40 evenrude. slow on john boat

Discussion in 'Bubba's Outboards' started by Cattracker16, Jul 11, 2006.

  1. Cattracker16

    Cattracker16 New Member

    Messages:
    356
    State:
    Wilton Iowa
    I bought a rude motor from a guy 3 years ago. I put it on a 18 foot john it has a whale tail on it. it seems to smoke going up out of the hole.. the thing is it doesn't seem to go fast. it was on a 20 foot pontoon boat b4 does the size of the prop matter? i have found that if i don't trim the motor back down b4 taking off the whole back of the boat will come out of the water and i loose contact with the water. do i need to look for a smaller prop? and if i need a diffrent prop what size do i look for?
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Your prop is definately part if not all of the problem.

    You've probably got an 11" pitch prop and need to go up in pitch to about a 14" pitch or better.

    Look inside the hub for prop size
     

  3. Arkie55

    Arkie55 New Member

    Messages:
    669
    State:
    Mississippi
    Cattracker,
    I bought a 60hp Johnson that had spent it's whole life on a toon. The prop was a 13 pitch so it could power the toon. I had to change to a 17 pitch prop to get the motor to perform properly on my boat. It's likely you prop pitch is to small is spinning out in the water because it can't cup enough water. Your motor is probably over reeving too. I would get at least a 17 pitch prop and try it.
     
  4. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    !7 pitch worked on a 60. Do you really think it would work on a 40?
     
  5. Cattracker16

    Cattracker16 New Member

    Messages:
    356
    State:
    Wilton Iowa
    i don't know if these are the right #'s or not but i have the xtra prop in my hand and it says on the rubber cuppler propco 13 R .
     
  6. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Before you buy props invest in a tach. Best money you can spend on a boat.
    Outboards are expensive to replace and repair.
     
  7. Arkie55

    Arkie55 New Member

    Messages:
    669
    State:
    Mississippi
    Naw, you're probably right BobPaul. 17 pitch would probably be to much. If he has a 13 then he needs to try a 15.
     
  8. Cattracker16

    Cattracker16 New Member

    Messages:
    356
    State:
    Wilton Iowa
    That sounds like a good starting place.. I'll have to go get me a new prop to see what the boat will actually do. i think it should go atleast 25 - 30 mph. with the 13 it'll do about 19 WOT and trimmed up rmps i believe are around 5000 - 5300 i don't use the boat that much but would like to use it more since the water level is falling in the mighty miss