Water Pump Repair Kit – Fits Mercury Outboards 65HP-V6 & MerCruiser Sterndrives (Replaces 96148A8)
This water pump repair kit provides the necessary components for servicing Mercury and Mariner 65HP (4-cylinder) through V6 outboard models that use short-vane impellers. It is also designed for MerCruiser I, R, MR, and Alpha One Gen 1 sterndrives within the serial number range of 2491586 to 0D469858.
This is a direct aftermarket replacement for Mercury/Quicksilver part number 96148A8, Sierra 18-3320, GLM 12120, and Mallory 9-48307.
- Engineered for direct-fit installation, replacing original OEM components without modification.
- Constructed with a plastic housing and a durable neoprene impeller to meet OEM specifications.
- This is a complete kit that includes the water pump base (46-44292A3).
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury/Quicksilver |
96148A8 |
| Sierra |
18-3320 |
| GLM |
12120 |
| Mallory |
9-48307 |
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.
| Brand |
Model |
Rated HP |
OEM Part No. |
Notes |
| Mercury/Mariner |
4-Cylinder Outboards |
65 |
96148A8 |
Short-vane impeller models only |
| Mercury/Mariner |
V6 Outboards |
75-225 |
96148A8 |
Short-vane impeller models only |
| MerCruiser |
I Drives |
- |
96148A8 |
Serial No. 2491586-0D469858 |
| MerCruiser |
R Drives |
- |
96148A8 |
Serial No. 2491586-0D469858 |
| MerCruiser |
MR Drives |
- |
96148A8 |
Serial No. 2491586-0D469858 |
| MerCruiser |
Alpha One Gen 1 |
- |
96148A8 |
Serial No. 2491586-0D469858 |
Technical Specifications
| Specification |
Value |
| Product Type |
Water Pump Repair Kit |
| Installation |
Direct replacement for OEM components |
| Housing Material |
Plastic (pump housing) |
| Impeller Material |
Neoprene |
| Housing Color |
Black |
| Fitting Type |
Direct fit to water pump base |
| Warranty |
30-day return/replacement (retailer warranty) |
| Base Diameter |
2.356 in (59.84 mm) |
Package Contents
- 1 x Water Pump Housing (46-96148A1)
- 1 x Impeller (47-89984)
- 1 x Impeller Plate (324351)
- 1 x Water Tube Guide (23-29804)
- 1 x Water Pump Housing Bushing (26-38970)
- 1 x Water Pump Base (46-44292A3)
- 1 x Water Pump Gasket (27-32438)
- 1 x Water Pump Base Gasket (27-33146)
- 1 x Water Pump Gasket (27-856081)
- 1 x Water Pump Gasket (27-858524)
- 1 x Water Pump Gasket (27-426311)
- 1 x Seal Ring Gasket (26-455771)
- 2 x Drain Screw Gasket (12-191833)
- 1 x O-Ring (25-30613)
- 1 x O-Ring (25-33145)
- 1 x O-Ring (25-30224)
- 1 x O-Ring (25-90011)
- 1 x O-Ring (25-30271)
- 1 x O-Ring (25-38099)
Installation Guide
- Disconnect the negative battery cable for safety.
- Unbolt and remove the lower unit (gearcase) from the outboard or sterndrive.
- Carefully remove the bolts securing the old water pump housing. Lift the housing off the driveshaft.
- Remove the old impeller, wear plate, gaskets, and other components included in the new kit.
-
CRITICAL FITMENT CHECK: Before installing, verify your engine's vertical shaft does NOT have a preload pin. This kit is only for shafts without this pin (typically MR or Alpha One Gen 1 drives). If a pin is present, you have an earlier R drive that requires a different kit.
- Clean all mounting surfaces thoroughly, ensuring they are free of old gasket material and corrosion.
- Install the new gaskets, wear plate, and impeller. Lubricate the inside of the new housing with a small amount of marine grease.
- Slide the new water pump assembly down over the driveshaft, ensuring the impeller key is properly aligned.
- Secure the housing with the mounting bolts, tightening them to the manufacturer's specified torque.
- Reinstall the lower unit, reconnect the battery, and test the engine's cooling system in water.
Troubleshooting & FAQ
How do I confirm this kit fits my MerCruiser drive?
First, check that your sterndrive's serial number falls between 2491586 and 0D469858. Second, perform the visual check mentioned in the installation guide: this kit is for driveshafts that DO NOT have a preload pin. If a pin is present on your shaft, this kit will not fit.
What is the main difference between this kit and others for MerCruiser?
This complete kit includes the plastic water pump base (part #46-44292A3) and is designed for models with a short-vane impeller. Some other kits may not include the base or may be for long-vane impellers. Be aware of your serial number; drives made around 1985-1986 can be confusing. Models with serial numbers before 6854393 are typically R drives and may require a different kit.
My engine is overheating at idle but not at speed. Could the impeller be the cause?
Yes, this is a classic symptom of a worn or damaged water pump impeller. A compromised impeller struggles to create sufficient water pressure at low RPMs, leading to overheating at idle or low speeds.
OEM vs. Aftermarket?
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.
How fast do you ship and how much does it cost?
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.
What is your warranty and return policy?
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.