Mercury propeller

Someone knows how to change the propeller of a Mercury 20Hp and what tools is needed.
Thank you

 

Prop changes are quite simple and require very basic tools and understanding. Have you a manual for this engine? This is the first "tool" you purchase for an engine of any type. You'll need a wrench, screw driver, maybe a pair of pliers and a small, light weight deadblow mallet. Just looking at it, you should see a cotter pin or nut with a sheet metal washer, folded up around the nut flats. This should make removal apparent, if not - do yourself a big favor and look up "outboard prop removal" on YouTube, as dozens of videos will show you in 5 minutes or less. Simply put, if removing the prop requires asking, you really need a manual bad.

 

Thank you PAR for telling me I am the king of the imbecile.
But I should have been more specific in my question, and you more specific in your answer: what size of tool wrench?
That will have been more helpful than a long tirade about....nothing.
Please keep your so call knowledge for yourself since you don't know the answer obviously.
Thank you

 

Most look at a nut, then grab a few wrenches in the general size range, hoping they've guessed right. Maybe an adjustable wrench? It's a nut, a keeper of some sort and you're done. Literally looking at the business end of the lower leg, should explain all, if not a manual or 5 minute video will hand hold you through the process. I'm not trying to be curt, but this is about as simple as it gets - a single nut and it's keeper. If you have a keeper washer, pounding the tabs flat might take a couple of minutes. If it's a cotter pin, just cut it off with a set of dikes and pull out the pieces. A block of wood to keep the prop from turning is a good idea, though most figure this out once they realize it's turning with the wrench. 1 1/16" is the usual size.

http://youtu.be/XvmoqsYs0ZM
http://youtu.be/JcuYo0HvczM
http://youtu.be/wAjZdEe8V8c

 

Thank you PAR, much appreciated.
After all I was wrong, you know a lot!
I was just frustrated to don't find anything about the size, the manual is no use, it is a pathetic booklet with stupids drawings.
Internet is full of seller, but no informations.
Thanks again, sorry for the outburst

 

You're allowed to get pissed, I sure do from time to time. Some manuals are better then others, have a look around for a different one.

Getting nut sizes displayed in these books isn't as common as you'd think, mostly because they often cover different models and years of outboards, which might have different and varying fasteners sizes.

 

My 1972 Merc 20 has a 7/16-20 TPI Right Hand Thread self locking nut. The socket size is 5/8" Anyone who owns an outboard motor needs to own at least a basic 3/8" drive Socket Set and a couple of extensions.