Water Pump Impeller with Key – Fits Mercury/Mariner 2-Stroke 50–60 HP and 4-Stroke 40–60 HP (Replaces 47-19453T, 47-19453, 18-8900)
Water Pump Impeller with Key – Fits Mercury/Mariner 2-Stroke 50–60 HP and 4-Stroke 40–60 HP (Replaces 47-19453T, 47-19453, 18-8900) 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 with Key – Fits Mercury/Mariner 2-Stroke 50–60 ...
Water Pump Impeller with Key – Fits Mercury/Mariner 2-Stroke 50–60 HP and 4-Stroke 40–60 HP (Replaces 47-19453T, 47-19453, 18-8900) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller with key is a replacement cooling-system component for selected Mercury and Mariner outboards. The company fitment data covers 2-stroke 50, 55, and 60 HP models and selected 4-stroke 40, 50, and 60 HP models. The impeller is supplied with the matching key for installation and is intended to restore water-pump circulation when the original impeller is worn, cracked, brittle, or missing blades.
Use the original part number, engine model, stroke type, and serial-number range to confirm compatibility before ordering. Part-number references associated with this replacement include Mercury/Mariner 47-19453T and 47-19453, Sierra 18-8900, and Mallory 9-45301.
- Replacement water pump impeller for selected Mercury and Mariner outboards.
- Includes the required impeller key.
- High-volume/long-vane impeller reference with an outside diameter of approximately 3.125 inches and an inside diameter of approximately 0.75 inch.
- Aftermarket replacement part; not manufactured by Mercury, Mariner, Sierra, or Mallory.
Part Number Matrix
These are reference numbers associated with this impeller. Always verify the complete engine application before purchase.
| Brand | Part Number | Reference Type |
|---|---|---|
| Mercury/Mariner | 47-19453T | OEM reference |
| Mercury/Mariner | 47-19453 | OEM reference |
| Sierra | 18-8900 | Aftermarket reference |
| Mallory | 9-45301 | Aftermarket reference |
Engine & Model Compatibility
The company catalog identifies the following application groups. Fitment can vary by engine configuration and serial number, so match the complete model information and the original impeller number before installation.
| Brand | Stroke | Rated HP | Listed Models or Application |
|---|---|---|---|
| Mercury/Mariner | 2-Stroke | 50, 55, 60 | Selected 2-stroke outboards |
| Mercury/Mariner | 4-Stroke | 40 | 40 Carb, 3-cylinder; 40, 4-cylinder; 40 EFI, 4-cylinder |
| Mercury/Mariner | 4-Stroke | 50 | 50 EFI, 4-cylinder |
| Mercury/Mariner | 4-Stroke | 60 | 60, 4-cylinder; 60 EFI, 4-cylinder |
Technical Specs
- Product Type
- Water pump impeller with key
- Application
- Selected Mercury and Mariner 2-stroke and 4-stroke outboards
- 2-Stroke Fitment
- 50, 55, and 60 HP
- 4-Stroke Fitment
- 40, 50, and 60 HP applications listed above
- Impeller Style
- High-volume / long-vane reference
- Outside Diameter
- Approximately 3.125 in
- Inside Diameter
- Approximately 0.75 in
- Material
- Not specified in the company catalog
- Warranty
- Not specified for this product
What's in the Box
- 1 x Water pump impeller
- 1 x Impeller key
Gaskets, water-pump housing, wear plate, washers, and other service components are not included unless separately stated.
Installation Notes
- Confirm the engine model, stroke type, horsepower, serial number, and original impeller reference before beginning work.
- Disconnect the battery and follow the engine manufacturer's service procedure for removing the lower unit.
- Remove the water-pump housing and take note of the original impeller-vane orientation.
- Remove the old impeller, key, and any worn or damaged gaskets. Clean the housing and inspect it for scoring or excessive wear.
- Install the supplied key in the driveshaft keyway, then install the impeller with the vanes oriented as specified by the engine service manual.
- Reassemble the water-pump housing with suitable new gaskets or seals where required, using the manufacturer's specified bolt torque.
- Reinstall the lower unit and ensure the driveshaft, shift shaft, and water tube are correctly aligned.
- Run the engine only with an appropriate water supply and verify a strong tell-tale stream. Stop immediately if the engine overheats or water circulation is abnormal.
Troubleshooting & FAQ
How do I confirm this impeller fits my engine?
Compare the complete engine model, stroke type, horsepower, serial number, and original impeller part number with the compatibility information above. Horsepower alone is not sufficient to confirm fitment.
What are common signs of a worn impeller?
Common signs include a weak or missing tell-tale stream, overheating warnings, an unusually hot engine, or visible cracked, hardened, deformed, or missing vanes.
Does this product include the key?
Yes. The company product record identifies this item as an impeller with key, and one impeller key is included in the package.
Is this a complete water-pump kit?
No. This is an impeller-and-key replacement, not a complete water-pump service kit. The housing, gaskets, wear plate, washers, and other components are sold separately unless specifically listed.
Can I install it myself?
Installation requires removal of the lower unit and correct water-pump reassembly. Experienced boat owners may perform the service using the appropriate manual and tools; professional installation is recommended if you are unsure of the procedure.
Is this an OEM part?
No. This is an aftermarket replacement that references Mercury/Mariner 47-19453T and 47-19453, Sierra 18-8900, and Mallory 9-45301 for identification and compatibility.
What warranty is included?
A product-specific warranty is not stated in the available company catalog information. Contact the seller for current warranty and return-policy details.
Safety & Important Information
- Verify the exact engine model, stroke, horsepower, serial number, and original part number before ordering.
- Do not rely on horsepower or brand alone; similar engines may use different impellers.
- Do not run an outboard without an adequate water supply.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended when lower-unit removal or water-pump service is unfamiliar.
About Sea Sierra
- Marine Replacement Parts — Replacement components for routine outboard maintenance and repair.
- Application-Focused Cataloging — Product references are organized around engine model, stroke, horsepower, and part-number information.
- Support for Fitment Checks — Use the listed references and complete engine details to help select the correct replacement part.
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