Water Pump Impeller Kit – Fits Mercury/MerCruiser 35-300 HP (Replaces 47-8M0100526, 47-43026Q06)

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.

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

MerCruiser Sterndrive

Technical Specifications

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

1. Disconnect Power: Disconnect the battery and shift the outboard into neutral.
2. Access the Lower Unit: Remove the bolts securing the lower unit (gearcase) to the upper leg of the outboard.
3. 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.
4. 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.
5. 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.
6. Reassemble Pump Housing: Secure the new faceplate and housing with the provided bolts, tightening them to the manufacturer's specified torque.
7. Reattach Lower Unit: Re-install the lower unit, ensuring the driveshaft, shift shaft, and water tube align correctly. Secure with bolts.
8. 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?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.