Water Pump Impeller Repair Kit for Mercury Outboards and MerCruiser Alpha One (Replaces 46-96148A8, 46-96148Q8)

Product Details

This aftermarket water pump impeller repair kit is designed for selected Mercury outboard water-pump applications and MerCruiser sterndrive systems using the large plastic water-pump housing configuration. It is intended for cooling-system service when the impeller, housing, wear surfaces, gaskets, or seals require replacement.

Catalog references associate the applicable water-pump assembly with Mercury outboards from approximately 65 through 225 HP in selected applications and with MerCruiser MC-1, R, MR, and Alpha One units. Fitment depends on the exact model, engine configuration, and serial-number range. Always compare the original water-pump assembly and verify the serial number before ordering.

• Aftermarket repair kit for selected Mercury and MerCruiser water-pump applications.
• Includes the upper pump housing and related service components shown in the package list below.
• Neoprene impeller is intended to restore water-pump flow when the original impeller is worn, cracked, hardened, or damaged.
• Designed for applications corresponding to the large plastic housing associated with Mercury reference 46-96148A8.

Reference Part Numbers

The following numbers are catalog and aftermarket reference numbers associated with this water-pump application. They are provided for comparison only and do not replace model and serial-number verification.

Mercury Outboard Compatibility

Available catalog evidence places the 46-96148A8 water-pump application on selected Mercury outboards, including the model and serial-number examples below. These entries should be treated as application guides rather than universal fitment for every engine carrying the same horsepower rating.

Additional catalog references indicate selected Mercury applications through approximately 225 HP, generally within older 2-stroke model ranges. Horsepower alone is not sufficient to confirm fitment; compare the original housing, plate, impeller, drive key, and serial-number range.

MerCruiser Sterndrive Compatibility

This water-pump application is associated with selected MerCruiser MC-1, R, MR, and Alpha One sterndrives. Some reference listings identify Alpha One applications from approximately 1983–1990, while other catalogs list serial-number-specific applications. Confirm the sterndrive serial number and water-pump configuration before installation.

Technical Specifications

Product Type

Aftermarket water pump impeller repair kit

Primary Application

Selected Mercury outboards and MerCruiser sterndrive water-pump systems

Housing Style

Large plastic water-pump housing application

Housing Material

Nylon PA66 plastic, as listed for the aftermarket housing

Impeller Material

Neoprene rubber

Approximate Base Size

2.356 inches (59.8 mm), as listed for this application

Approximate Product Weight

330 grams (0.73 lb), as listed for this application

Fitment Requirement

Exact model, configuration, housing style, and serial-number verification required

What's Included

This repair kit is supplied with the following service components:

• 1 × water-pump impeller
• 1 × upper pump housing
• 1 × face plate
• 1 × drive key or impeller pin
• 1 × face seal
• 1 × seal carrier
• 1 × water-tube coupling
• 1 × gasket set
• 1 × O-ring set
• 2 × gear-lubricant fill and vent screw seals

Not included: the water-pump base. The included housing and components are intended for a repair configuration that uses the existing compatible base and lower-unit components.

Installation Notes

1. Disconnect the battery and prevent accidental engine starting.
2. Place the engine or sterndrive in a safe service position and follow the manufacturer’s procedure for lower-unit removal.
3. Remove the lower unit and expose the water-pump assembly.
4. Remove the pump housing, impeller, face plate, gaskets, seals, and drive key. Note the original impeller-vane orientation.
5. Clean all mating surfaces and remove old gasket material, corrosion, and debris.
6. Install the new gasket, face plate, drive key, and impeller. Use a suitable marine lubricant and rotate the driveshaft in the manufacturer-specified direction while seating the impeller vanes.
7. Install the replacement housing, seals, coupling, and remaining components. Tighten fasteners to the engine or sterndrive manufacturer’s specifications.
8. Reinstall the lower unit, ensuring correct alignment of the water tube, driveshaft, and shift mechanism.
9. Run the engine only with an appropriate water supply. Check for a steady cooling-water discharge and monitor engine temperature.

Maintenance and Troubleshooting

Safety and Important Information

• Do not rely on horsepower alone for fitment. Confirm the exact model, configuration, housing style, and serial number.
• Compare the original parts and the product images before installation.
• Do not operate an outboard or sterndrive without an adequate water supply.
• Use the manufacturer’s service manual for torque values, shift-shaft procedures, and final testing.
• Professional installation is recommended when lower-unit removal or shift-linkage adjustment is required.

About Sea Sierra

• Marine Replacement Parts — Practical aftermarket components for routine service and repair.
• Application-Focused Listings — Reference numbers and fitment guidance are provided to support compatibility checks.
• Service-Ready Kits — Replacement components are grouped for common water-pump maintenance tasks.