Garmin 120 fishfinder problem

[steviecops]

I recently bought a new Garmin 120 fishfinder. Garmin say that the unit will work at high speed, but when I took it out today, the display disappeared at anything over 8 knots and the unit started giving false depth readings, ie 97 ft when I know the depth was only 30 ft.<br /><br />I followed Garmins recommendations and fitted the transducer to the transom in the location they described.<br /><br />Does anyone know why the unit is behaving like this? Is this normal, and if not, is there anything that can be done?<br /><br />Thanks<br />Steve

 

[rc581]

Re: Garmin 120 fishfinder problem

did you follow the instructions carefully? and is your tranducer level when the boat is in the water/.. is sounds like your getting alot of cavitation. factory says they will read accurate at all speeds, but i never owned one yet that did.....bob

 

[jimchere]

Re: Garmin 120 fishfinder problem

Had the same problem after installing a new 160. I angled the transducer a little more forward (the aft part of the xducer down a bit) and it reads good up to 30, where my boat tops out. Try playing with the xducer angle fwd/aft a little. Actually, what I did wrong when installing (boat on trailer) was to install one of the shims in the mount because that seemed to make the xducer parallel with my keel. I took the shim out and it works great. You may need to take out the shim (or put one in).

 

[steviecops]

Re: Garmin 120 fishfinder problem

Thanks for the advice guys.<br /><br />I did follow the instructions carefully when installing the transducer, though I must admit, I haven't checked to see if it is level with the boat on the water. I installed the transducer with the boat on the trailer, and it looks as though it is parallel with the boats keel. I'll do as you suggest and play around with the angle. First I'll try lowering the back end of the transducer to see if I can get a good result like Jimchere.<br /><br />Thanks a lot.<br />Steve