Propeller recommendation

tygh

Cadet
Joined
Sep 9, 2003
Messages
25
I have a 1991 Merc 9.9 outboard on a 10ft Achilles inflatable boat. I have no problems with performance with just me in the boat, but when I load a buddy and dive gear, the performance goes in the toilet.<br /><br />Would a propeller with a different pitch help??? Lower pitch? What would that do for performance when I am using the boat alone?? I am a true newbie to this :)
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Propeller recommendation

Yes, a propeller of lower pitch would most likely help with a big load. But, you would want to switch back to the regular prop. when it's just you. For example, if you are running a 9" X 10-1/2" pitch prop now, you may want to go with the 9-1/4" X 7" pitch prop with a heavy load. The Michigan Prop number for the latter one is 032056. This will fit your motor fine. It's $66.00 HERE. Good Luck,
 

tygh

Cadet
Joined
Sep 9, 2003
Messages
25
Re: Propeller recommendation

Ok, to further show my ignorance, another question. The lower pitched prop will do what to the outboard rpm's? I get 8 knots out of the current prop with a full load. Will speed improve?
 

Hasbeen

Petty Officer 2nd Class
Joined
Aug 29, 2003
Messages
167
Re: Propeller recommendation

The lower pitch prop will make the performance about the same with two as the other prop with one! Dont expect that little motor to do much more than it is!! and yes put the original prop back on when you go out buy yourself!!<br /><br />Hasbeen
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Propeller recommendation

For every 1 inch pitch, you gain or lose 200 RPM's, depending on whether you go up or down in pitch. Therefore, if you go from a 10" pitch prop to an 8" pitch prop, you will gain 400 RPM's and with a load on the boat, that will keep your RPM's where they need to be. But,like Hasbeen said, you can only get so much out of a small HP Motor. All you can do is try it.
 
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