Water Pump Impeller – Fits Yamaha 25-50 HP (Replaces 6H4-44352-02-00, 6H4-44352-00-00, 6H4-44352-01-00, Sierra 18-3068)
Water Pump Impeller – Fits Yamaha 25-50 HP (Replaces 6H4-44352-02-00, 6H4-44352-00-00, 6H4-44352-01-00, Sierra 18-3068) 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 25-50 HP (Replaces 6H4-44352-02-0...
Water Pump Impeller – Fits Yamaha 25-50 HP (Replaces 6H4-44352-02-00, 6H4-44352-00-00, 6H4-44352-01-00, Sierra 18-3068) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller – Fits Yamaha 25-50 HP Outboards (Replaces 6H4-44352-02-00) is designed for a broad range of Yamaha engines, providing reliable cooling performance. It is compatible with 2-Stroke models from 25 to 50 HP (1984–2002) including C30, P50, and PRO50 models, as well as 4-Stroke models from 25 to 40 HP (1998–2017) including F25, T25, F30, and F40 models.
This part is a direct replacement for Yamaha part numbers 6H4-44352-02-00, 6H4-44352-00-00, 6H4-44352-01-00, and Sierra 18-3068.
- Engineered for direct OEM replacement and fitment.
- Constructed from durable neoprene and hardened nylon for longevity.
- Includes the essential impeller key for a complete installation.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6H4-44352-02-00 |
| Yamaha | 6H4-44352-00-00 |
| Yamaha | 6H4-44352-01-00 |
| Sierra | 18-3068 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This impeller fits the following Yamaha 2-Stroke outboard models:
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 25HP | 25 | 2-Stroke | 1997–2002 | 6H4-44352-02-00 | |
| Yamaha | 30HP C30 | 30 | 2-Stroke | 1987–2002 | 6H4-44352-02-00 | |
| Yamaha | 40HP | 40 | 2-Stroke | 1984–1994 | 6H4-44352-02-00 | |
| Yamaha | 50HP | 50 | 2-Stroke | 1984–1994 | 6H4-44352-02-00 | |
| Yamaha | 50HP P50 | 50 | 2-Stroke | 1991–1994 | 6H4-44352-02-00 | |
| Yamaha | 50HP PRO 50 | 50 | 2-Stroke | 1987–1994 | 6H4-44352-02-00 | |
| Yamaha | 50HP JET 50 | 50 | 2-Stroke | 1986–1995 | 6H4-44352-02-00 |
This impeller fits the following Yamaha 4-Stroke outboard models:
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F25 | 25 | 4-Stroke | 1998–2017 | 6H4-44352-02-00 | |
| Yamaha | T25 | 25 | 4-Stroke | 2001–2013 | 6H4-44352-02-00 | |
| Yamaha | F30 | 30 | 4-Stroke | 2001–2017 | 6H4-44352-02-00 | |
| Yamaha | F40 | 40 | 4-Stroke | 2000–2017 | 6H4-44352-02-00 |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct OEM Replacement
- Material
- Neoprene and Hardened Nylon
- Dimensions
- 5.67 × 4.49 × 0.79 inches (144 × 114 × 20 mm) [package dimensions]
- Weight
- 0.8 oz (22.7 g)
- Other Technical Attributes
- Includes impeller key for installation
What’s in the Box
- 1 x Impeller (6H4-44352-02-00)
- 1 x Key
Installation Notes
- Disconnect the engine's battery and shift the outboard into neutral.
- Remove the mounting bolts securing the lower unit (gearcase) to the upper casing.
- Carefully lower the gearcase away from the engine.
- Locate the water pump housing on top of the gearcase and remove its bolts.
- Lift off the housing and slide the old impeller off the driveshaft.
- Clean the housing interior and inspect the wear plate for scoring or damage.
- Install the new impeller key into the slot on the driveshaft.
- Slide the new impeller onto the shaft, turning it clockwise to help seat the vanes inside the housing.
- Re-install the water pump housing, ensuring gaskets are aligned correctly.
- Re-attach the lower unit to the engine, making sure the driveshaft and water tube align.
- Once secured, test the engine using a water supply (flushing muffs) and check for a strong stream from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if this impeller fits my Yamaha engine?
Check your engine's model and year against the compatibility tables. This part is designed for specific Yamaha 2-stroke (25-50 HP, 1984–2002) and 4-stroke (25-40 HP, 1998–2017) models. You can also confirm fitment by matching your existing part number to one of the cross-references, such as 6H4-44352-02-00.
What are the signs of a failing water pump impeller?
Common signs include the engine overheating at low speeds, a weak or intermittent water stream from the tell-tale outlet, or a complete lack of water flow, which can trigger an overheat alarm.
How often should I replace the impeller?
For preventative maintenance, we recommend inspecting the impeller annually and replacing it every 1-2 years or every 100-200 hours of engine use. Service intervals should be shorter in saltwater or silty/sandy conditions.
What is the small metal piece included in the package?
That is the impeller key (or Woodruff key). It is a critical component that locks the impeller to the driveshaft, ensuring it spins with the shaft to pump water. Do not install the impeller without it.
Is this an OEM or aftermarket part?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. The part is manufactured in an ISO 9002 facility and is batch-inspected for consistency and quality.
What are the shipping speed and cost?
We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most locations, with expedited options available at checkout where applicable.
What is the warranty and return policy?
This part is covered by a 1-year warranty against manufacturing defects under normal use. If any issues arise, 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 purchase. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement component, not an OEM part.
- Professional installation is recommended for safety and optimal 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 quality control.
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