the old impeller vanes.
- Remove the old impeller, woodruff key, wear plate, and gaskets.
- Thoroughly clean the mating surfaces of the housing and plate, removing any old gasket material or sealant.
- Install the new lower gasket, wear plate, and woodruff key.
- Slide the new impeller onto the driveshaft while turning the shaft clockwise to bed the vanes correctly.
- Install the cartridge insert into the housing and place the upper gasket on the wear plate.
- Apply a thin layer of marine grease or soap-and-water solution to the inside of the pump housing.
- Reinstall the housing and tighten the bolts in a crisscross pattern to the manufacturer's recommended torque.
- Reattach the lower unit to the outboard, ensuring the driveshaft and water tube align correctly.
- Reconnect spark plug leads and test the engine using a flush-pro or in the water, confirming a steady stream from the tell-tale port.
Troubleshooting & FAQ
How do I confirm this kit fits my specific engine model?
Verify your engine's model name, serial number, and year. Cross-reference this information with the compatibility tables provided on this page. For Yamaha, model codes like 682, 66N, or 6G8 are critical identifiers. If you're unsure, check your owner's manual or contact us with your engine details before ordering.
What are the common signs of a failing water pump impeller?
A weak or intermittent water stream from the "tell-tale" outlet is the most common sign. Other indicators include the engine overheating alarm sounding, steam from the exhaust, or reduced engine performance. It's crucial to shut down the engine immediately if overheating is suspected to prevent serious damage.
How often should I replace my outboard's impeller?
As a general maintenance rule, it is recommended to replace the water pump impeller every 1-2 years or every 100-200 hours of use, whichever comes first. For engines operated in saltwater or sandy/silty conditions, annual replacement is strongly advised.
Does this kit include the water pump housing?
No, this is an impeller repair kit that includes the impeller, gaskets, plates, and related hardware. The metal housing is not included. This kit is intended for situations where the housing is still in good condition and does not need replacement.
What is the difference between the Yamaha A1, A2, and A3 part numbers?
The -A1, -A2, and -A3 suffixes typically denote minor revisions or supersessions by the manufacturer over time. These kits are functionally identical and fully interchangeable for all listed compatible models. Our kit is cross-compatible with all of them.
Is this an OEM part or an aftermarket one?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. The kit is manufactured in an ISO 9002 certified facility and is batch-inspected for quality and consistency.
What are the shipping speed and cost?
We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free for most orders, with expedited options available at checkout where applicable.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter any issues, 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 before installation. If anything differs—even if your model appears compatible—do not purchase or install.
- This is an aftermarket replacement part, not an original equipment manufacturer (OEM) component.
- Professional installation is highly recommended for safety, proper function, and to prevent engine damage.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world reliability and longevity.
- Fast Global Fulfillment — With efficient logistics, we offer free standard delivery to most regions, typically arriving in 5–15 days.
- Manufacturer-Direct Value — By working directly with factories, we provide fair pricing without compromising on materials or quality control.
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