GHmarine Water Pump Impeller Repair Kit for Johnson/Evinrude 40–50 HP — Replaces 438592 with Housing & Seals

GHmarine's water pump impeller repair kit is a complete OEM-spec replacement set designed to restore cooling to Evinrude/Johnson 40–50 HP 2-cylinder outboards by replacing part 438592 and compatible OEM numbers.

Whether you maintain an older 40–50 HP Johnson or Evinrude two-stroke or are preparing your boat for the season, this repair kit supplies the parts needed to rebuild the water pump housing and impeller assembly. It replaces multiple factory part numbers (433548, 433549, 438592, 777805 and equivalents) and fits many models from roughly 1986 through 2005. The kit bundles the impeller, housing, seals and hardware so you can complete the job in one service session.

How does this kit restore cooling to a 40–50 HP outboard?

The kit contains the core wear and sealing components that move raw water through the engine’s cooling passages. Installing the new impeller and housing re-establishes proper water flow and pressure when the engine is running.

• Includes molded rubber impeller and impeller key to ensure correct fit and rotation.
• New water pump housing and cup replace corroded or cracked parts that leak or cavitate.
• Seals, o-rings and gasket restore a watertight assembly to prevent bypass and loss of pressure.
• Stainless steel bolts resist corrosion for longer service life.

Which engine models and OEM numbers does this GHmarine kit match?

This rebuild kit is made for two-cylinder, two-stroke Johnson and Evinrude outboards in the 40–50 HP range, commonly found on models produced from about 1986 to 2005. It is engineered to replace several factory part numbers to simplify sourcing.

• Direct replacement for OEMs: 433548, 433549, 438592, 777805 (and related formats).
• Compatible with aftermarket cross-references such as Sierra 18-3454 and 18-3394, Mallory 9-48209.
• Designed for most 2-cylinder 40, 45, 48 and 50 HP Johnson/Evinrude engines of the era.

What components are included and what should I inspect while rebuilding?

The kit is comprehensive so you rarely need extra parts for a standard impeller rebuild. While you have the pump apart, check neighboring components for wear or corrosion to avoid repeat service.

• Kit contents: 1 impeller, 1 impeller key, 1 wear plate, 1 gasket, 1 oil seal, 1 shaft seal, 1 grommet, pump housing and cup, 4 stainless bolts and 2 o-rings.
• Inspect the driveshaft and keyway for scoring and the thermostat housing for blockage or corrosion.
• Verify water pickup screens and hoses are clear to ensure full flow after assembly.

How often should I replace the impeller and when is replacement urgent?

Marine impellers are wear items that should be checked every season and generally replaced every two to three seasons depending on use and water quality. Replace immediately if you notice overheating, reduced temperature regulation or visible damage to the old impeller.

• Check the impeller for torn blades, hardening or missing segments each spring.
• Replace sooner if running in sandy, silty, or heavily mineralized water.
• A seized, shredded, or collapsed impeller demands immediate replacement to avoid engine damage.

Who is this for: The GHmarine 438592 water pump impeller repair kit is aimed at boat owners, DIY marine mechanics and professional service shops working on 2-cylinder Johnson and Evinrude 40–50 HP outboards from the late 1980s through the early 2000s. If you need a full rebuild pack that matches common OEM part numbers and includes the housing, seals and hardware, this kit offers a practical, service-ready solution to bring an older outboard’s cooling system back to reliable operation.