What size prop

Discussion in 'Boat Tips' started by CNTRYBOY, Feb 17, 2007.

  1. CNTRYBOY

    CNTRYBOY New Member

    Messages:
    1,573
    State:
    Benton, Ar
    I just purchased a 1990 Bayliner "Cobra". It has a 115 hp motor on it. The previous owner said the prop was too big, and that i might want to replace it with a smaller prop. What size of prop would you suggest?
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Newton do you have the prop that the previous owner said was to big? If you do the take that prop and see what RPM's the boat turns with it on. A rule of thumb if it isn't turning enough RPM's to keep it in the right range then to drop a size. You should gain 150 to 200 RPM's for every size you go down in sizes.
     

  3. CNTRYBOY

    CNTRYBOY New Member

    Messages:
    1,573
    State:
    Benton, Ar
    The prop that is on it is the one that he said is too big. So, yes I have the prop. I have not taken it out on the water yet, so I really am only going by what he said. The way I understand it is that if you have more than one person in the boat, then it does not take off and plane out good without putting a person up front!
     
  4. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    I would start by giving the motor a good tune up. It may not be running at 100% and if its not that will happen and make you think the prop is at fault.

    Newton I am assuming here we are talking outboard. Do a compression ck and install new plugs. Do a good decarb and test it before you go putting parts on it.
     
  5. special liberty

    special liberty New Member

    Messages:
    295
    State:
    Maryland
    go to iboats.com I believe they have a section in their forum srictly on props and prop selection. It's a real good website/forum for boat tech questions
     
  6. Little Mac

    Little Mac Active Member

    Messages:
    1,828
    State:
    NW Arkansa
    I dont know about the prop Newton, But Congratulations on getting yourself a boat. Enjoy it.......Mac