Water Pump Service Kit – Fits Mercury/Mariner 75-220 HP Outboards & MerCruiser I/R/MR/Alpha (Replaces 96148A8)
This water pump service kit is designed for Mercury/Mariner 65-220 HP 2-Stroke outboards with short-vane impellers. It also fits MerCruiser I, R, MR, and Alpha sterndrives within the serial number range of 2491586 to 0D469858.
This is a direct aftermarket replacement for Mercury part numbers 46-96148A8 and 96148A8, and Sierra part number 18-3320.
- Includes all necessary components for a complete upper water pump housing repair.
- Engineered as a direct OEM-equivalent replacement for straightforward installation.
- Features a durable plastic housing designed to meet or exceed original specifications.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury |
46-96148A8 |
| Quicksilver |
96148A8 |
| Sierra |
18-3320 |
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
| Brand |
Model |
Rated HP |
Stroke |
Notes |
| Mercury/Mariner |
4-cylinder |
65-75 |
2-Stroke |
|
| Mercury/Mariner |
V6 |
75-220 |
2-Stroke |
Models with short-vane impellers |
MerCruiser Sterndrives
| Brand |
Model |
Notes |
| MerCruiser |
I Drive |
Serial No. 2491586-0D469858 |
| MerCruiser |
R Drive |
Serial No. 2491586-0D469858 |
| MerCruiser |
MR Drive |
Serial No. 2491586-0D469858 |
| MerCruiser |
Alpha Drive |
Serial No. 2491586-0D469858 |
Technical Specifications
| Specification |
Value |
| Product Type |
Water Pump Service Kit |
| Installation |
Direct OEM replacement |
| Housing Material |
Plastic |
| Housing Color |
Black |
| Weight |
0.60 lb (0.27 kg) |
| Other Technical Attributes |
Complete water pump repair kit for upper housing assembly |
Package Contents
- 1 x Plastic Pump Housing Assembly
- 1 x Water Impeller
- 1 x Face Plate
- 1 x Gasket Set
- 1 x Drive Key/Pin
- 1 x Water Tube Guide Sleeve
- 1 x "O" Ring Set
- 1 x Gearlube Fill & Vent Screw Seals
- 1 x Face Seal
- 1 x Seal Carrier
- 1 x Water Tube Coupling
Installation Guide
Professional installation is recommended. The general steps are outlined below:
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Disconnect the Battery: Ensure the engine is off and disconnect the battery terminals for safety.
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Remove Lower Unit: Unbolt and remove the sterndrive or outboard lower unit (gearcase) from the engine.
-
Access the Pump: Locate and remove the bolts securing the water pump housing. Slide the old housing assembly off the driveshaft.
-
Inspect & Clean: Remove the old impeller, key, gaskets, and wear plate. Clean all mating surfaces thoroughly, removing any old gasket material or corrosion.
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Install New Components: Place the new gaskets and wear plate. Install the new impeller drive key onto the shaft and slide the new impeller on, turning the shaft clockwise to bed the vanes correctly.
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Seat New Housing: Apply a light coat of marine grease to the inside of the new housing and install it over the impeller. Reinstall the housing bolts and tighten them to the manufacturer's specified torque.
-
Reassemble & Test: Reinstall the lower unit, ensuring the water tube aligns correctly with the pump outlet. Reconnect the battery, supply water to the engine using flushing muffs, and run it briefly to confirm proper water flow from the tell-tale outlet.
Troubleshooting & FAQ
- Q: How do I confirm this kit fits my specific engine?
- A: This kit fits MerCruiser I, R, MR, and Alpha sterndrives with serial numbers from 2491586 to 0D469858. It also fits Mercury/Mariner 65-220 HP 2-stroke outboards that use a short-vane impeller. Always verify using your engine's serial number and check against the part numbers listed.
- Q: What are the signs of a failing water pump?
- A: Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and in some cases, a steam-filled exhaust. A damaged impeller is the most common cause of failure.
- Q: How often should I replace the water pump impeller or service the kit?
- A: As a general rule, the impeller should be inspected annually and replaced every 1-2 years or every 100-200 hours of use, whichever comes first. This interval can be shorter if you operate in sandy, silty, or saltwater environments. Replacing the full kit is recommended for complete preventative maintenance.
- 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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.