how to change a prop on mercruiser alpha one outdrive 4.3L 2010 bayliner BR 195

jim casparis

Cadet
Joined
Oct 10, 2021
Messages
8
Thank you. The nut is really tight. It's 1 1/16th " and my wrench hasn't been able to break it free. I stuck a long 3/8 extension bar down between the prop & outdrive to obtain some leverage but it still won't break loose. I'm afraid too much force will break something on the outdrive. Will it?
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
12,687
try penetrating oil like Kroil or Freeze off, spray on and let it sit. The prop should be remvoed once a year and the shaft and nut threads greased so that doesn't happen. I've never had trouble getting mine off and this boat sits in salt water all season.
 

alldodge

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Mar 8, 2009
Messages
42,067
I would use a short piece of 2x4 between ventilation plate and prop to hold.
 

jim casparis

Cadet
Joined
Oct 10, 2021
Messages
8
Thanks, I've sprayed it - now waiting for it to work. Just bought this boat yesterday, and I don't think the prop's ever been removed. But it will be from now on!
 

Lou C

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Nov 10, 2002
Messages
12,687
I have a piece of scrap wood I keep in the boat just for that.
 

Lou C

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Nov 10, 2002
Messages
12,687
if you have an electric impact gun that might work as well. Make sure the outdrive is in neutral, and you have something to keep the prop from turning as I mentioned above.
 

Chris1956

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Joined
Mar 25, 2004
Messages
27,854
The nut is usually easy to remove. You have bent all 3 of the "legs" of the spider washer toward the rear of the boat to allow the nut to turn, right? A large screwdriver usually works for this.

A 2X4 from the zinc fin behind the prop to the "neck" of the outdrive will jam the prop safely, to allow you to loosen the prop nut.

After the nut is off, the spider washer is next, followed by the fitting that locks the spider's legs (this can be part of the prop or separate), then the prop itself, and lastly, the thrust hub.

Realistically, the prop will be the hardest to remove. Use a 2X4 to gently pry against the prop blades, one at a time, to work it off.

Post back when you get to this stage.
 

Lou C

Supreme Mariner
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Nov 10, 2002
Messages
12,687
evinrude triple guard grease on the splines and threads.
 
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