How to replace a prop.

You’ve heard the phrase, “Weekends last longer when you carry a spare prop.” It’s true. There will come a time when you need to change your propeller while underway. Don’t let a prop get in the way of your boating fun. Here are some simple steps on replacing a prop on an alpha outboard engine.   Of course you can always contact our professional service advisors if you need help.


  1. Floating Prop Wrench

We like the Mercury Marine brand. After all, chances are your alpha outdrive is a Mercruiser, a Mercury built engine. Oh and Lake Union Sea Ray’s service departments will likely have some in-stock.

  1. Spare Propeller

Our Parts & Service departments can help you out here as well.

  1. Grease

We like Mercury’s 2-4-C Multi-Purpose Grease. Oh wait, our Parts & Service departments sell this product too. Did I mention that Lake Union Sea Ray is an authorized Mercury/MerCruiser dealer?

  1. Wood Block

You’re on your own here.


Tilt the outdrive up as far as possible. Pull the coil wire to disable the ignition. Bend the three tabs on the lock ring behind the nut so that they are straight and do not interfere with the removal of the nut.

Place a block of wood between the propeller blade and the cavitation plate, then remove the nut with the 1 1/16-inch wrench by turning the nut counterclockwise.

Remove the lock ring and the bronze drive sleeve. Remove the propeller and the thick bronze thrust washer behind it.

Lubricate the shaft with waterproof grease. Slide the thick bronze thrust washer, propeller, bronze drive sleeve and lock ring onto the shaft. Screw on the 1 1/16-inch nut.

Tighten the nut to 52 foot-pounds of torque. Bend the tabs on the lock ring behind the nut to prevent the nut from coming loose. Push the coil wire back on.