Water Pump Impeller with Key – Fits Yamaha 4 HP & 6 HP 2-Stroke/4-Stroke Outboards
This aftermarket water pump impeller with key is designed to fit Yamaha 4 HP and 6 HP outboard motors, covering both 2-stroke and 4-stroke models from 1984 and up. It ensures reliable cooling system performance for your Yamaha F4, F6, and legacy 4 HP/5 HP engines.
This impeller directly replaces OEM part numbers 6E0-44352-00, 6E0-44352-01, and 6E0-44352-03, as well as aftermarket equivalents from CEF Marine, Sierra Marine, and Mallory Marine.
- Includes impeller with drive key/pin for complete installation
- 6-blade design with precise OEM-spec dimensions
- Compatible with both 2-stroke and 4-stroke Yamaha small outboards
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Yamaha |
6E0-44352-00 |
| Yamaha |
6E0-44352-01 |
| Yamaha |
6E0-44352-03 |
| CEF Marine |
500325 |
| Sierra Marine |
18-3073 |
| Mallory Marine |
9-45611 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Yamaha owners, here's a guide to help you identify your engine's serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.
| Brand |
Model |
Rated HP |
Stroke |
Years |
| Yamaha |
F4 |
4 hp |
4-Stroke |
1984 & UP |
| Yamaha |
F6 |
6 hp |
4-Stroke |
2006 & UP |
| Yamaha |
4 hp |
4 hp |
2-Stroke |
1984 - 1999 |
| Yamaha |
5 hp |
5 hp |
2-Stroke |
1984 - 2002 |
Technical Specifications
| Specification |
Value |
| Number of Blades |
6 |
| Impeller Height |
12.6 mm / 0.50 inch |
| Overall Diameter |
40.0 mm / 1.57 inch |
| Hub Shaft Diameter |
11.0 mm / 0.43 inch |
| Net Weight |
0.35 oz |
Package Contents
- Water Pump Impeller with Key/Pin
Installation Guide
- Disconnect the fuel line and remove the engine cover to access the lower unit.
- Remove the propeller and drain gear oil from the lower unit.
- Unbolt and carefully separate the lower unit from the midsection.
- Remove the water pump housing bolts and lift off the housing to expose the old impeller.
- Carefully remove the old impeller and drive key from the driveshaft. Inspect the housing and plate for wear or scoring.
- Lubricate the new impeller blades with glycerin or soapy water (never petroleum-based grease).
- Insert the drive key into the driveshaft slot, ensuring it is fully seated.
- Slide the new impeller onto the driveshaft with blades oriented in the correct rotation direction (usually clockwise when viewed from above).
- Reinstall the water pump plate and housing, ensuring all gaskets are properly aligned and O-rings are in place.
- Reattach the lower unit to the midsection, tightening bolts to the manufacturer's torque specifications.
- Refill the lower unit with the appropriate gear oil, reinstall the propeller, and reattach the engine cover.
- Run the engine in a test tank or on-water and confirm a steady stream of water from the telltale (pilot hole).
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my Yamaha engine?
A: Cross-reference your engine model and year in the Compatible Engine Models table above. You can also verify by matching the OEM part number (6E0-44352-00, 6E0-44352-01, or 6E0-44352-03) stamped on your original impeller or listed in your engine's parts diagram.
Q: How often should I replace my water pump impeller?
A: Yamaha recommends replacing the impeller every 2–3 years or 200–300 operating hours, whichever comes first. If you operate in sandy, silty, or debris-heavy water, inspect and replace it annually.
Q: What are the signs that my impeller is failing?
A: Common symptoms include weak or no water flow from the telltale, engine overheating, steam from the engine, or reduced performance. Inspect the impeller immediately if any of these occur.
Q: Does this impeller come with the drive key?
A: Yes, this kit includes both the impeller and the drive key/pin required for installation.
Q: Can I use this impeller on both 2-stroke and 4-stroke Yamaha engines?
A: Yes, this impeller is compatible with both 2-stroke (4 HP 1984–1999, 5 HP 1984–2002) and 4-stroke (F4 1984 & up, F6 2006 & up) models as listed in the compatibility table.
Q: Is this an OEM part or an aftermarket replacement?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.