what are my options?

newbie_owner

Seaman
Joined
Apr 26, 2008
Messages
72
I have a 69 mercury 50HP on the back of my 71 MFG Gypsy 14'. I just wanted to know what kind of prop I should get that would help me to plain faster.
 

K.P.

Seaman Apprentice
Joined
May 29, 2008
Messages
39
Re: what are my options?

What diameter and pitch prop do you have now and what kind of RPM's are you getting at wide open throttle (WOT)?
 

newbie_owner

Seaman
Joined
Apr 26, 2008
Messages
72
Re: what are my options?

So the numbers on the prop are:

15p A1
31085
16701

I am guessing 15p is the pitch, but the rest I have no idea.

as for the WOT RPM's, my Tach does not go any lower than 2000 RPM even when the engine is off. When I am WOT it reads 5500, but I am not sure if that is 3500 or 5500.

Thanks
 

newbie_owner

Seaman
Joined
Apr 26, 2008
Messages
72
Re: what are my options?

I measured it with a tape, and it is 10 inches from tip to tip.

So its 10 inches diameter and 15p and running 5500RPM at WOT. What Can I change it to in order to plain faster?

Thanks
 
Last edited:

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: what are my options?

I measured it with a tape, and it is 10 inches from tip to tip.

So its 10 inches diameter and 15p and running 5500RPM at WOT. What Can I change it to in order to plain faster?

Thanks

With a 3 blade you need to measure from center to tip and multiply by 2.
Generally the diameter will follow the application may vary some brand to brand pitch to pitch.If 2 or 4 blade youve got it tip to tip.
You need to confirm the rpm/tach perhaps borrow a shop tach.
If your really at 5,500 you are at the rated max rpm.If you can get a gps speed it will help determine where your really at.Get us the max rpm and speed we'll go from there.The health of your motor depends on the proper setup.
 

rainbro

Cadet
Joined
Jun 18, 2008
Messages
18
Re: what are my options?

I have a 13p 10 1/4 "on my heavy gauge 14' aluminum v-hull it jumps out of the water with an 83 merc 50hp.You may have to limit wot as not to overrev.
 

newbie_owner

Seaman
Joined
Apr 26, 2008
Messages
72
Re: what are my options?

Ok,

I finally have all the info:

Fully loaded 5500 RPM @ 28 MPH.
 

junior1113

Senior Chief Petty Officer
Joined
Jan 29, 2009
Messages
763
Re: what are my options?

smart tabs would help hole shot. or a 13pitch 4 blade
 
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