Water Pump Impeller Kit – Fits Johnson/Evinrude 25–50 HP (Replaces 432941, 766433, 777825)
Water Pump Impeller Kit – Fits Johnson/Evinrude 25–50 HP (Replaces 432941, 766433, 777825) 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 Kit – Fits Johnson/Evinrude 25–50 HP (Replaces ...
Water Pump Impeller Kit – Fits Johnson/Evinrude 25–50 HP (Replaces 432941, 766433, 777825) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit is designed for Johnson and Evinrude 25 HP to 50 HP 2-stroke outboards from 1989 to 1998. Compatible models include 35 HP Jet (1992–1993), 40 HP (1989–1998), 48 HP (1989–1996), and 50 HP (1989–1998) engines.
It serves as a direct replacement for Johnson/Evinrude part numbers 432941, 0432941, 765350, 0765350, 437059, 0437059, 766433, 0766435, 777825, and 0777825, as well as Sierra part 18-3104.
- Installs in the lower unit/gear case to restore engine cooling performance.
- Made from marine-grade CR neoprene rubber with a hardened nylon hub for durability.
- Kit includes the essential impeller, drive shaft key, and gasket for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 432941 / 0432941 |
| Johnson/Evinrude | 765350 / 0765350 |
| Johnson/Evinrude | 437059 / 0437059 |
| Johnson/Evinrude | 766433 / 0766435 |
| Johnson/Evinrude | 777825 / 0777825 |
| Sierra | 18-3104 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Fits a range of Johnson and Evinrude outboards. Please verify your OEM part number before ordering.
| Brand | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|
| Evinrude/Johnson | 35 HP Jet | 2-Stroke | 1992–1993 | 432941 |
| Evinrude/Johnson | 40 HP | 2-Stroke | 1989–1998 | 432941 |
| Evinrude/Johnson | 48 HP | 2-Stroke | 1989–1996 | 432941 |
| Evinrude/Johnson | 50 HP | 2-Stroke | 1989–1998 | 432941 |
Technical Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Lower Unit/Gear Case
- Material
- Neoprene Rubber (Impeller)
- Dimensions
- 91.3 mm diameter × 25.4 mm height (3.59 in × 1.00 in)
- Hub Shaft Diameter
- 19.1 mm (0.75 in)
- Number of Blades
- 6
- Weight
- 68 g (2.4 oz)
- Color
- Black
- Other Technical Attributes
- Marine Grade CR Neoprene Rubber Impeller with Hardened Nylon Hub
What’s in the Box
- 1 × Rubber Impeller
- 1 × Drive Shaft Key
- 1 × Gasket
Installation Notes
- Disconnect the battery and shift the outboard into neutral.
- Remove the bolts securing the lower unit (gear case) to the engine housing.
- Carefully lower and separate the gear case from the driveshaft housing.
- Locate the water pump housing on the gear case and remove its mounting bolts.
- Slide the housing up to expose the old impeller. Remove the impeller, woodruff key, and old gasket.
- Thoroughly clean the housing interior and base plate surfaces.
- Install the new drive shaft key and slide the new impeller on, rotating the driveshaft clockwise to seat the blades.
- Place the new gasket on the clean base plate.
- Reinstall the water pump housing and tighten its bolts to the manufacturer's torque specification.
- Re-install the lower unit, ensuring the driveshaft and water tube align correctly, and secure the bolts.
Troubleshooting & FAQ
How often should I replace my water pump impeller?
For most recreational boaters, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of use, whichever comes first. Frequent use in saltwater or sandy/silty conditions may require more frequent replacement.
What are the signs of a failing impeller?
Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent stream of water from the "tell-tale" outlet, or finding brittle, cracked, or broken rubber pieces in the cooling system upon inspection.
My engine model falls within the year range, how can I be sure this fits?
The best way to ensure compatibility is to match your existing part number to one of the cross-reference numbers listed (e.g., 432941, 777825). If you cannot find a part number, visually compare your old impeller's dimensions and hub design to the specifications and photos provided here.
Why do some sources show different compatible year ranges?
Manufacturers sometimes make mid-year changes or use leftover parts across model years. Our data is aggregated from multiple sources to provide the most comprehensive range, but you should always prioritize matching the OEM part number from your specific engine's service manual or existing part.
Is this impeller difficult to install?
Installation is a common maintenance task for those with mechanical experience and the correct tools. It involves removing the lower unit. If you are not comfortable with this process, we recommend hiring a qualified marine mechanic to ensure it's done correctly.
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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