Water Pump Impeller Kit – Fits Mercury/Mariner & Johnson/Evinrude 30-70HP (Replaces 46-77177A3), Water Pump Impeller Kit – Fits Mercury/Mariner & Johnson/Evinrude 30-70HP (Replaces 46-77177A3)
Water Pump Impeller Kit – Fits Mercury/Mariner & Johnson/Evinrude 30-70HP (Replaces 46-77177A3), Water Pump Impeller Kit – Fits Mercury/Mariner & Johnson/Evinrude 30-70HP (Replaces 46-77177A3) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Impeller Kit – Fits Mercury/Mariner & Johnson/Evinru...
Product Details
This Water Pump Impeller Kit is designed to restore cooling performance in a wide range of Mercury/Mariner and Johnson/Evinrude 30–70HP 2-stroke outboard engines manufactured from the 1970s through the 1990s. It provides all necessary seals, gaskets, and the impeller to rebuild the water pump assembly, ensuring your engine maintains a safe operating temperature.
The kit serves as a direct replacement for Mercury/Mariner part number 46-77177A3 and BRP/Johnson/Evinrude part number 77177A3.
- Engineered for direct replacement without modifications.
- Kit contains the impeller, gaskets, seals, and plate needed for a standard rebuild.
- Please note: The water pump housing is not included in this kit.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury / Mariner | 46-77177A3 | Water pump repair kit without housing |
| BRP / Johnson / Evinrude | 77177A3 | Water pump repair kit without housing |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is confirmed to fit various 2-stroke outboards from Mercury, Mariner, Johnson, and Evinrude within the specified horsepower range and years.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury/Mariner | Various | 30–70 | 2-Stroke | 1974–1990s | 46-77177A3 | Water pump repair kit without housing |
| Johnson/Evinrude | Various | 30–70 | 2-Stroke | 1974–1990s | 77177A3 | Water pump repair kit without housing |
Technical Specs
- Product Type
- Water Pump Impeller Kit (without housing)
- Installation
- Direct replacement
- Other Technical Attributes
- Kit does not include pump housing
What’s in the Box
- 1 x Water Pump Impeller
- 1 x Gaskets
- 1 x Drive Key
- 1 x Face Plate
- 1 x Face Seal
- 1 x Seal Carrier
- 1 x Water Tube Coupling
Installation Notes
- Disconnect the battery and remove the propeller for safety.
- Place a drain pan under the lower unit and remove the drain/fill screws to drain the gearcase oil.
- Unbolt and carefully lower the gearcase (lower unit) from the engine's midsection.
- Locate the water pump housing on top of the gearcase. Remove the bolts securing it.
- Lift the housing off and slide the old impeller off the driveshaft. Note the rotational direction of the old impeller vanes.
- Clean the housing interior, face plate, and base. Inspect the housing for melting, scoring, or cracks.
- Install the new gaskets, seals, and face plate from the kit.
- Slide the new drive key and impeller onto the driveshaft. Lubricate and install the new impeller, twisting it in the direction of engine rotation to seat the vanes correctly.
- Reinstall the water pump housing and torque its bolts to the manufacturer's specification.
- Raise the gearcase back into position, ensuring the driveshaft, shift shaft, and water tube align correctly. Bolt it securely.
- Refill the gearcase with fresh marine gear lube. Reinstall the propeller.
- Reconnect the battery and test the engine using a water source ("muffs" or in the water). Check for a steady stream of water from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if my water pump impeller is failing?
Common signs include a weak or nonexistent water stream from the "tell-tale" outlet, engine overheating alarms, or a visible reduction in water pressure. It is a critical maintenance item that should be inspected regularly and replaced proactively.
Does this impeller kit include the pump housing?
No, this is a repair kit that does not include the metal or plastic pump housing. This kit is intended for situations where your existing housing is still in good condition and only the internal components (impeller, gaskets, seals) need replacement.
How often should I replace my water pump impeller?
For most recreational boaters, it is recommended to replace the impeller every 1-2 years. If you operate in sandy, silty, or saltwater conditions, annual replacement is strongly advised to prevent unexpected failure.
My engine overheated. Will replacing the impeller fix it?
A failed impeller is a very common cause of overheating. Replacing it often solves the problem, but overheating can also be caused by thermostat issues, blockages in cooling passages, or a damaged pump housing. If a new impeller doesn't fix the issue, further diagnostics are required.
Is this kit compatible with my specific engine model and year?
This kit fits a broad range of Mercury/Mariner and Johnson/Evinrude 30–70HP 2-stroke outboards from the 1970s–1990s. Always verify your OEM part number against those listed (46-77177A3 or 77177A3) and check the engine compatibility table. If unsure, consult your service manual or a qualified marine mechanic.
What’s the difference between this impeller and the original OEM one?
While this is an aftermarket kit, it is manufactured to meet or exceed original equipment specifications for fit, materials, and performance. The primary difference is that it offers a comparable-quality solution at a more accessible price point.
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.
Payment & Security
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