Fish Finder Problems

Discussion in 'Fishing Electronics Review' started by topfuelkc, Jul 9, 2008.

  1. topfuelkc

    topfuelkc New Member

    Messages:
    77
    State:
    missouri
    :crazy::confused2:Im having a problem with my Humminbird 383c fish finder,the problem is that as soon as my boat starts to get up on plane I lose my bottom signal and it goes to 200-300 ft. deep.I have moved the transducer in different locations and followed the directions that came with the unit.I have made many small adjustments and wrote humminbird and all they say is it's out of adjustment. well i dont know how many more ways I can adjust it. It is mounted on the back of my aluminum boat. Has anyone else had these problems. I would like to find someone who could help me set up this thing so it would be usable. I have trid everything I know. It's not the best fish finder but for almost $400.00 it should work better than it does. Thanks
     
  2. Mr.T

    Mr.T New Member

    Messages:
    2,553
    State:
    MO
    Any time your sonar loses the bottom at higher speeds, it's because the transducer is not in an undisturbed flow path - sonar transducers need to be surrounded by water and only water, but once the boat gets going, turbulence and/or air bubbles are getting mixed into the water as it flows under your boat and around your transducer. And no sonar in the world can handle that no matter how expensive.

    If you're using a flat-bottom jon boat, you're going to have air bubble problems. Best you can do is try to mount your transducer as far down below the hull as possible, centered between two keel strips if your boat has them and generally close to the centerline of the boat. The danger in mounting it that low is that it's likely to break off if you hit something just under the water.
     

  3. jerry9497

    jerry9497 New Member

    Messages:
    512
    State:
    Tobaccoville NC
    I have that same model and love it. have had no problems with it. and a pretty decent fishfinder to. I use it for my high speed because my other is a 997 and it lacks on high speed. I think it probably is the flat bottom but others here have flatbottoms and I havnt heard this much. my "high speed" is 25mph on a pontoon boat. If your running faster in a flatbottom... I cant picture clean water for it. If it is a small flatbottom jon.
     
  4. topfuelkc

    topfuelkc New Member

    Messages:
    77
    State:
    missouri
    Humminbird says mount it at least 16" from the prop in which I tried and I do have it mounted between two keels I did lower it and changed the angle some but have not had it back in the water yet. I will let you know how it does this time.
     

    Attached Files:

  5. jerry9497

    jerry9497 New Member

    Messages:
    512
    State:
    Tobaccoville NC
    in the picture it looks way out of adjusment, and mounted to high. as you run your hand down the bottom of boat, transducer should be just below the bottom. my mounting plate for transducer is just above the bootom of boat. it will kick up if you hit something small with it but it is down below the bottom of the boat...just enough and trans should be parallel to bottom of lake (level at plane speed)
     
  6. Pacman

    Pacman New Member

    Messages:
    141
    State:
    South Carolina
    I mounted one in the live well that did well. (fiberglass or wood) Just thought it might be another possibility if you've tried everything else.
     
  7. Mr.T

    Mr.T New Member

    Messages:
    2,553
    State:
    MO
    That's about 99% of your problem right there.

    the *top* of the transducer should be roughly level with the *bottom* of your boat. The transducer needs to be level (front to back and side to side), not angled up or down.

    I'd move it over to the center of the two keel strips just to the right of the drain plug hole (just left of the "26" in your photo), drop it about 2" and get it level.

    If you have any friends nearby who are more experienced, you ought to seek their help. Or if all else fails, read the installation manual; they all give pretty good and clear instructions...
     
  8. rwilley3

    rwilley3 New Member

    Messages:
    1,389
    State:
    Brighton, Tenne
    I had a lot of problem at first similar to what you describe. I mainly fish the Mississippi River which is very muddy and hard to see the transducer a lot of times. I took a trip to the TN River and actually looked over the back of the boat while I was driving at higher speeds(be safer if someone else drove and you look:smile2:) and see what the transducer looks like where it is mounted. I ended up moving mine over and actually raising it up more than I originally had mounted it to get it in some less turbulent water. Mine does 1000% better since I have done that.
     
  9. BailBonds

    BailBonds New Member

    Messages:
    282
    State:
    Indiana
    I made a smooth transition from the hull to the transducer with silicone caulk. Filled it in a little at a time. Wish I had a photo but I was loosing the bottom at any speed over idle. Just filled the area with caulk. Perfect picture after that.
     
  10. daddio

    daddio New Member

    Messages:
    260
    State:
    kansas
    while we are on fish finders i have a cuda 168, last year it worked fine now it reads 60ft when im in 4ft ? any ideas
     
  11. topfuelkc

    topfuelkc New Member

    Messages:
    77
    State:
    missouri
    Well Jerry I moved the transducer over like you said closer to the center and also lowered it down so it is level with the bottom of the boat. I'm putting in the water tomorrow and trying it out. I'm fishing a Cat tournament at Carlyle lake. Maybe I'll see ya over there. I'm bringing some tools So i can make some adjustments if needed. I've got a white 20' WACO Big Boy boat. This will be me and my partners first Cat tournament.
     
  12. topfuelkc

    topfuelkc New Member

    Messages:
    77
    State:
    missouri
    Well after moving the transducer over closer to the center the problem that I was having has been greatly reduced. Thanks to everyone for all the advice.:big_smile:
     
  13. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Ted, I'm having the same problem. Think mine got hit by a tennis ball sized hail stone. Guess I'lll just get another one. At $68.00 I don't expect much and its not that big of a loss. LOL I notice that when it starts cycling through the depths, it has changed into the sonar (demonstration) mode. Can't keep it set anywhere else.