Advise on proper size and pitch for 2005 Mercury 50hp ELPTO motor.

jreedham

Cadet
Joined
Jun 23, 2012
Messages
11
Label on lower unit says 12 x 22, but prop on motor is only 10" diameter and pitch is unknown. Need a spare and want to buy the right prop.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
12/22 is your gear ratio divide 12 into 22 you get 1.83.this means the motor turns 1.83 times to the props once.
Gear ratio is important in doing prop calculation.Your pitch is usually near the base of the blades or under the prop nut.
Now is the time to evaluate your setup a time to fine-tune your prop selection.Usually by selecting a prop that produces the best speed
will result in the best performance and economy.Tell us about your boat.
If you do a lightly loaded wot(wide open throttle) test and get us the prop size and the rpm and a gps speed.Most cell phones can have a gps app.
If you just want a spare use the numbers on your prop and order one here at iboats, Feel free to ask any questions.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
The right prop is only possible through experimentation under trial and error. Should start from factory delivered prop, Call Merc Marine and ask what's the standard factory delivered prop that came with that engine, can go from there maximizing prop pitch to suit your personal boating requirements. Are you assuming it's not the factory delivered one ?

Happy Boating
 
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