Water Pump Impeller Repair Kit with Housing – Fits Johnson/Evinrude 25-50 HP (Replaces 438592)
Water Pump Impeller Repair Kit with Housing – Fits Johnson/Evinrude 25-50 HP (Replaces 438592) is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Repair Kit with Housing – Fits Johnson/Evinrude...
Water Pump Impeller Repair Kit with Housing – Fits Johnson/Evinrude 25-50 HP (Replaces 438592) is backordered and will ship as soon as it is back in stock.
Product Details
This complete Water Pump Impeller Repair Kit with Housing is designed for Johnson and Evinrude 2-stroke outboard engines. It provides a comprehensive solution for servicing the cooling system on compatible 25-50 HP engines, primarily targeting 40-50 HP two-cylinder models manufactured from 1989 to 2005. The kit also covers specific 25, 28, 30, and 35 HP jet drive units.
It serves as a direct replacement for Johnson/Evinrude OEM part number 438592 and Sierra aftermarket number 18-3454, among other cross-references, ensuring broad interchange compatibility.
- Installation Location: Lower Unit/Gearcase
- Key Component: Includes a three-vane neoprene impeller suitable for small gearcase configurations.
- Complete Kit: Contains the pump housing, impeller, wear plate, gaskets, seals, and stainless steel bolts for a full service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 0438592 / 438592 |
| Johnson/Evinrude | 433548 / 433549 / 777805 |
| Sierra | 18-3454 / 18-3394 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is verified for a range of Johnson and Evinrude 2-stroke models. Please check your specific horsepower, year, and application type (Gearcase or Jet Drive) to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Evinrude | 40 | 40 | 2-Stroke | 1997–1998 | 438592 | Gearcase |
| Evinrude | 50 | 50 | 2-Stroke | 1998 | 438592 | Gearcase |
| Johnson | 35 | 35 | 2-Stroke | 1997 | 438592 | Gearcase |
| Johnson | 40 | 40 | 2-Stroke | 1997–2005 | 438592 | Gearcase |
| Johnson | 50 | 50 | 2-Stroke | 1997–2001, 2004 | 438592 | Gearcase |
| Evinrude | 28 Jet | 28 | 2-Stroke | 1997–1998 | 438592 | Jet Drive Unit |
| Evinrude | 35 Jet | 35 | 2-Stroke | 1997 | 438592 | Jet Drive Unit |
| Evinrude | 40 Jet | 40 | 2-Stroke | 1997 | 438592 | Jet Drive Unit |
| Evinrude | 50 Jet | 50 | 2-Stroke | 1997 | 438592 | Jet Drive Unit |
| Johnson | 25 Jet | 25 | 2-Stroke | 2000 | 438592 | Jet Drive Unit |
| Johnson | 28 Jet | 28 | 2-Stroke | 1997–1998 | 438592 | Jet Drive Unit |
| Johnson | 30 Jet | 30 | 2-Stroke | 1999–2001 | 438592 | Jet Drive Unit |
| Johnson | 35 Jet | 35 | 2-Stroke | 1997 | 438592 | Jet Drive Unit |
| Johnson | 40 Jet | 40 | 2-Stroke | 1997 | 438592 | Jet Drive Unit |
| Johnson | 50 Jet | 50 | 2-Stroke | 1997 | 438592 | Jet Drive Unit |
| Johnson | 30 | 30 | 2-Stroke | 2001 | 438592 | Steering Handle |
Technical Specs
- Product Type
- Water Pump Repair Kit with Housing
- Installation
- Lower Unit/Gearcase
- Weight
- 0.51 kg (1.12 lbs)
- Other Technical Attributes
- For small gearcase configuration with three-vane impeller
- Warranty
- 12-Month (Varies by manufacturer)
What’s in the Box
- 1 x Neoprene Impeller, 3-vane (432941/437059/765350)
- 1 x Wear Plate (321940)
- 1 x Insert Cup/Water Pump Cup (340619)
- 1 x Water Pump Gasket (336530)
- 1 x Key/Impeller Key (334897)
- 1 x O-Ring (Possibly multiple)
- 1 x Water Seal/Oil Seal (315748)
- 1 x Pump Housing
- 1 x Grommet (333758)
- 4 x Installation Bolts, Stainless Steel (331979)
Installation Notes
- Disconnect the negative battery cable and remove the engine cover. Disconnect the shift linkage.
- Place a drain pan under the gearcase and remove the retaining bolts to lower the unit from the engine.
- Unbolt and carefully lift the old water pump housing. Note the orientation of the old impeller vanes.
- Remove the old impeller, key, wear plate, gaskets, and seals. Thoroughly clean all mounting surfaces.
- Install the new gasket and wear plate. Insert the new impeller key and slide the new impeller on, turning the driveshaft clockwise to seat the vanes correctly.
- Apply a thin layer of marine grease to the inside of the new insert cup and install it into the housing.
- Install the new gaskets/seals on the housing and secure it with the provided stainless steel bolts, tightening to manufacturer torque specs.
- Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are correctly aligned. Reconnect the shift linkage and test engine operation with a proper water supply.
Troubleshooting & FAQ
How do I confirm this kit fits my specific engine model?
First, check the compatibility table on this page to see if your model and year are listed. Second, verify that your engine's current part is an equivalent to OEM part number 438592. This kit is primarily for two-cylinder 40-50 HP models from 1989–2005 and specific jet drives.
What are the signs of a failing water pump impeller?
Common signs of a worn or failed impeller include the engine overheating at idle or low speeds, a weak or intermittent water stream from the "telltale" outlet, or finding brittle, cracked, or broken vanes during a visual inspection.
How often should the water pump impeller be replaced?
As a preventative maintenance best practice, it is recommended to inspect the impeller annually and replace it every 1 to 2 years, or every 100-200 hours of engine use. Replacement intervals should be shorter if operating frequently in saltwater, silty, or sandy conditions.
What is the main difference between this kit and an OEM version?
This kit is a high-quality aftermarket alternative, designed to meet or exceed original equipment specifications for fit, form, and function. It provides a cost-effective solution that includes all the necessary components for a complete water pump service, including the housing.
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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