Water Pump Impeller Kit with Housing – Fits Mercury/Mariner 30-70 HP (Replaces 46-77177A3, Sierra 18-3324)
Water Pump Impeller Kit with Housing – Fits Mercury/Mariner 30-70 HP (Replaces 46-77177A3, Sierra 18-3324) is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Kit with Housing – Fits Mercury/Mariner 30-70 H...
Water Pump Impeller Kit with Housing – Fits Mercury/Mariner 30-70 HP (Replaces 46-77177A3, Sierra 18-3324) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit with Housing is an essential service part for Mercury/Mariner 2-stroke outboard engines ranging from 30 to 70 HP, covering models from 1977 to 1997.
It serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 46-77177A3, Quicksilver 77177A3, Sierra 18-3324, GLM 12100, and Mallory 9-48312.
- Installation: Direct-fit replacement for the original assembly.
- Core Components: Includes a neoprene rubber impeller, stainless steel wear plate, and a complete upper and lower pump housing.
- Durability: Designed with corrosion-resistant materials for reliable performance in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 46-77177A3 |
| Quicksilver | 77177A3 |
| Sierra | 18-3324 |
| GLM | 12100 |
| Mallory | 9-48312 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | JET | 30 | 2-Stroke | 1989–1997 | 46-77177A3 | USA 0C159200-0G589999 |
| Mercury/Mariner | - | 35 | 2-Stroke | 1984–1989 | 46-77177A3 | 2 cylinder |
| Mercury/Mariner | - | 40 | 2-Stroke | 1978–1983 | 46-77177A3 | USA 4860103 thru MY1983, AUS 8052125 & above, BEL 9184451 thru MY1983, CAN 7112423 & above |
| Mercury/Mariner | - | 40 | 2-Stroke | 1989 and up | 46-77177A3 | 4 cylinder |
| Mercury/Mariner | - | 45 | 2-Stroke | 1986 and up | 46-77177A3 | 4 cylinder |
| Mercury/Mariner | - | 50 | 2-Stroke | 1978–1985 | 46-77177A3 | 4 cylinder; USA 5531630 & above, AUS 8063985 & above, BEL 9248006 & above, CAN 7143688 & above |
| Mercury/Mariner | - | 50 | 2-Stroke | 1984–1990 | 46-77177A3 | 3 cylinder; USA 6428681-0D000749, BEL 9385911-9683054, CAN 7208333 & above |
| Mercury/Mariner | - | 60 | 2-Stroke | 1984–1990 | 46-77177A3 | 3 cylinder; USA 6428681-0D000749, BEL 9385911-9683054, CAN 7208333 & above |
| Mercury/Mariner | - | 65 | 2-Stroke | 1976 | 46-77177A3 | 3 cylinder |
| Mercury/Mariner | - | 70 | 2-Stroke | 1977–1983 | 46-77177A3 | 3 cylinder; USA 4977157-6428680, AUS 8050200 & above, BEL 9196961-9385910, CAN 7110998-7208332 |
| Mercury | Mariner Magnum | 40 | 2-Stroke | Up to 1996 | 46-77177A3 | Verified fit by customer review |
Technical Specs
- Product Type
- Water Pump Repair Kit with Housing
- Installation
- Direct replacement
- Material
- Neoprene rubber (impeller), stainless steel, plastic
- Housing Material
- Plastic, metal
- Dimensions
- 108 × 108 × 51 mm (4.25 × 4.25 × 2.0 in)
- Weight
- 0.34 kg (0.75 lb)
- Warranty
- Lifetime (from some aftermarket suppliers)
- Other Technical Attributes
- Includes complete water pump assembly with upper and lower housings
What’s in the Box
- 1 x Water Pump Impeller
- 1 x Impeller Plate
- 1 x Impeller Key
- 1 x Water Pump Housing
- 1 x Water Pump Base
- 1 x Water Pump Base Gasket
- 1 x Lower Gasket
- 1 x Upper Gasket
- 1 x Drain Screw Gasket
- 1 x Rubber Washer
- 1 x O-Ring
- 1 x Water Tube Coupling (included in some kits)
Installation Notes
- Disconnect the battery and uncouple the shift linkage.
- Remove the lower unit (gearcase) mounting bolts and carefully lower the unit from the outboard leg.
- Unbolt and remove the old water pump assembly from the top of the lower unit. Note the orientation of all parts.
- Thoroughly clean the driveshaft and mating surfaces where the pump housing sits.
- Install the new lower gasket, wear plate, and impeller key. Slide the new impeller onto the driveshaft, turning the shaft clockwise to bed the vanes.
- Lightly lubricate the inside of the new housing and slide it down over the impeller.
- Secure the new housing with its bolts, tightening them to the manufacturer's recommended torque specification.
- Reinstall the lower unit, carefully aligning the driveshaft, shift shaft, and water tube. Reconnect all linkages.
- Once assembled, test the engine using a flush-muff or in the water to confirm a strong telltale stream and proper cooling.
Troubleshooting & FAQ
How do I know if this kit fits my specific engine model?
This kit is designed for a wide range of Mercury and Mariner 2-stroke outboards from 30–70 HP (1977–1997). To confirm fitment, please consult the detailed Engine & Model Compatibility table on this page and verify your engine's model year or serial number range.
What are the signs of a failing water pump impeller?
Common signs of a worn or damaged impeller include the engine overheating at idle or low speeds, a weak or non-existent stream of water from the "telltale" indicator, and a burnt rubber smell. Upon inspection, the old impeller may appear brittle, cracked, or have missing vanes.
How often should the water pump be serviced?
For preventative maintenance, it is recommended to inspect and/or replace the water pump impeller every 1-2 years or every 100-200 hours of operation. Service intervals may be shorter in saltwater or silty/sandy conditions.
Is the housing included in this kit?
Yes, this is a complete water pump service kit that includes both the upper and lower housings, the impeller, a new wear plate, and all necessary gaskets, o-rings, and hardware for a full replacement.
My old part is stamped 46-77177A3. Is this the right kit?
Yes, this kit is a direct aftermarket replacement for Mercury OEM part number 46-77177A3. It also cross-references with several other part numbers listed in our Part Number Matrix.
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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