Water Pump Impeller Repair Kit – Fits Mercury/Mariner 30-125 HP (Replaces 46-8M0113799, 46-43024A7)

Water Pump Impeller Repair Kit – Fits Mercury/Mariner 30-125 HP (Replaces 46-8M0113799, 46-43024A7)

This water pump impeller repair kit is designed for a wide range of Mercury and Mariner 2-stroke and 4-stroke outboard engines from 30 HP to 125 HP, covering various models from the 1990s through the 2020s. It provides the essential components needed to service your engine's water pump and restore its cooling performance.

This kit is a direct replacement for Mercury part numbers 46-8M0113799 and the superseded part number 46-43024A7. It also serves as an aftermarket replacement for Sierra part number 18-3688.

• Engineered as a direct replacement part for straightforward installation.
• High-quality aftermarket kit built to meet or exceed original equipment specifications.
• Restores cooling system efficiency to prevent engine overheating.

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.

Technical Specifications

Installation Guide

1. Disconnect the negative battery cable. Locate and unbolt the lower unit (gearcase) from the engine's midsection.
2. Carefully lower and remove the gearcase to expose the water pump assembly on top of it.
3. Remove the bolts securing the water pump housing cover. Slide the housing up and off the driveshaft.
4. Take note of the old impeller's vane direction before removing it. Remove the old impeller, key, gaskets, and O-rings.
5. Thoroughly clean the inside of the pump housing and the base plate, removing any old gasket material or debris.
6. Install the new gaskets and O-rings as supplied in the kit.
7. Slide the new impeller key into the driveshaft slot.
8. Install the new impeller by pushing it down over the key while turning the driveshaft clockwise to bed the vanes correctly.
9. Reinstall the water pump housing and tighten the bolts to the manufacturer's specified torque.
10. Carefully guide the lower unit back into position, ensuring the driveshaft, shift shaft, and water tube are correctly aligned.
11. Secure the lower unit with its mounting bolts and refill the gearcase with fresh lubricant.
12. Once assembled, test the engine using a water supply (flushing muffs) to confirm a strong water stream from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this fits my engine?
Verify your engine's model, horsepower, and serial number range against the detailed compatibility table above. For Mercury owners, use the provided Serial Number Guide to confirm your details before ordering.

What are the signs of a failing water pump impeller?
Common symptoms include the engine overheating, a weak or absent water stream from the "tell-tale" outlet, or in severe cases, a melted plastic water pump housing. Regular inspection is key.

How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of operation. Service intervals should be shorter in saltwater or silty conditions.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.