How to Remove a Johnson Outboard Lower Unit

by Adam Paul

If you have an old Johnson outboard motor you will eventually need to replace the water pump or even the entire lower drive assembly. An outboard is made up of three primary components: a powerhead that houses the engine; an intermediary shaft that separates the powerhead from the lower unit; and the lower unit, the part of the motor that's submerged in the water with the propeller. Typically four bolts hold the lower unit to the intermediary shaft.

Open the outboard motor powerhead cover and locate the spark plugs on the rear of the engine. Disconnect the wires from the plugs by pulling them straight off to prevent accidental starting of the motor.

Place the outboard on a motor stand out of the water to allow access and a stable platform with which to work. Locate the four bolts holding on the lower unit, located near the place where the intermediary shaft and lower unit meet. There is no need to remove the propeller, as the entire assembly will be removed.

Remove the four attachment bolts from the lower housing by turning them counterclockwise with a wrench.

Gently tap the lower unit downward with a soft mallet until it separates from the powerhead. Once it separates, you may need to tilt the outboard motor upward to remove the lower unit and allow for the shaft to come out.


  • As a alternative to Step 1, run the motor out of fuel on the boat before removal, then remove the plug completely from the engine.

Items you will need


About the Author

Adam Paul has been writing professionally since 2007. His work has been featured in "BMW Owners News" and he also wrote a motorcycling column for SmartRemarx.com. Paul studied environmental science and journalism at the University of Maine and holds a Bachelor of Science in conservation law from Unity College.

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