Is this cavitation or lower unit problem

Discussion in 'Bubba's Outboards' started by Bluerider, Jul 14, 2008.

  1. Bluerider

    Bluerider New Member

    Messages:
    23
    State:
    Bethalto, IL
    I have a 1994 30 hp Johnson tiller.

    Lately I have been having a harder time getting on plane with no changes in load or distribution of load.

    When I do get on plane it runs great for a short distance and then the motor rpm sounds like it increases sharply (no tach) and it feels like the prop is slipping enough to fall off plane.
    Throttle down and try again, sometimes it will jump right back up on plane and sometimes have to fight it a bit.
    Motor never kicks out of gear.

    Replaced prop last year with stock pitch and ran all season with no problems. No damage to prop.

    Any input would be appreciated
     
  2. catfishjon

    catfishjon New Member

    Messages:
    156
    State:
    texas
    Sounds like the props rubber insert is slipping. Install an old prop that is good and see if you have the same problem. Catfishjon
     

  3. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Take the prop off and take a marks alot and make a mark all the way across the hub and replace it and run it. Take it off after it does it again look at your marks and see if they are still inline. if not then rehub it. You said a new prop from last yeay, have you hit anything or it may just have been a bad rubber insert in the hub. But it does sound like a spun hub.
     
  4. Bluerider

    Bluerider New Member

    Messages:
    23
    State:
    Bethalto, IL
    Thanks,

    I'll give that a try.
    No I haven't hit anything and prop still looks new, that's why I was kind of not sure exactly what was causing the problem.
    Like I said, sometimes it runs just fine.