engine mounting

Discussion in 'Bubba's Outboards' started by badbob46, Dec 9, 2007.

  1. badbob46

    badbob46 New Member

    Messages:
    190
    State:
    Louisiana
    this past week , i removed a 1991 25 inch shaft, 120 hp johnson looper engine from my 22 foot bayboat ,, and replaced it with a rebuilt 1988 evinrude 140 hp , 25 inch shaft looper engine..it runs great, but there is a problem..when i installed the new engine i used the same bolt holes in the transom and they matched up fine with the engine mount on the new engine, but when i launched the boat for a test run, the new engine threw water up the transom and into the boat, it also has 2 rooster tails that are hitting on the on the bottom side of the cowl.. my thinking is that the motor is either too deep in the water or not deep enough.. can you tell me whether i need to lower it or raise it up?.. also it might be important for you to know my boat is a semi v tunnel hull. right now from what i can see it appears that the cavitation plate is about 1 inch below the top of the tunnel , if that helps you make a diagnosis..
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    I can't see where the problem would be because a 25 inch shaft is a 25 inch shaft weather it be 1978 or other wise. Do you have a whale tale on it and have you took some one with you and looked down to see what is causing it.

    OOpppsss I know where you are coming from here. I would say you need to lower it one notch because the mounting holes are a little different in where they are located on each engine in prespective to some years.
     

  3. badbob46

    badbob46 New Member

    Messages:
    190
    State:
    Louisiana
    I had my son drive the boat saturday while i got back there and looked, but there was so much water that i couldnt see anything definite..what i did discover on monday tho was on my old engine there is a built in splash guard mounted to the shaft that the engine turns on , its just above the lower unit.. my thinking is that this must have been a problem with those first tunnel hulls when they were coming on the market and this splash guard was OMC's answer to the problem..it's way too big of a project for me to remove it and put it on the new engine tho.it would require removal of the powerhead and there is no way i am going to do that..I did however obtain a hydraulic jack plate yesterday and we are going to try that before we make any other modifications.. thanks for your response and i will post back here again after the jack plate is on and we get it adjusted..