Water Pump Repair Kit – Fits Mercury/Mariner Outboards & MerCruiser Alpha One (Replaces 46-96148Q8, 46-96148A8, 46-96148T8)

Water Pump Repair Kit – Fits Mercury/Mariner Outboards & MerCruiser Alpha One

This comprehensive water pump repair kit is designed for Mercury and Mariner outboards ranging from 65 HP (4-cylinder) through V-6 models equipped with short-vane impellers. It also fits MerCruiser I, R, MR, and Alpha One stern drives with serial numbers from 2491586 through 0D469858.

This kit serves as a direct replacement for Mercury part numbers 46-96148A8, 46-96148Q8, and 46-96148T8, along with several aftermarket equivalents, ensuring broad compatibility.

• Installation Type: Direct replacement for the upper water pump housing.
• Housing: Includes the black plastic upper pump housing assembly.
• Complete Kit: Contains all necessary gaskets, seals, and a new impeller for a standard service.

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 Outboards

MerCruiser Stern Drives

Technical Specifications

Package Contents

• 1 x Water Pump Impeller (47-89984T-3)
• 1 x Plastic Pump Housing Assembly
• 1 x Face Plate
• 1 x Gaskets (Set)
• 1 x Drive Key
• 1 x Face Seal
• 1 x Seal Carrier
• 1 x Water Tube Coupling
• 1 x O-rings (Set)
• 1 x Gear Lube Fill & Vent Screw Seals
• Note: This kit repairs the upper section of the water pump and does not include the water pump base.

Installation Guide

1. Disconnect the negative battery cable and remove the propeller.
2. Position a drain pan under the lower unit and remove the gear lube drain screw to drain the lubricant.
3. Remove the bolts securing the lower unit (gearcase) and carefully separate it from the upper housing.
4. Unbolt and lift the old water pump housing off the driveshaft. It may be tight.
5. Clean the mounting surfaces and remove the old impeller, drive key, and gaskets.
6. Install the new O-rings and seals in their correct positions.
7. Install the new drive key on the driveshaft flat and slide the new impeller on while turning the shaft clockwise to seat the vanes.
8. Apply a thin layer of gasket sealant to the new gaskets and install them.
9. Place the new housing over the impeller and tighten the bolts to the manufacturer's specified torque.
10. Re-install the lower unit, ensuring the water tube and driveshaft align correctly.
11. Refill the gearcase with the recommended marine gear lubricant before starting.
12. Connect a water supply, start the engine, and immediately check for a steady stream a water from the tell-tale port.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my specific engine?
A: This kit is designed for a wide range of Mercury/Mariner outboards (65HP+ 4-cyl through V6 models) and MerCruiser Alpha One stern drives with serial numbers between 2491586 and 0D469858. The best way to confirm fitment is to check your engine's original part number against the numbers listed in our Part Number Cross-Reference table, such as 46-96148A8 or 46-96148Q8.

Q: Does this kit include the lower water pump base?
A: No, this kit is specifically for servicing the upper section of the water pump. It includes the plastic upper housing, impeller, face plate, and seals but does not contain the lower pump base.

Q: How often should I replace my water pump impeller?
A: For preventative maintenance, we recommend inspecting your water pump annually and replacing the impeller and gaskets every 1-2 years or 100-200 hours of operation. This interval can be shorter if you frequently operate in salt water or silty conditions.

Q: What are the signs of a failing water pump?
A: The most common signs are the engine running hotter than normal or a weak/non-existent water stream from the "tell-tale" outlet port. Upon inspection, you might find the impeller vanes are cracked, brittle, or have broken off.

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.