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  1. #1
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    USA Looking for a prop suggestion. Tin boat 70 Hp. 4 blade????

    I am running a 13.25 17P SS powertech prop. I run about 31-32 MPH. When I trim up about half way between fill down and 3/4 of the way up on my trim gauge the boat wants to porpoise. would anyone recommend a 4 blade aluminum prop. I want to maybe find a 15P. My old 15P 3 blade aluminum prop I was turning 5850 rpm. I want to try and find a 4 blade prop that is a 15P or smaller. Max RPM is 6000 for my 01 2 stroke

    Anyone have an suggestions

  2. Moderator 21XDC's Avatar
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    #2
    Look into the mercury spitfire. Get the bigger diameter model if possible

    Marks Props 317-398-9294, 1850 East 225 South, Shelbyville, Indiana 46176 propellerman59@gmail.com http://www.marksprops.com/index.html

  3. Member
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    #3
    I have a 75 hp four stroke mercury with the 4 blade spitfire x7 alloy prop 13 1/4 x 17p. While the boat handles a little better I am not getting enough rpms. Speed has been 35 mph and 4500 rpms with 2 people so I am also looking for options or another prop also.

  4. Moderator 21XDC's Avatar
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    #4
    Reduce pitch to get the rpms desired. 200 rpms per pitch. Motor may be mounted too low on the transom as well...

    Marks Props 317-398-9294, 1850 East 225 South, Shelbyville, Indiana 46176 propellerman59@gmail.com http://www.marksprops.com/index.html

  5. Member
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    #5
    I have a 70 Yamaha 2 stoke. So would you recommend a 13P 4 blade. I was running a 15P 3 blade and turned 5850. So if I run a 14P 4 blade I will probably turn the same, so to reach my max I should run a 13P?

  6. Moderator 21XDC's Avatar
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    #6
    Probably a 14 pitch. But I am guessing

    Marks Props 317-398-9294, 1850 East 225 South, Shelbyville, Indiana 46176 propellerman59@gmail.com http://www.marksprops.com/index.html

  7. Member
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    #7
    Quote Originally Posted by 21XDC View Post
    Look into the mercury spitfire. Get the bigger diameter model if possible
    Sir, why would you recommend a larger diameter with the 4 blade?

  8. Moderator 21XDC's Avatar
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    #8
    Better holeshot, acceleration, load carrying, handling, will run higher on the transom etc.

    Marks Props 317-398-9294, 1850 East 225 South, Shelbyville, Indiana 46176 propellerman59@gmail.com http://www.marksprops.com/index.html

  9. Member
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    #9
    I have narrowed it down two props:

    1. Solas Amita 13.25" x 13"P 4 blade aluminum prop.

    2. Solas HR Titan 13.25" x 15"P 4 Blade Stainless Steel prop.

  10. Member
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    #10
    bump for any new info

  11. Member
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    #11
    Quote Originally Posted by G3Ray View Post
    I have narrowed it down two props:

    1. Solas Amita 13.25" x 13"P 4 blade aluminum prop.

    2. Solas HR Titan 13.25" x 15"P 4 Blade Stainless Steel prop.
    every solas i have run has been stiff in pitch at least an inch, sometimes 2.
    2022 Hog Island Skiff
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