GHmarine Impeller Repair Kit for Johnson & Evinrude 4–8 HP Outboards — 396644 OEM-Equivalent with Gaskets & Seals

GHmarine 396644 is a complete impeller repair kit engineered to restore cooling flow on Johnson and Evinrude 4–8 HP outboard engines.

Whether you’re doing seasonal maintenance or fixing a failing water pump, this kit contains the parts to replace the impeller and its associated seals and gaskets for a reliable cooling system. Built to match OEM fit and function, the set replaces Johnson/Evinrude part numbers 396644, 389844, 765603 and Sierra 18-4529, and fits a broad range of small outboards from 4 to 8 horsepower across multiple production years.

Which engines will this impeller kit fit?

This GHmarine kit is designed for compatibility with many Johnson and Evinrude small outboards. It covers multiple model years and horsepower ratings so you can match it to older or newer motors without guessing.

• 4 HP: models from 1986–1992
• 4.5 HP: models from 1980–1984
• 5 HP: models from 1980–1983 and 1996–2001
• 6 HP: models from 1984–2001 and 2003–2005
• 8 HP: models from 1980–2001 and 2003–2005

What parts are included in the kit and why they matter?

This repair kit bundles the impeller with the gaskets, O-rings and seals needed to reseal the water pump housing and restore proper circulation. Replacing the entire assembly prevents leaks and uneven wear that can happen when only the impeller is changed.

• Rubber impeller — moves cooling water across the engine’s lower unit
• Gaskets and O-rings — ensure a watertight seal for consistent pressure
• Seals and hardware — replace worn components that cause leaks or vibration
• OEM-equivalent fitments — matches Johnson/Evinrude part numbers for straightforward installation

How will installing this kit affect my engine’s performance?

Replacing a worn impeller and seals restores proper cooling flow, reducing the risk of overheating and maintaining the engine’s designed operating temperature. While it won’t change engine power, it protects internal components and supports reliable operation on the water.

• Improves coolant circulation through the exhaust and water jackets
• Reduces chances of heat-related wear to the lower unit and cylinder head
• Prevents cavitation and irregular water flow from cracked or missing vanes
• Stops leaks that can lead to reduced pump efficiency

Is this kit easy to install and what tools will I need?

For a mechanically inclined boater, installation is straightforward with basic hand tools and a few specialty items depending on your engine. The kit’s components are sized for direct replacement, which simplifies the process compared with sourcing parts individually.

• Basic set: screwdrivers, socket set, pliers
• Helpful extras: impeller puller (if needed), seal lubricant, torque wrench
• Time estimate: typically 45–90 minutes for routine replacement
• Manual reference: consult your engine service manual for torque specs and alignment

Who is this for: GHmarine’s 396644 impeller kit is intended for owners, mechanics, and marina technicians maintaining Johnson and Evinrude 4–8 HP outboards who want a single, OEM-equivalent package to complete water pump service. It’s well suited to seasonal tune-ups, preventative maintenance schedules, and field repairs where restoring proper cooling quickly is essential. If you operate older small outboards or keep spare parts on board, this kit gives you the gaskets and seals needed to finish the job without multiple parts orders.