How do you change a propeller on a boat? Well it is a lot easier than most people think. If you can change a tyre on your car, you can change a propeller on your boat, it's simply that most people simply haven’t done it before. As Lenny Rudow shows in his simple guide and video below, it's an ideal DIY project that can save you a few pennies. (If you need a new propeller, read our guide to Boat propellers)

Ready to get started? Read on, and watch our How to Change a Boat Propeller video.


Step by step guide to changing a propeller

Here’s a step-by-step run-down on how to get that old prop off, and put a new one on.

Top tip: as you remove each part place it in a safe place, lined up with the other parts, in order or removal. That way, you’ll know the order each part goes back on.

Step 1: Block the prop, so it doesn’t spin as you apply pressure to the prop nut.

Step 2: Straighten and remove the cotter pin, using a pair of pliers (some props will have a circular tab, instead of a cotter pin).

Change a propeller: straighten and remove the cotter pin.

Straighten the cotter pin.

Step 3: Remove the prop nut with a ratchet, or a prop-puller (a wrench designed just for prop nuts).

Step 4: Slide off all washers and spacers. Remember: keep these in order, and lined up so you know what goes back on when, and in which direction.

Step 5: Slide off the prop itself.

Step 6: Before you put on the new prop, clean the spline and give it a fresh coat of grease.

Putting on the new propeller is simply a matter of following the above steps, in reverse. All finished? Good job. Now get yourself a drink to celebrate - you’re ready to go boating again.

Change a propeller; putting the new propeller on

Putting the new propeller on.


Written by: Lenny Rudow
With over two decades of experience in marine journalism, Lenny Rudow has contributed to publications including YachtWorld,, Boating Magazine, Marlin Magazine, Boating World, Saltwater Sportsman, Texas Fish & Game, and many others. Lenny is a graduate of the Westlawn School of Yacht Design, and he has won numerous BWI and OWAA writing awards.