Water Pump Impeller – Fits Mercury/Mariner/Honda 40-300HP (Replaces 47-43026T2)
Water Pump Impeller – Fits Mercury/Mariner/Honda 40-300HP (Replaces 47-43026T2) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
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Water Pump Impeller – Fits Mercury/Mariner/Honda 40-300HP (Replaces...
Water Pump Impeller – Fits Mercury/Mariner/Honda 40-300HP (Replaces 47-43026T2) is backordered and will ship as soon as it is back in stock.
Product Details
This high-quality Water Pump Impeller – Fits Mercury/Mariner/Honda 40-300HP (Replaces 47-43026T2) is a critical service part for maintaining your engine's cooling system. It is engineered for a wide range of Mercury/Mariner outboards from 40 to 300HP, MerCruiser Alpha I (Gen 2) and Vazer sterndrives, and select Honda outboard models.
This component serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 47-43026T2, Sierra 18-3056, Mallory 9-45037, and EMP 47-01814.
- Designed for direct, hassle-free installation.
- Constructed from a durable rubber compound with a metal hub for longevity.
- Resistant to engine heat and abrasive wear in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 47-43026T2 |
| Sierra | 18-3056 |
| Mallory | 9-45037 |
| EMP | 47-01814 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury/Mariner owners: This impeller fits a variety of 3 and 4-cylinder outboards, including Bigfoot models, as well as Alpha One Generation 2 sterndrives.
For Honda owners: This part is confirmed compatible with specific Honda outboards. Please check your service manual for OEM part number interchange with Mercury 47-43026T2.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | Outboard | 30/40/45/50/60 | 4-Stroke | Bigfoot models | 47-43026T2 | |
| MerCruiser | Alpha I-Gen 2 | s/n D494569 & above | 47-43026T2 |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct replacement
- Housing Material
- Rubber with metal hub
- Dimensions
- OD: 89mm, ID: 22.4mm, Width: 32.5mm
- Number of Blades
- 6
- Key Required
- Yes (28-32833)
- Other Technical Attributes
- Resistant to heat and wear
What’s in the Box
- 1 x Water Pump Impeller (47-43026T2)
Installation Notes
- Disconnect the negative battery cable for safety.
- Remove the lower unit (gearcase) from the outboard or sterndrive.
- Locate and unbolt the water pump housing cover.
- Carefully slide the old impeller off the driveshaft, noting its orientation. Remove the drive key.
- Clean any old gasket material or debris from the housing and wear plate surfaces.
- Place the new gasket and wear plate (if included in your kit) into position.
- Insert the new key into the driveshaft keyway.
- Lubricate the inside of the pump housing and the new impeller with a marine-safe lubricant.
- Slide the new impeller onto the shaft while turning the shaft clockwise to bed the blades correctly.
- Re-install the water pump housing and tighten bolts to the manufacturer's specified torque.
- Re-attach the lower unit, ensuring the driveshaft and water tube are correctly aligned.
- After reassembly, test the engine in the water to verify proper cooling system operation.
Troubleshooting & FAQ
How do I know if this impeller is the right one for my engine?
The best method is to match your existing part number to one in our Part Number Matrix. If you don't know the part number, check the Engine Compatibility table. Always visually compare your old part to our photos before ordering.
What are the signs of a failing water pump impeller?
Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent "telltale" water stream, or a high temperature alarm. Brittle, cracked, or missing impeller blades upon inspection are definitive signs of failure.
How often should I change my impeller?
As a general maintenance guideline, impellers should be inspected annually and replaced every 1-2 years, regardless of engine hours. In sandy or silty water conditions, more frequent replacement is recommended.
Is a keyway required for this impeller?
Yes, this impeller requires a drive key (part number 28-32833) to lock it to the driveshaft. Ensure your old key is in good condition or purchase a new one for installation.
Is this an OEM part?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for consistency.
How fast is shipping and what does it cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options will appear at checkout where available for your location.
What is the warranty and return policy?
This part is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter any issues, 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/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 quality control.
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