Water Pump Impeller – Fits Yamaha 20HP-50HP Outboards (Replaces 6H4-44352-00, 6H4-44352-01, 6H4-44352-02)
Water Pump Impeller – Fits Yamaha 20HP-50HP Outboards (Replaces 6H4-44352-00, 6H4-44352-01, 6H4-44352-02) 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 Impeller – Fits Yamaha 20HP-50HP Outboards (Replaces 6H4...
Water Pump Impeller – Fits Yamaha 20HP-50HP Outboards (Replaces 6H4-44352-00, 6H4-44352-01, 6H4-44352-02) is backordered and will ship as soon as it is back in stock.
Product Details
This replacement Water Pump Impeller fits Yamaha 20HP-50HP Outboards, including a wide range of 2-stroke and 4-stroke models from 1984 to 2005. It is designed for compatibility with C, CV, F, P, and T series engines, ensuring reliable cooling performance.
It serves as a direct replacement for Yamaha part numbers 6H4-44352-00, 6H4-44352-01, and 6H4-44352-02, as well as Sierra part 18-3068.
- Engineered for direct OEM-equivalent installation.
- Constructed from durable rubber/elastomer for longevity.
- Requires woodruff key 90280-03024 for proper installation (sold separately).
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 6H4-44352-00 | Superseded by 6H4-44352-01 & 6H4-44352-02 |
| Yamaha | 6H4-44352-01 | Superseded by 6H4-44352-02 |
| Yamaha | 6H4-44352-02 | Current OEM Part No. |
| Sierra | 18-3068 | Aftermarket equivalent |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
This impeller is designed for a variety of Yamaha outboards. Please check your specific model and year against the list.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | 25 | 25 | 2-Stroke | 1984–1985 | 6H4-44352-02 |
| Yamaha | 30 | 30 | 2-Stroke | 1984–1985 | 6H4-44352-02 |
| Yamaha | 40 | 40 | 2-Stroke | 1984–1994 | 6H4-44352-02 |
| Yamaha | 50 | 50 | 2-Stroke | 1986–1994 | 6H4-44352-02 |
| Yamaha | PRO 50 | 50 | 2-Stroke | 1991–1994 | 6H4-44352-02 |
| Yamaha | 25 | 25 | 2-Stroke | 1999, 2001–2002 | 6H4-44352-02 |
| Yamaha | 30 | 30 | 2-Stroke | 1997–1999, 2001–2002 | 6H4-44352-02 |
| Yamaha | T-25 | 25 | 4-Stroke | 2001–2005 | 6H4-44352-02 |
| Yamaha | F-30 | 30 | 4-Stroke | 2001–2005 | 6H4-44352-02 |
| Yamaha | F-40 | 40 | 4-Stroke | 2000 and up | 6H4-44352-02 |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct OEM Replacement
- Housing Material
- Rubber/Elastomer
- Required Hardware
- Requires woodruff key 90280-03024 for installation
- Warranty
- 1 Year
What’s in the Box
- 1 x Impeller (replaces 6H4-44352-02)
Installation Notes
- Disconnect the battery and shift the outboard into neutral.
- Drain the gearcase oil before removing the lower unit (recommended).
- Unbolt and carefully lower the gearcase/lower unit from the engine.
- Remove the bolts securing the water pump housing cover.
- Lift the housing and take note of the old impeller’s vane direction.
- Remove the old impeller, sliding it off the driveshaft. Remove the old woodruff key.
- Install the new woodruff key (part no. 90280-03024, not included) into the keyway on the driveshaft.
- Slide the new impeller onto the shaft, aligning its keyway with the woodruff key.
- Lubricate the inside of the pump housing and reinstall it while turning the driveshaft clockwise to bend the vanes correctly.
- Secure the housing, re-mount the lower unit, refill the gear oil, and reconnect the battery.
- Start the engine and verify a strong, consistent water stream from the "tell-tale" outlet.
Troubleshooting & FAQ
How do I find the right impeller for my motor?
The best way is to match your engine's model number and year to our compatibility chart. You can also cross-reference your existing impeller's part number with our Part Number Matrix. When in doubt, visually compare your old part to our product photos.
What are signs of a bad water pump impeller?
Common symptoms include the engine overheating at idle or low speeds, a weak or intermittent water stream from the tell-tale indicator, or a melted water pump housing. Failure to replace a worn impeller can lead to severe engine damage.
How often should I replace my impeller?
As a crucial part of preventative maintenance, we recommend replacing the impeller every 100 operating hours or annually, whichever comes first. This is especially important if you operate in saltwater or sandy/silty conditions.
Does this impeller include the required woodruff key?
No, this product is the impeller only. It requires Yamaha woodruff key 90280-03024 for installation, which must be purchased separately.
Is there a performance difference between this and an OEM part?
Our impellers are manufactured to meet or exceed OEM specifications for fit, form, and function. They are made from high-quality elastomer compounds designed for durability and consistent cooling performance, offering a reliable alternative to factory parts.
Why is the tell-tale stream weak after installing a new impeller?
This could be due to several reasons: incorrect installation (vanes bent backward), a blockage in the cooling passages or tell-tale outlet, a worn pump housing, or a missing woodruff key preventing the impeller from spinning with the driveshaft. Double-check your installation and clear any potential debris.
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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