Water Pump Impeller Repair Kit – Fits Mercury/Mariner Outboards 65–225 HP and MerCruiser Alpha One Gen I (Replaces 96148Q8, 96148A8)

Product Details

This Water Pump Impeller Repair Kit is a service component for the cooling systems of selected Mercury and Mariner outboards and MerCruiser stern drives. It is intended for 2-stroke Mercury and Mariner outboards in the 65–225 HP range, including selected 4-cylinder and V6 models, and for selected MerCruiser I, R, MR, and Alpha One Gen I drives. Always verify the exact model, year, serial-number range, and original pump configuration before ordering.

The kit is listed as a replacement for several Mercury and aftermarket reference numbers, including Mercury 46-96148Q8, 96148A8, 96148A5, Sierra 18-3517, and Mallory 9-48311. These references should be used together with the compatibility information below rather than as a substitute for model and serial-number verification.

• Installs in the lower unit or outdrive water-pump assembly.
• Includes a plastic pump housing, impeller, and face plate for a water-pump service repair.
• Designed for applications using the corresponding short-vane impeller configuration.
• Replacing a worn impeller can help restore proper cooling-water circulation.

Part Number Matrix

The following numbers are reference listings associated with this replacement kit or its applicable pump components. Confirm the original part and application before purchase.

Engine and Model Compatibility

The applications below are reference fitments for selected 2-stroke Mercury and Mariner outboards. Model, year, serial number, and pump configuration must be checked together. An engine model appearing in this table does not by itself confirm fitment for every production year or serial range.

MerCruiser Stern Drive Compatibility

This kit is listed for selected legacy MerCruiser I, R, MR, and Alpha One Gen I stern drives. The serial-number range is especially important for the later R, MR, and Alpha One applications.

Technical Specifications

Product Type

Water pump impeller repair kit

Installation Location

Lower unit or stern-drive outdrive water-pump assembly

Housing Material

Plastic

Housing Color

Black

Weight

0.37 kg (0.82 lb)

Application

Selected Mercury/Mariner 2-stroke outboards and MerCruiser stern drives using the corresponding pump configuration

What's in the Box

• 1 × Water pump impeller, reference 89984T4
• 1 × Plastic pump housing, reference 96148A1
• 1 × Face plate, reference 8M0204677

Installation Notes

1. Disconnect the battery and remove the spark plug leads before beginning work.
2. Place the outboard or stern drive in a stable position that provides access to the lower unit.
3. Drain the gearcase lubricant by removing the fill and vent plugs.
4. Remove the propeller assembly as required for access.
5. Loosen and remove the bolts securing the lower unit or gearcase to the midsection.
6. Separate the lower unit carefully, paying close attention to the shift shaft and water-tube alignment.
7. Remove the old water-pump housing assembly and note the orientation of each component.
8. Clean the mounting surfaces and inspect the driveshaft, keyway, seals, and related pump components for wear or damage.
9. Install the replacement components in the correct order. Lightly lubricate the impeller with a suitable water-soluble lubricant before assembly.
10. Reinstall the lower unit, ensuring that the water tube and shift shaft are correctly aligned.
11. Tighten all fasteners to the manufacturer's specifications, refill the gear lubricant, and reinstall the propeller.
12. Run the engine using an appropriate water supply and verify a steady tell-tale stream and normal operating temperature.

Troubleshooting and FAQ

Safety and Important Information

• Verify the original part number, dimensions, configuration, model, year, and serial number before purchase.
• Do not operate the engine without an adequate cooling-water supply.
• Follow the engine or drive manufacturer's service procedures and torque specifications.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safe and reliable operation.

About Sea Sierra

• Marine Replacement Parts — We supply replacement components for common outboard and stern-drive service applications.
• Application-Focused Listings — Product references and compatibility information are provided to help customers compare the original component before ordering.
• Customer Support — When fitment is uncertain, provide the engine or drive model, serial number, and original part details for application assistance.