85 johnson 40 h.p. prop

Discussion in 'Bubba's Outboards' started by dearl, Jul 15, 2007.

  1. dearl

    dearl Member

    Messages:
    37
    State:
    North Carolina
    I am currently running a 17 pitch prop, and i want to try and get alittle more top end out of her. My Tracker probably weighs about 1300 pounds, and right now at WOT i can do 31 mph on GPS. Also i have heard tell of the 40, 48 special and the 50 use the same block pistons etc, they are just Carbed diffrent is this true? If i can recarb my current set up and prop it just right and get it in the low 40's I will keep her, if not i might have a motor for sale.
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    You might try a 19 pitch and see if it will pull it but I am guessing you will slaughter the RPM's that is a lot of prop to turn with a 4o h/p
    If you want hole shot you will need a smaller prop. If you want top end I would have a cup added to that 17 pitch and it will get it a better bite with less slip and better fuel mileage.

    The difference in those motors you are talking about is a lot more then carb jets. You have the exhaust that is different and different throat openings in the carbs them selves. Different reeds.
    If you have that motor in the 70% bracket of what your boat will carry then you may be better off just maxing your boat motor capacity out for that particular boat.
    You can try raising your motor one notch at a time and see where it will perform best. You can also add a jack plate to set the motor back about six inches and then start raising it and that will increase your x factor on the drag that is slowing you down.

    You need to keep in mind you will only go as fast as that hull is designed to do before it starts to chine walk and then its in a dangerous situation then.