Water Pump Impeller – Fits Mercury Mariner 20-30 HP & Yamaha 25-30 HP (Replaces 47-84797M, 689-44352-02)
This water pump impeller is designed for select Mercury/Mariner 20-30 HP 2-Stroke (1984–1997) and Yamaha 25-30 HP 2-Stroke (1984–1997) outboard engines. It serves as a direct replacement part, ensuring proper fit and function for consistent cooling system performance.
This component directly replaces the following OEM and aftermarket part numbers: Mercury/Mariner 47-84797M / 47-97793M, Yamaha 689-44352-02 / 689-44352-03 / 689-44352-00-00, Sierra 18-3067, CEF 500326, and Mallory 9-45600.
- Engine Compatibility: Fits specific Mercury/Mariner and Yamaha 2-stroke outboards.
- Installation Method: Direct replacement for original stock impellers.
- Materials: Features a durable plastic hub and a flexible neoprene rubber impeller.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
Brand |
Part Number |
Mercury/Mariner |
47-84797M |
Mercury/Mariner |
47-97793M |
Yamaha |
689-44352-02 |
Yamaha |
689-44352-03 |
Yamaha |
689-44352-00-00 |
Sierra |
18-3067 |
CEF |
500326 |
Mallory |
9-45600 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
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.
Mercury/Mariner
Brand |
Model |
Rated HP |
Stroke |
OEM Part No. |
Mercury/Mariner |
20C (Mode Code 6A9) |
20 |
2-Stroke |
47-84797M |
Mercury/Mariner |
25C (through propeller exhaust) |
25 |
2-Stroke |
47-84797M |
Mercury/Mariner |
25D |
25 |
2-Stroke |
47-84797M |
Mercury/Mariner |
28 HP (Mode Code 664) |
28 |
2-Stroke |
47-84797M |
Mercury/Mariner |
30A W30 (W-MARATHON) |
30 |
2-Stroke |
47-84797M |
Yamaha
Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Yamaha |
25 HP |
25 |
2-Stroke |
1984–1987 |
689-44352-02 |
Yamaha |
30 HP |
30 |
2-Stroke |
1984–1987 |
689-44352-02 |
Yamaha |
CV25 |
25 |
2-Stroke |
1989–1990 |
689-44352-02 |
Yamaha |
CV30 |
30 |
2-Stroke |
1989–1990 |
689-44352-02 |
Yamaha |
C25 |
25 |
2-Stroke |
1991–1997 |
689-44352-02 |
Yamaha |
C30 |
30 |
2-Stroke |
1991–1997 |
689-44352-02 |
Technical Specifications
Specification |
Value |
Product Type |
Water Pump Impeller |
Installation |
Direct replacement |
Housing Material |
Plastic hub with neoprene blades |
Dimensions |
Outer Diameter: 68.52 mm (2.7 in) Height: 13.02 mm (0.51 in) Internal Shaft Insert Diameter: 16.03 mm (0.63 in) |
Weight |
19 g (0.67 oz) |
Blade Count |
6 |
Package Contents
Installation Guide
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Safety First: Before starting, disconnect the engine's battery and spark plug leads.
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Access the Lower Unit: Position the engine securely and drain the gearcase oil. Unbolt and carefully remove the lower unit (gearcase) from the upper engine housing.
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Remove the Water Pump Housing: Locate the water pump assembly on top of the lower unit. Unscrew the bolts securing the housing cover to access the impeller.
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Replace the Impeller: Note the orientation of the old impeller blades. Remove the old impeller and key drive. Slide the new impeller onto the driveshaft, ensuring the key is properly aligned. Bend the blades in the correct rotational direction (typically clockwise) as you re-install the housing.
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Reassemble: Clean all mating surfaces, install new gaskets if applicable, and secure the pump housing. Re-attach the lower unit to the engine, refill the gearcase oil, and reconnect the battery and spark plugs.
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Test: Start the engine in water and verify that a steady stream of water is exiting the tell-tale port.
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my exact engine?
A: The most reliable method is to match your engine's original part number to our cross-reference list. Additionally, check your engine's model, HP, and year against our compatible models tables. When in doubt, consulting an exploded parts diagram for your engine can also help verify the correct part.
Q: What are the common signs of a worn or failed water pump impeller?
A: The most common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and in severe cases, an engine alarm for high temperature.
Q: How often should I replace my impeller?
A: For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of use, depending on operating conditions (e.g., saltwater vs. freshwater, sandy/silty environments).
Q: OEM vs. Aftermarket?
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.