different prop photos

rich_1833

Recruit
Joined
Jun 28, 2010
Messages
4
I bought an 1985 Glasstream 1550 bass boat with a 1985 mercury 50 hp outboard. The boat is 15' 6'' long with a 68' beam and weight is 700lbs. Anyway it come with 2 different prop. I looked both props up online and they seem to be the same pitch but they don't look the same to me. Maybe somebody can tell me the difference? The 1st pic is both props. The 2nd is the bottom prop in the 1st pic. The 3rd photo is the top prop in the 1st pic.



IMG00099.jpg




IMG00101.jpg




IMG00100.jpg
 

Bifflefan

Commander
Joined
May 27, 2009
Messages
2,933
Re: different prop photos

Without the numbers off them,

the one on the boat seems to have less cupping than the other, and it is a bit different down where the leading edge and the hub meet.
The proformance is probably the same for the most part, with a very minor difference.
If this is a new to you boat id say you have a spare prop.
 

rich_1833

Recruit
Joined
Jun 28, 2010
Messages
4
Re: different prop photos

in the 1st pic the top one is a Michigan wheel 031019 and the bottom a mercury oem 48-73140A40
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: different prop photos

These are both 10-1/2 x 15P props. The 013019 is a Michigan and the other is the OEM equivalent. What you are seeing is what we often call "design" differences between manufacturers. While these two props may perform similarly, they may not either. The one prop does definitely have more cupping which is usually good for one more pitch number over a non-cupped prop assuming all else is equal. The only way you will know which is best is to run them. The best prop is the one that allows the engine to rev at or very near the top of the manufacturers recommended WOT rpm band. Speed and hole shot will be whatever that prop provides.
 
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