Water Pump Repair Kit – Fits Mercury Marine 30–60 HP 4-Stroke Outboards
This water pump repair kit is designed for a wide range of Mercury Marine 30–60 HP 4-stroke outboard engines, including various EFI and carbureted models. It provides a reliable solution for maintaining your engine’s cooling system for optimal performance and longevity.
This kit serves as a direct replacement for Mercury part number 46-812966A12 and Sierra aftermarket part 18-3690, ensuring a precise fit and restoring original functionality.
- Includes all necessary components for a complete water pump overhaul.
- Engineered for a direct replacement of the OEM assembly for straightforward installation.
- Constructed with durable rubber and stainless steel components to withstand the marine environment.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury Marine |
46-812966A12 |
| Mercury Marine |
812966A12 |
| Sierra |
18-3690 |
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 |
Stroke |
Years |
OEM Part No. |
Notes |
| Mercury |
Outboard |
30 |
4-Stroke |
EFI 3 CYL |
46-812966A12 |
|
| Mercury |
Outboard |
35 |
4-Stroke |
EFI JET 4 CYL |
46-812966A12 |
|
| Mercury |
Outboard |
40 |
4-Stroke |
1999-2023 |
46-812966A12 |
Carb 4 Cylinder, EFI 3 CYL & 4 Cylinder models |
| Mercury |
Outboard |
40 |
4-Stroke |
EFI JET Seapro 4 CYL |
46-812966A12 |
|
| Mercury |
Outboard |
45 |
4-Stroke |
JET |
46-812966A12 |
|
| Mercury |
Outboard |
50 |
4-Stroke |
2001-2023 |
46-812966A12 |
EFI 3 CYL & 4 CYL models |
| Mercury |
Outboard |
55 |
4-Stroke |
3 CYL |
46-812966A12 |
|
| 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 Specifications
| Specification |
Value |
| 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 |
Package Contents
- 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 Guide
-
Safety First: Disconnect the engine's battery before starting any work.
-
Access the Lower Unit: Shift the outboard into neutral. Remove the bolts securing the lower unit (gearcase) to the engine's upper housing and carefully lower it.
-
Remove the Old Pump: Locate the water pump housing on top of the lower unit. Unbolt and remove the old housing to expose the impeller and wear plate.
-
Inspect and Clean: Remove the old impeller, key, gaskets, and plate. Thoroughly clean all mating surfaces, ensuring they are free of old gasket material and corrosion.
-
Install New Components: Place the new lower gasket and wear plate onto the lower unit. Slide the new impeller key into the driveshaft keyway and install the new impeller, turning the driveshaft clockwise to seat the vanes correctly.
-
Install New Housing: Place the upper gasket on the new housing. Install the new housing over the impeller and secure it with the bolts, tightening them to the manufacturer's specified torque.
-
Reassemble: Carefully guide the lower unit back into place, ensuring the driveshaft, shift shaft, and water tube align correctly. Reinstall the mounting bolts and tighten them securely.
-
Test Operation: Reconnect the battery. Start the engine in a water source (using a flusher or in the water) and confirm a steady stream of water from the tell-tale port.
Troubleshooting & FAQ
Q: How do I confirm this kit fits my specific Mercury engine?
A: Check your engine's model, horsepower, and year against the "Compatible Engine Models" table. For Mercury engines, it is highly recommended to verify the OEM part number (46-812966A12) required for your specific serial number. Use the provided Mercury serial number guide to help locate your engine's details.
Q: What are the signs my water pump is failing?
A: The most common signs include the engine overheating, a weak or intermittent water stream from the tell-tale (peephole) outlet, or discovering a brittle, cracked, or damaged impeller during a routine inspection.
Q: How often should I replace my outboard's water pump impeller?
A: As a critical preventative maintenance item, it is recommended to inspect the water pump and replace the impeller at least once a year or every 100-200 service hours, whichever comes first. This helps prevent unexpected overheating and engine damage.
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.