Water Pump Impeller Kit – Fits Mercury/Mariner 75-115HP 4-Stroke (Replaces 817275A5, 46-817275Q05)
Water Pump Impeller Kit – Fits Mercury/Mariner 75-115HP 4-Stroke (Replaces 817275A5, 46-817275Q05) 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 Kit – Fits Mercury/Mariner 75-115HP 4-Stroke (R...
Water Pump Impeller Kit – Fits Mercury/Mariner 75-115HP 4-Stroke (Replaces 817275A5, 46-817275Q05) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit provides a comprehensive solution for servicing the cooling system on Mercury/Mariner 4-stroke outboards from 75HP to 115HP (including 1596cc, 1731cc, and 2.1L models) manufactured from 2004 to the present. The kit is engineered as a direct-fit replacement to restore cooling performance and prevent engine overheating.
It interchanges with Mercury part numbers 46-817275A5, 46-817275Q05, 817275K05, 817275A10, and Sierra aftermarket parts 18-3147 and 18-3406.
- Installs as a direct OEM-equivalent replacement.
- Includes all essential components: impeller, housing, face plate, gaskets, and hardware.
- Constructed from durable metal alloy and neoprene rubber for longevity in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 46-817275A5 |
| Mercury | 46-817275Q05 |
| Mercury | 817275K05 |
| Mercury | 817275A10 |
| Sierra | 18-3147 |
| Sierra | 18-3406 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit fits specific Mercury and Mariner FourStroke engines. Please note the distinction between pre-2015 and 2015+ models, which use different OEM part-number series but are covered by this single kit.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | FourStroke | 75 | 4-Stroke | 2004–2015 | 817275A5 | 1596cc/1731cc engines |
| Mercury | FourStroke | 80 | 4-Stroke | 2004–2015 | 817275A5 | 1596cc/1731cc engines |
| Mercury | FourStroke | 90 | 4-Stroke | 2004–2015 | 817275A5 | 1596cc/1731cc engines |
| Mercury | FourStroke | 100 | 4-Stroke | 2004–2015 | 817275A5 | 1596cc/1731cc engines |
| Mercury | FourStroke | 115 | 4-Stroke | 2004–2015 | 817275A5 | 1741cc/1731cc engines |
| Mercury | FourStroke | 75/80 | 4-Stroke | 2015+ | 817275A10 | 2.1L engines |
| Mercury | FourStroke | 90/100 | 4-Stroke | 2015+ | 817275A10 | 2.1L engines |
| Mercury | FourStroke | 115 | 4-Stroke | 2015+ | 817275A10 | 2.1L engines |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Direct OEM replacement
- Housing Material
- Metal alloy and neoprene rubber
- Kit Contents
- Complete water pump kit with impeller, housing, face plate, gaskets, and hardware
What’s in the Box
- 1 x Water Pump Impeller (47-43026T2)
- 1 x Housing
- 1 x Face Plate
- 1 x Gasket
- 1 x Grommets
- 1 x Seal
- 1 x Cover
- 1 x Washer
- 1 x O-ring
- 1 x Impeller Key
Installation Notes
- Ensure the engine is off and the battery is disconnected. Place the outboard in a secure, tilted position.
- Drain the gearcase oil from the lower unit into a suitable container.
- Remove the mounting bolts connecting the lower unit (gearcase) to the upper driveshaft housing.
- Carefully separate the lower unit from the engine assembly. You may need to disconnect the shift shaft linkage.
- Unbolt and remove the old water pump housing. Note the orientation of the old impeller vanes.
- Remove the old impeller, key, gaskets, and wear plate. Thoroughly clean all mating surfaces.
- Install the new wear plate, gaskets, and impeller key. Slide the new impeller on while turning the driveshaft clockwise to set the vanes correctly.
- Apply a light coat of marine grease to the inside of the new housing and install it over the impeller.
- Torque the housing bolts to the manufacturer's specifications.
- Reassemble the lower unit to the engine, ensuring the driveshaft, water tube, and shift shaft align correctly.
- Refill the gearcase with fresh marine gear lube and reinstall the battery connection.
- Once assembled, test the engine using a water source (flushing muffs) to confirm proper water flow.
Troubleshooting & FAQ
How do I confirm this kit fits my specific engine?
Your primary reference should be the engine compatibility table. Match your engine's brand, model, horsepower, and year range. For absolute certainty, cross-reference the OEM part number listed in the table with your engine's service manual.
What are the signs of a failing water pump impeller?
Common signs include a weak or inconsistent stream of water from the engine's tell-tale port, rising engine temperatures at idle or low speeds, and an overheating alarm. A visual inspection may show cracked, brittle, or missing impeller vanes.
How often should the water pump impeller be replaced?
As a general maintenance guideline, impellers should be inspected annually and replaced every 2-3 years, or every 200-300 hours of operation. This interval can be shorter if the engine is used frequently in sandy, silty, or saltwater conditions.
Is this a complete kit for the job?
Yes, this kit includes all the necessary standard components for a water pump service: the impeller, housing, face plate, gaskets, seals, and related hardware. No other parts are typically required.
What's the difference between the 'A5' and 'A10' OEM part numbers?
The part numbers 817275A5 and 817275A10 correspond to different production runs and engine displacements (pre-2015 vs. 2015+ 2.1L engines, respectively). This aftermarket kit is designed to be compatible with both series, covering the full 2004 to present year range.
Do I need special tools for installation?
Basic hand tools like a socket/ratchet set, screwdrivers, and pliers are required. A torque wrench is highly recommended to tighten bolts to the manufacturer's specifications, and a gear lube pump will be needed to refill the lower unit.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in 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 QC.
Payment & Security
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