Water Pump Impeller Kit – Fits Mercury/MerCruiser 35-300 HP
This water pump impeller service kit is designed for a wide range of Mercury/Mariner outboards from 35 HP to 300 HP and MerCruiser Alpha One Gen 2 sterndrives with serial numbers 0D469859 and above. It provides a reliable, direct-fit solution for maintaining your engine’s cooling system.
This kit is a direct replacement for Mercury/Quicksilver part numbers 8M0100526 and 47-43026Q06, as well as Sierra 18-3265 and UANOFCN 8M0100526.
- Engineered for improved water flow and cooling efficiency.
- Constructed with a durable Neoprene marine rubber impeller, stainless steel faceplate, and non-asbestos gaskets.
- Includes all necessary gaskets, seals, and O-rings for a complete water pump rebuild.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
Brand |
Part Number |
Mercury/Quicksilver |
8M0100526 |
Mercury/Quicksilver |
47-43026Q06 |
Sierra |
18-3265 |
UANOFCN |
8M0100526 |
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.
Mercury/Mariner Outboard
Brand |
Model |
Rated HP |
Stroke |
OEM Part No. |
Notes |
Mercury |
BigFoot/Command Thrust |
40-60 |
4-Stroke |
8M0100526, 47-43026Q06 |
|
Mercury |
BigFoot |
60 |
2-Stroke |
8M0100526, 47-43026Q06 |
Serial #0D000750 and above |
Mercury |
FourStroke |
75-115 |
4-Stroke |
8M0100526, 47-43026Q06 |
All models |
Mercury |
FourStroke |
150 |
4-Stroke |
8M0100526, 47-43026Q06 |
All models |
Mercury |
Standard |
70-90 |
2-Stroke |
8M0100526, 47-43026Q06 |
Serial #0A996142 and above |
Mercury |
Standard |
100-125 |
2-Stroke |
8M0100526, 47-43026Q06 |
4 cylinder models with pump cover screws without insulators |
Mercury |
OptiMax |
200/225/250 |
2-Stroke |
8M0100526, 47-43026Q06 |
3.0L V6 models |
Mercury |
Verado |
|
4-Stroke |
8M0100526, 47-43026Q06 |
L4 & L6 models with 4.80" & 5.44" diameter gearcases |
Mercury |
Various Outboard Models |
35-300 |
2-Stroke & 4-Stroke |
8M0100526, 47-43026Q06 |
Model specific - verify application |
MerCruiser Sterndrive
Brand |
Model |
OEM Part No. |
Notes |
MerCruiser |
Alpha One Gen 2 |
8M0100526, 47-43026Q06 |
Serial #0D469859 and above |
MerCruiser |
Gear Housing Drive-2.33:1 |
8M0100526, 47-43026Q06 |
USA-0T625304/BEL-0P216185 and up |
Technical Specifications
Specification |
Value |
Product Type |
Water Pump Impeller Kit |
Installation |
Direct replacement |
Housing Material |
Non-asbestos gasket, Neoprene Marine Rubber Impeller and O-Ring, Stainless Steel Plate |
Housing Color |
Black/Silver |
Other Technical Attributes |
Designed for improved water flow rate and cooling efficiency |
Package Contents
- 1 x Water Pump Impeller (8M0025709)
- 1 x Water Pump Faceplate (8172761)
- 1 x Face Seal (8M2014338)
- 1 x Quad Ring (455771)
- 1 x Impeller Gasket (8M0050720)
- 1 x Impeller Key (8M0032833)
- 1 x Seal Ring Gasket (8172771)
- 1 x Drain Screw Gasket (830749)
- 2 x O-Ring (0.796 in. x 0.139 in.) (21836)
- 1 x O-Ring (0.921 in. x 0.139 in.) (90196)
- 1 x Face Seal Setting Tool (818769)
Explosion Diagram
Installation Guide
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Disconnect Power: Disconnect the battery and shift the outboard into neutral.
-
Access the Lower Unit: Remove the bolts securing the lower unit (gearcase) to the upper leg of the outboard.
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Remove the Old Pump: Carefully lower the gearcase. The water pump housing is located on top of the gearcase. Remove the bolts securing the water pump housing.
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Inspect and Clean: Remove the old impeller and gaskets. Clean the housing and faceplate surfaces thoroughly, ensuring they are free of old gasket material and corrosion.
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Install New Components: Lightly grease the new impeller and insert it into the housing, rotating the driveshaft clockwise to seat the vanes correctly. Install the new key, gaskets, and seals.
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Reassemble Pump Housing: Secure the new faceplate and housing with the provided bolts, tightening them to the manufacturer's specified torque.
-
Reattach Lower Unit: Re-install the lower unit, ensuring the driveshaft, shift shaft, and water tube align correctly. Secure with bolts.
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Test Operation: Reconnect the battery and start the engine using a water supply (flushing muffs) to verify proper water flow from the tell-tale outlet.
Troubleshooting & FAQ
Q: How do I confirm this kit fits my specific engine?
A: The best way is to check the part number on your original water pump or in your service manual. Compare it to the cross-reference list provided (8M0100526, 47-43026Q06). You should also verify your engine model and serial number against the compatibility tables above.
Q: What are the signs of a failing water pump impeller?
A: Common signs include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, or a cracked and brittle appearance on the old impeller's vanes during inspection.
Q: How often should I replace my water pump 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 (especially in saltwater or sandy/silty water).
Q: Is this an OEM part?
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.