Water Pump Impeller Repair Kit – Fits Mercury/Mariner 30-70 HP (Replaces 46-77177A3, 77177A3)
Water Pump Impeller Repair Kit – Fits Mercury/Mariner 30-70 HP (Replaces 46-77177A3, 77177A3) 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 Impeller Repair Kit – Fits Mercury/Mariner 30-70 HP (Rep...
Water Pump Impeller Repair Kit – Fits Mercury/Mariner 30-70 HP (Replaces 46-77177A3, 77177A3) is backordered and will ship as soon as it is back in stock.
Product Details
This is a complete Water Pump Impeller Repair Kit – Fits Mercury/Mariner 30-70 HP (Replaces 46-77177A3, 77177A3), designed for various 2-stroke outboard engines from 1976–1997. The kit includes the impeller, housing, gaskets, and all necessary seals and hardware for a full service, ensuring your engine's cooling system functions reliably.
It serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 46-77177A3/77177A3, Sierra 18-3324, GLM 12100, Mallory 9-48312, and EMP 46-01115.
- Complete Assembly: Includes the plastic housing, neoprene impeller, and all required gaskets, seals, and o-rings for a comprehensive overhaul.
- Installation Location: Mounts in the lower unit (gearcase) of the outboard engine.
- Durable Materials: Features a housing made from high-strength Nylon PA66 plastic and a flexible neoprene rubber impeller for longevity and performance.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 46-77177A3 / 77177A3 |
| Sierra | 18-3324 |
| GLM | 12100 |
| Mallory | 9-48312 |
| EMP | 46-01115 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is designed for a wide range of Mercury and Mariner 2-stroke outboards. Please verify your engine's serial number against the ranges provided to ensure an exact match.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | JET (3CYL) | 30 | 2-Stroke | 1989–1997 | 46-77177A3 | Serial Range: 0C159200-0G589999, 9570790 & Up |
| Mercury/Mariner | Various | 35 | 2-Stroke | 1984–1989 | 46-77177A3 | 2 cylinders, Serial Range: 6445653 & Up, 209608 & Up |
| Mercury/Mariner | Various | 40 | 2-Stroke | 1978–1983 | 46-77177A3 | 2 cylinders, Serial Range: 5556230 & Up |
| Mercury | Various | 40 | 2-Stroke | 1989 & Up | 46-77177A3 | 4 cylinders, Serial Range: 0C159200 & Up, 9570790 & Up |
| Mercury | Various | 45 | 2-Stroke | 1986 & Up | 46-77177A3 | 4 cylinders, Serial Range: 5531630 & Up |
| Mercury | Various | 50 | 2-Stroke | 1978–1985 | 46-77177A3 | 4 cylinders, Serial Range: 4962056 & Up |
| Mercury | Various | 50 | 2-Stroke | 1984–1990 | 46-77177A3 | 3 cylinders, Serial Range: 6428681-0D000749, 0A721308 & Up |
| Mercury | Various | 60 | 2-Stroke | 1984–1990 | 46-77177A3 | 3 cylinders, Serial Range: 6428681-0D000749, 0A721308 & Up |
| Mercury | Various | 65 | 2-Stroke | 1976 | 46-77177A3 | 3 cylinders, Serial Range: 4382057-4571651 |
| Mercury | Various | 70 | 2-Stroke | 1977–1983 | 46-77177A3 | 3 cylinders, Serial Range: 4977157-0B110053, 5579017-6428680 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit with Housing
- Installation
- Lower Unit/Gearcase
- Housing Material
- Nylon PA66 Plastic
- Housing Color
- Black
- Impeller Material
- Neoprene Rubber
- Package Dimensions
- 156 × 102 × 53 mm (6.14 × 4.02 × 2.09 inches)
- Weight
- 0.22 kg (7.8 oz)
- Fitting Type
- Vehicle Specific Fit
- Warranty
- Lifetime (from some aftermarket suppliers)
What’s in the Box
- 1 x Water Pump Housing (77822A1)
- 1 x Insert (48753)
- 1 x Impeller (89983T)
- 1 x Upper Water Pump Gasket (19551)
- 1 x Lower Water Pump Gasket (19553)
- 1 x Face Plate (32768)
- 2 x Gasket (19552)
- 1 x O-Ring (25-26722)
- 2 x Drain Plug Seal (26-830749)
- 2 x O-Ring (805726)
- 1 x Key (8M0032837)
- 1 x Rubber (25-20273)
- 1 x Shift Bracket Seal (37721001)
Installation Notes
- Disconnect the battery's negative terminal before beginning work.
- Place a drain pan under the gearcase and remove the drain/fill screws to empty the gear oil.
- Remove the bolts securing the lower unit (gearcase) to the engine and carefully lower it.
- Unbolt and remove the old water pump housing assembly from the driveshaft.
- Thoroughly clean the mating surfaces where the new gaskets will sit.
- Assemble the new kit: install the key, new impeller (twist in the direction of engine rotation), face plate, and gaskets onto the driveshaft.
- Slide the new water pump housing over the impeller assembly and secure it with the bolts.
- Carefully guide the driveshaft and water tube into position while reinstalling the lower unit.
- Refill the gearcase with the correct type and amount of marine gear lubricant.
- Reconnect the battery. Start the engine using a water supply (flushing muffs) and verify a strong, steady stream from the "tell-tale" water outlet.
Troubleshooting & FAQ
How do I know if my water pump needs replacing?
Common signs of a failing water pump include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, or an impeller that is found to be brittle, cracked, or has missing vanes during a routine inspection.
What is the recommended replacement interval?
For optimal reliability and engine protection, it is recommended to inspect the impeller annually and replace the entire water pump kit every 2-3 years or 200-300 hours of operation. This interval should be shortened if the engine is operated frequently in sandy, silty, or saltwater conditions.
My old pump housing is metal. Why is this one plastic?
Modern aftermarket housings are often made from high-strength, corrosion-proof materials like Nylon PA66 plastic. These materials are engineered to meet or exceed the durability and performance standards of older metal housings, especially in saltwater environments where corrosion is a concern.
Why is a complete kit better than just replacing the impeller?
A complete kit is recommended because other components, such as the housing, wear plate, and seals, also degrade over time. A worn housing or bad seals can cause pressure loss and reduce cooling efficiency, even with a new impeller. Replacing the full assembly ensures all components are fresh for maximum reliability.
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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