Water Pump Impeller Kit – Fits Mercury/Mariner 4-Stroke 30-70 HP (Replaces 46-812966A12)

Water Pump Impeller Kit – Fits Mercury/Mariner 4-Stroke 30-70 HP (Replaces 46-812966A12)

This water pump impeller kit provides a complete solution for servicing the cooling system on Mercury/Mariner 4-Stroke 30, 40, 50, 60, and 70 HP outboard engines (1991 and newer models).

It is engineered to serve as a direct replacement for Mercury/Quicksilver part numbers 46-812966A12, 46-812966A11, and 46-812966A10, as well as aftermarket equivalents from Sierra, GLM Marine, and others.

• Complete Kit: Includes the impeller, housing, base, gaskets, plate, and all necessary hardware for a full replacement.
• Direct Fit: Designed as a direct replacement for the original equipment manufacturer (OEM) part for a straightforward installation.
• Critical Maintenance: Essential for maintaining engine cooling system integrity, preventing overheating and ensuring long-term engine health.

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

Package Contents

• 1 x Impeller (47-19453T)
• 1 x Base (46-812966A7)
• 1 x Guide tube/Coupler (859770/859770-1/893857)
• 1 x Impeller Key
• 1 x O-Ring
• 1 x Washer (12-858234)
• 1 x Plate (19700A2)
• 1 x Gasket Upper (27-822189)
• 1 x Gasket Lower (27-19701)
• 1 x Housing

Explosion Diagram

Installation Guide

1. Disconnect the negative battery cable and remove the engine Cowling.
2. Shift the outboard into forward gear to simplify driveshaft re-engagement later.
3. Remove the bolts securing the lower unit (gearcase) to the engine's midsection and carefully lower it.
4. Unscrew the bolts on the water pump housing and lift the housing off the driveshaft.
5. Remove the old impeller, key, wear plate, and gaskets. Thoroughly clean all mating surfaces, removing any old gasket material or debris.
6. Install the new lower gasket and wear plate onto the gearcase.
7. Insert the new impeller key into the slot on the driveshaft.
8. Apply a thin layer of marine grease or soap-water solution to the new impeller and the inside of the new housing.
9. Slide the new impeller onto the driveshaft while turning the shaft clockwise to correctly orient the vanes.
10. Place the new housing and upper gasket over the impeller and secure it with the bolts, tightening them to the torque specified in your service manual.
11. Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are properly aligned. Secure with the mounting bolts.
12. Reconnect the battery. Start the engine using a water supply (flushing muffs) and confirm a steady stream of water from the tell-tale port.

Troubleshooting & FAQ

How do I confirm this kit fits my Mercury engine?

This kit fits most Mercury and Mariner 4-stroke outboards from 30 to 70 HP (1991 and newer). The best way to confirm is by checking your engine's serial number against the ranges listed in our compatible models table. Cross-referencing your old part number with our list (e.g., 46-812966A12) is also a reliable verification method.

What are the signs that my water pump impeller needs replacement?

Common symptoms of a failing impeller include a weak or non-existent water stream from the tell-tale outlet, the engine overheating alarm sounding, or discovering cracked, brittle, or deformed rubber vanes during a visual inspection.

How often should I replace the water pump impeller?

For preventative maintenance, we recommend inspecting the impeller annually and replacing it every 1-2 years or every 100-200 hours of engine use. If you frequently operate in shallow, sandy, or debris-filled water, more frequent replacement is advised.

Is the housing included in this kit?

Yes, this is a complete water pump service kit that includes the impeller, the pump housing, a new wear plate, all necessary gaskets, and required hardware for a full overhaul.

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.