Prop spinning out?

Discussion in 'Bubba's Outboards' started by weathermantrey, Apr 28, 2006.

  1. weathermantrey

    weathermantrey New Member

    Messages:
    516
    State:
    central,sc
    i just got a new evinrude etec 60hp on my 24pontoon. I pitched the motor and got the right sized prop. only problem is, at WOT the prop spins out and the motor revs up. This only happens at WOT combined with hitting a little wake or something. I was thinking maybe a tail fin or something would help. any suggestions? My old motor didn't have this problem and it had a tailfin installed on it.
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Need to lower the motor down one notch to keep the prop in the water at WOT. When installed it was mounted to high on the boat.
     

  3. Dragger

    Dragger New Member

    Messages:
    538
    State:
    North Carolina
    I agree with Willard, The motor is to high, thats called cavation, at WOT the prop is blowing all the water away. on a pontoon the cavation plate should be some where around 1 1/2 inch below the bottom of the motor pod , thats what works on mine , hope this helps.........
     
  4. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    You can't set up a pontoon like you do any other hull. The motor has to be lower, and definately no hydrofoil.
     
  5. weathermantrey

    weathermantrey New Member

    Messages:
    516
    State:
    central,sc
    the motor is already adjusted to the lowest notch. and the motor is mounted as far down as it can go on the motor mount. Any other things i can do to help this problem? When we took it out I had a ton of weight on the toon. So i'm hopeing maybe it won't blow out at all with less weight. If there's nothing else I can do i'm content with it. It only does it at WOT when i hit some wake. I'm fine with not running at WOT anyways, the last bit of throttle doesn't really make me go much faster anyways.
     
  6. blackwaterkatz

    blackwaterkatz Active Member

    Messages:
    3,659
    State:
    Andrews, SC
    Trey, do you have the right length motor? I would assume the pontoon needs a long shaft motor. If that's the same, how about your prop. Is it a cupped prop? The cup helps prevent cavitation, too.
     
  7. weathermantrey

    weathermantrey New Member

    Messages:
    516
    State:
    central,sc
    I went outside and it looks like the cavitation plate is a good 3 or 4 inches below the bottom of the motor mount hull when trimmed all the way down.
     
  8. blackwaterkatz

    blackwaterkatz Active Member

    Messages:
    3,659
    State:
    Andrews, SC
    Since you mentioned 'trimmed down', what postition is the trim in when the prop cavitates? On a pontoon, you really don't need to trim much past horizontal. If you trim too far out, that could also cause cavitation. Have you tried different trim angles to see if that helps?
     
  9. Nobody Special

    Nobody Special New Member

    Messages:
    614
    State:
    TN
    I had a pontoon and had to keep the majority of the weight to the rear. Too much up front and the back of the boat would come up too high.
     
  10. Catgirl

    Catgirl New Member

    Messages:
    13,546
    When that happened under a full load did it spin the hub or cavitate the prop? If it spun the hub you'll have to replace the prop or it won't stop doing it. When it cools down it will seize back up and work normally, until you put it under a hard load, and then it will spin again.
     
  11. weathermantrey

    weathermantrey New Member

    Messages:
    516
    State:
    central,sc
    i've treid all different trim angles. i went out yesterday and tried it out again, it'll only spin out when everybody sits at the front of the boat. when my two friends sat in the back it did just fine. plus i have a 35gallon bait tank on the front of the boat. So i figure at 8lbs per gallon that's well over 250lbs. Im gonna take it off and mount it on the back of the boat. i think that'll pretty much solve my problem.
     
  12. blackwaterkatz

    blackwaterkatz Active Member

    Messages:
    3,659
    State:
    Andrews, SC
    Chris, I think you found the problem, as mentioned earlier by Grumpy. Usually those bait tanks need to be near the center of the boat, or slightly toward the rear, at least the few I've seen. It definitely sounds as though you have too much weight in the front.
     
  13. Hookman

    Hookman New Member

    Messages:
    56
    State:
    dELYRIAs ohio
    is there a chance the prop is the wrong pitch.?....hookman....