Water Pump Repair Kit – Fits Mercury Marine 30-60 HP 4-Stroke Outboards (Replaces 46-812966A12, 812966A12)
Water Pump Repair Kit – Fits Mercury Marine 30-60 HP 4-Stroke Outboards (Replaces 46-812966A12, 812966A12) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Water Pump Repair Kit – Fits Mercury Marine 30-60 HP 4-Stroke Outbo...
Water Pump Repair Kit – Fits Mercury Marine 30-60 HP 4-Stroke Outboards (Replaces 46-812966A12, 812966A12) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Repair Kit – Fits Mercury Marine 30–60 HP 4-Stroke Outboards is designed for comprehensive maintenance and repair of your engine's cooling system. It is engineered for a wide range of Mercury Outboards from 30 to 60 HP, including various EFI, carbureted, and Jet models manufactured between 1999 and 2023.
The kit serves as a direct replacement for Mercury OEM part numbers 46-812966A12 and 812966A12, and interchanges with Sierra Marine part 18-3690.
- Installs as a direct replacement for original factory parts.
- Constructed with durable rubber and stainless steel components to resist corrosion in marine environments.
- Includes all essential components: impeller, housing, base, plate, gaskets, and hardware for a complete overhaul.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 46-812966A12 |
| Mercury | 812966A12 |
| Sierra | 18-3690 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | Outboard | 30 | 4-Stroke | 46-812966A12 | EFI 3 CYL | |
| Mercury | Outboard | 35 | 4-Stroke | 46-812966A12 | EFI JET 4 CYL | |
| Mercury | Outboard | 40 | 4-Stroke | 1999–2023 | 46-812966A12 | Carb 4 Cylinder, EFI 3 CYL & 4 Cylinder models |
| Mercury | Outboard | 40 | 4-Stroke | 46-812966A12 | EFI JET Seapro 4 CYL | |
| Mercury | Outboard | 45 | 4-Stroke | 46-812966A12 | JET | |
| Mercury | Outboard | 50 | 4-Stroke | 2001–2023 | 46-812966A12 | EFI 3 CYL & 4 CYL models |
| Mercury | Outboard | 55 | 4-Stroke | 46-812966A12 | 3 CYL | |
| Mercury | Outboard | 60 | 4-Stroke | 2001–2023 | 46-812966A12 | EFI seapro 3 CYL & 4 CYL models, Bigfoot (s/n 0G760300-0T979999) |
| Formula | Outboard | 60 | 4-Stroke | S/N 1C104574 & UP | 46-812966A12 |
Technical Specs
- Product Type
- Water Pump Repair Kit
- Installation
- Direct replacement for Mercury Marine outboards
- Housing Material
- Rubber, Stainless Steel components
- Weight
- 0.64 kg (1.4 lb)
- Warranty
- Manufacturer warranty (varies by brand)
- Other Technical Attributes
- Complete kit includes impeller, housing, gaskets, and all necessary hardware
What’s in the Box
- 1 x Water Pump Impeller (47-19453T)
- 1 x Impeller Key
- 1 x Plate (19700A 2)
- 1 x Housing (14334A 3)
- 1 x Water Pump Base (46-812966A 7)
- 1 x Guide Tube (859770)
- 2 x Washer (12-858234)
- 1 x Gasket Upper (27-822189)
- 1 x Gasket Lower (27-19701)
- 1 x O-Ring
Installation Notes
- Disconnect the battery and ensure the engine is turned off and cool.
- Place a suitable container under the lower unit to catch any residual fluids.
- Unbolt and carefully lower the gearcase/lower unit from the outboard's driveshaft housing.
- Remove the old water pump housing, impeller, gaskets, and wear plate. Clean all mating surfaces thoroughly.
- Install the new components from the kit in the reverse order of removal. Ensure the impeller key is correctly seated.
- Apply a small amount of marine grease to the interior of the new housing and impeller.
- Rotate the driveshaft clockwise while sliding the new housing down over the impeller to set the vanes correctly.
- Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are properly aligned.
- Tighten all bolts to the manufacturer's specified torque. Reconnect the battery.
- Start the engine in water and verify a steady stream of water is exiting the tell-tale port.
Troubleshooting & FAQ
How do I know if this kit fits my specific engine model?
This kit is designed for a broad range of Mercury 30-60 HP 4-stroke outboards. The best way to ensure a match is to compare your engine's OEM part number to 46-812966A12, 812966A12, or Sierra 18-3690. Refer to the compatibility table and check any listed serial number ranges or notes.
What are the signs of a failing water pump?
Common signs include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, and in severe cases, steam from the exhaust. Reduced engine performance can also indicate a cooling problem.
How often should the water pump impeller be replaced?
As a general maintenance guideline, mechanics recommend replacing the water pump impeller every 100-200 service hours or annually, whichever comes first. This interval can be shorter if the boat is operated in sandy, silty, or saltwater environments.
Is the housing included in this kit?
Yes, this is a complete repair kit that includes the water pump housing (14334A 3), base (46-812966A 7), and wear plate (19700A 2), in addition to the impeller and all necessary gaskets, o-rings, and hardware.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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