Water Pump Repair Kit – Fits Mercury/Mariner Outboards 75-225HP & MerCruiser Alpha One Stern Drives (Replaces 96148Q8, 46-96148A8)

Water Pump Repair Kit – Fits Mercury/Mariner Outboards 75-225HP & MerCruiser Alpha One Stern Drives

This water pump repair kit provides the essential components needed to restore the cooling system on a wide range of Mercury/Mariner outboards and MerCruiser stern drives. It is designed for 75-225HP 2-Stroke outboards (4-cylinder and V6 models) and MerCruiser Pre-Alpha, R, MR, and Alpha One stern drives (1970-1990) within the serial number range 2495186 to 0D469858.

Engineered as a direct replacement for multiple OEM part numbers, this kit ensures a precise fit and restores cooling performance. It is cross-compatible with Mercury parts 46-96148A8, 96148Q8, 96148T8, 96148B8, 96148A5, and Sierra parts 18-3217, 18-3316, 18-3517.

• Complete Kit: Includes a neoprene rubber impeller, housing, gaskets, seals, and other necessary hardware for a full replacement.
• Durable Materials: Features a marine-grade key plate, nylon PA66 plastic housing, and neoprene seals for longevity in marine environments.
• Direct Installation: Designed to fit the original water pump housing without modifications; follow your factory service manual for installation.

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 (Replaces 46-96148A8)
• 1 x Impeller Housing
• 1 x Impeller Key
• 1 x Face Plate
• 2 x Gaskets
• 1 x Seal
• 1 x Water Tube Guide Sleeve
• 1 x O-ring
• 2 x Drain Plug Washers

Installation Guide

1. Disconnect Power: Disconnect the battery before starting work.
2. Drain Gear Lube: Drain the gear lube from the lower unit.
3. Remove Lower Unit: Unbolt and carefully detach the lower unit (gearcase) from the outboard leg.
4. Access Pump: Locate and unbolt the water pump housing.
5. Remove Old Components: Remove the old housing, impeller, wear plate, gaskets, and seals. Note their orientation.
6. Clean Surfaces: Thoroughly clean all mating surfaces, ensuring they are free of old gasket material and corrosion.
7. Install New Components: Install the new gaskets, wear plate, and impeller key.
8. Install Impeller: Slide the new impeller onto the driveshaft. Rotate the shaft clockwise while pushing down to seat the vanes correctly inside the housing.
9. Secure Housing: Install the new housing and torque the bolts to the manufacturer's specified values.
10. Reinstall Lower Unit: Reattach the lower unit to the engine leg and tighten all bolts securely.
11. Refill and Test: Refill the lower unit with fresh gear lube. Reconnect the battery and test the engine's cooling system operation in water, checking for a strong tell-tale stream.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my Mercury engine?

A: Check the serial number of your engine. This kit fits specific serial ranges for 75-225HP 2-stroke outboards and MerCruiser Alpha One stern drives from 1970-1990 (serial #2495186-0D469858). Always refer to the detailed compatibility tables on this page to verify your specific model and serial number before ordering.

Q: What are the signs my water pump is failing?

A: Common signs of a failing water pump include the engine overheating (especially at idle or low speeds), a weak or non-existent water stream from the "telltale" outlet, or finding a brittle, cracked, or deformed impeller during a routine inspection.

Q: How often should I replace the water pump impeller?

A: For preventative maintenance, it is highly recommended to replace the water pump impeller every 1 to 2 years, or every 100-200 hours of operation. The interval may vary based on usage (e.g., saltwater vs. freshwater) and operating conditions.

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.