Water Pump Base – Fits Mercury/Mariner 30-60 HP & Force 70-75 HP (Replaces 46-812966A7)

Water Pump Base – Fits Mercury/Mariner 30-60 HP & Force 70-75 HP (Replaces 46-812966A7)

This water pump base is designed for a precise fit on a range of Mercury/Mariner and Force outboard engines. It is compatible with Mercury/Mariner 30-60 HP 2-stroke and 4-stroke models from 1991 and newer, covering 3 & 4 cylinder and EFI variants. It also fits Force 70 HP (1991-1995) and 75 HP (1996-1998) 2-stroke outboards.

This component serves as a direct replacement for Mercury part numbers 46-812966A7, 46-812966A9, and 46-81266A3, as well as aftermarket equivalents like Sierra 18-3445, GLM 12352, and Mallory 9-43330.

• Direct Replacement: Installs without modifications, matching OEM specifications.
• Durable Construction: Manufactured from high-quality stainless steel for corrosion resistance and longevity.
• Critical Component: Restores the integrity of the water pump assembly for reliable engine cooling.

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 Water Pump Base (Replaces 46-812966A7)

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is tilted up and secured.
2. Access the Lower Unit: Remove the bolts securing the lower unit (gearcase) to the engine's midsection.
3. Remove the Lower Unit: Carefully lower the gearcase away from the engine. The driveshaft will disengage from the powerhead.
4. Disassemble Pump Housing: Unbolt and remove the existing water pump housing, followed by the impeller and wear plate.
5. Remove Old Base: With the housing removed, unbolt and detach the old water pump base.
6. Clean Surfaces: Thoroughly clean the mounting surface on the gearcase, removing any old gasket material or sealant residue.
7. Install New Base: Place the new water pump base onto the gearcase, ensuring it is properly aligned. Secure it with the original bolts.
8. Reassemble Pump: Install a new wear plate, impeller (with key), and housing according to your service manual's specifications.
9. Reinstall Lower Unit: Guide the driveshaft back into the engine and reinstall the lower unit, securing it with its bolts.
10. Final Checks: Reconnect the battery. Start the engine in a safe environment (with water supplied to the lower unit) and check for proper water output from the tell-tale stream.

Troubleshooting & FAQ

Q: How do I confirm this part fits my specific engine model?

A: The most reliable method is to match the OEM part number (46-812966A7) with your engine's service manual or parts diagram. You can also use our compatibility tables by checking your engine's brand, model, horsepower, and year. For Mercury owners, we recommend using the serial number guide linked above to verify your model details, as year ranges can sometimes overlap.

Q: What are the common signs that a water pump base needs replacement?

A: A failing water pump base can cause the entire pump assembly to lose its seal, leading to low water pressure and engine overheating. Visual signs include visible cracks, warping, or corrosion on the old base during an inspection. If you are replacing the impeller, it is always a good practice to inspect the base and housing for wear.

Q: How does the material of this aftermarket base compare to the OEM part?

A: This base is manufactured to meet or exceed OEM specifications, using high-quality stainless steel for excellent durability and resistance to corrosion in marine environments. The materials are chosen to provide a reliable, long-lasting service life comparable to the original factory part.

Q: OEM vs. Aftermarket?

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.