Water Pump Impeller Kit – Fits Yamaha 150-300 HP Outboards (Replaces 61A-W0078-A4-00, 61A-W0078-A2-00, 61A-W0078-A3-00)
Water Pump Impeller Kit – Fits Yamaha 150-300 HP Outboards (Replaces 61A-W0078-A4-00, 61A-W0078-A2-00, 61A-W0078-A3-00) 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 Kit – Fits Yamaha 150-300 HP Outboards (Replaces 61A-W0078-A4-00, 61A-W0078-A2-00, 61A-W0078-A3-00) is backordered and will ship as soon as it is back in stock.
Product Details
This comprehensive Water Pump Impeller Kit provides all necessary components for a complete service of the water pump on Yamaha 2-Stroke & 4-Stroke V6 150–300 HP outboard engines (1997–2014). It is designed for F150, F175, F200, F225, F250, and F300 models.
The kit serves as a direct replacement for Yamaha OEM parts 61A-W0078-A4-00, 61A-W0078-A3-00, and 61A-W0078-A2-00. It also interchanges with aftermarket equivalents including Sierra 18-3396-1 and Mallory 9-48618.
- Installation Location: Mounts in the Lower Unit/Gearcase.
- Durable Construction: Features a housing made from high-strength Nylon PA66 plastic.
- Complete Assembly: Includes the impeller, housing, wear plate, gaskets, Woodruff key, and all required hardware.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 61A-W0078-A4-00 | Current OEM part; supersedes earlier versions |
| Yamaha | 61A-W0078-A3-00 | Superseded by 61A-W0078-A4-00 |
| Yamaha | 61A-W0078-A2-00 | Superseded by 61A-W0078-A3-00 |
| Sierra | 18-3396-1 | Aftermarket cross-reference |
| Mallory | 9-48618 | Aftermarket cross-reference |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure correct fitment.
This kit is designed for the following V6 Yamaha outboard models. Please verify your specific model and year range.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F150 | 150 | 4-Stroke | 1997–2014 | 61A-W0078-A4-00 | Supersedes 61A-W0078-A3-00 |
| Yamaha | F175 | 175 | 4-Stroke | 1997–2014 | 61A-W0078-A4-00 | Supersedes 61A-W0078-A3-00 |
| Yamaha | F200 | 200 | 4-Stroke | 1997–2014 | 61A-W0078-A4-00 | Supersedes 61A-W0078-A3-00 |
| Yamaha | F225 | 225 | 4-Stroke | 1997–2014 | 61A-W0078-A4-00 | Supersedes 61A-W0078-A3-00 |
| Yamaha | F250 | 250 | 4-Stroke | 1997–2005 | 61A-W0078-A4-00 | Supersedes 61A-W0078-A3-00 |
| Yamaha | F300 | 300 | 4-Stroke | 2004–2005 | 61A-W0078-A4-00 | Supersedes 61A-W0078-A3-00 |
| Yamaha | 150-300 HP | 150-300 | 2-Stroke | 1997–2005 | 61A-W0078-A4-00 | V6 models, supersedes 61A-W0078-A3-00 |
Technical Specs
- Product Type
- Water Pump Impeller Kit with Housing
- Installation
- Lower Unit/Gearcase
- Connection
- Direct Fit
- Housing Material
- Nylon PA66 Plastic
- Housing Color
- Black
- Fitting Type
- Direct Replacement
- Warranty
- 1 Year (Aftermarket)
- Other Technical Attributes
- Kit includes impeller, housing, insert cup, wear plate, gaskets, key, pins, and hardware
What’s in the Box
- 1 x Cartridge Insert (61A-44322-02-00)
- 1 x Water Pump Gasket (6E5-44315-A0-00)
- 1 x Impeller (6E5-44352-01-00)
- 1 x Cartridge Outer Plate (6G5-44323-01-00)
- 4 x Bolt with Washer (90119-08M14-00)
- 1 x Woodruff Key (90280-04M05-00)
- 1 x O-Ring (93210-37M67-00)
- 1 x O-Ring (93210-86M38-00)
- 2 x Dowel Pin (93606-12019-00)
Installation Notes
- Disconnect the battery and remove the propeller for safety.
- Place a drain pan under the lower unit and remove the drain screw to empty the gearcase oil.
- Unbolt and carefully lower the gearcase from the outboard's upper housing.
- Remove the bolts securing the water pump housing to access the old impeller and components.
- Note the orientation of all parts before removal. Clean all mating surfaces of old gasket material and debris.
- Install the new wear plate, gaskets, and insert cup from the kit.
- Slide the new impeller onto the driveshaft with the Woodruff key properly seated.
- Install the new housing, apply a light waterproof grease to the interior, and torque bolts to manufacturer specifications.
- Re-install the lower unit, ensuring the driveshaft, shift shaft, and water tube are correctly aligned.
- Refill the gearcase with fresh marine gear lube to the proper level.
- Reconnect the battery, start the engine on a water supply (flushing muffs), and confirm a steady stream of water from the tell-tale port.
Troubleshooting & FAQ
How do I confirm this kit fits my engine?
The best way is to check the Part Number Matrix and Engine & Model Compatibility tables on this page. Compare the OEM part numbers listed to your engine's service manual. Visually comparing the old pump to our product photos can also help confirm fitment.
What are the signs of a failing water pump?
Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, or an audible alarm from the engine's warning system. Steam from the engine cowling is also a critical indicator.
How often should a water pump impeller be replaced?
As a preventative maintenance item, most manufacturers recommend replacing the impeller every 1-2 years or every 100-200 hours of operation, whichever comes first. Refer to your owner's manual for specific service intervals.
Is this a complete kit with the housing?
Yes, this is a complete water pump repair kit that includes the impeller, housing, gaskets, wear plate, and all necessary hardware shown in the "What's in the Box" section. No other components are typically needed for a standard replacement.
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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