The water pump is the heart of your Mercury outboard's cooling system. It supplies a continuous flow of water through the powerhead to control operating temperature, protect internal engine components, and maintain reliable performance.
As the water pump housing, impeller, wear plate, and seals wear over time, cooling efficiency gradually decreases, increasing the risk of overheating and expensive powerhead damage.
The Buckshot Racing #77 Water Pump Housing Repair Kit is a complete service kit for many Mercury and Mariner 2.0L, 2.4L, and 2.5L V6 two-stroke outboards built from 1976 through 2005. It replaces Mercury OEM Water Pump Kit 46-96148A8, along with numerous earlier Mercury part numbers that have been superseded throughout production.
Designed for Mercury's Legendary V6 Engines
This kit fits many Mercury and Mariner V6 outboards, including 135 HP, 150 HP, 175 HP, and 200 HP carbureted, EFI, Laser EFI, XRi, Black Max, XR2, XR4, XR6, Pro Max, Offshore, and other V6 models using the standard V6 water pump assembly.
The same cooling system design was also used on numerous MerCruiser R, MR, Alpha One Gen I, and Alpha One Gen II sterndrives, making this kit suitable for many sterndrive applications as well. Always verify fitment by engine serial number before ordering.
Complete Water Pump Service Solution
Rather than replacing only the impeller, this kit provides the major service components needed to restore proper water pump performance during a lower unit service. It includes the water pump housing, impeller, guide tube, driveshaft key, water slinger, gaskets, O-rings, and sealing components required for a complete rebuild.
Replacing the complete housing assembly helps restore proper impeller clearance and pump efficiency while reducing the possibility of future cooling system failures caused by worn or grooved housings.
Replaces Numerous Mercury OEM Part Numbers
The Buckshot Racing #77 kit replaces Mercury OEM 46-96148A8, one of the most common water pump kits used on Mercury V6 outboards, while also replacing numerous earlier service numbers including 96148A5, 96148B5, 96148B8, 64141A11, 60367A1, 60367A4, 58618A4, 57234A1, 57234A3, 57234B1, 48747A3, 44292A4, 42579A4, 37433A1, 32437A1, 32437A3, 73802A3, 73804A3, 69222A3, 78400A2, 12120, and related Mercury service replacements.
Using these OEM cross-reference numbers makes it easier to identify the correct replacement kit when servicing older Mercury and Mariner outboards.
Why Routine Water Pump Service Is Important
Mercury recommends inspecting and servicing the water pump on a regular basis because the rubber impeller is considered a normal maintenance item. Heat, age, sand, silt, debris, and dry starts gradually reduce impeller efficiency. At the same time, the housing and wear surfaces develop grooves that reduce pump output.
A weak water pump can lead to low water pressure, reduced tell-tale flow, elevated engine temperatures, intermittent overheat alarms, poor cooling at idle, and, in severe cases, piston scuffing or complete powerhead failure.
Replacing the complete housing assembly instead of only the impeller restores the pump to like-new operating condition and helps maximize cooling performance.
Installation Recommendations
Whenever the lower unit is removed, inspect the water tube, guide tube seals, shift shaft seals, driveshaft seals, and water pump base for wear or corrosion. Lubricate the impeller during assembly, install the driveshaft key correctly, and rotate the driveshaft in the proper direction while lowering the housing over the impeller to correctly orient the vanes.
After installation, verify strong tell-tale flow, proper water pressure, and normal operating temperature before returning the engine to service.
Buckshot Racing #77 Tech Tip
For recreational engines, Mercury recommends replacing the water pump impeller approximately every 100 operating hours or every two to three years, whichever comes first. High-performance, saltwater, shallow-water, or racing applications should inspect the cooling system more frequently.
Replacing the complete 46-96148A8 water pump housing kit during scheduled maintenance provides inexpensive insurance against overheating and costly engine repairs.
Final Thoughts
The Buckshot Racing #77 Water Pump Housing Repair Kit is a complete replacement for Mercury OEM 46-96148A8 and numerous earlier Mercury water pump kits used on 2.0L, 2.4L, and 2.5L V6 Mercury and Mariner outboards.
Covering engines from 135 HP through 200 HP, along with many Black Max, XR2, XR4, XR6, Laser EFI, XRi, Pro Max, and compatible MerCruiser sterndrive applications, this complete service kit restores proper cooling system performance and helps protect your engine from overheating for years to come.
Contact Mike Hill with any tech questions at +1-714-697-1716 or mike@buckshotracing77.com