I have been trying to solve the problem of "fish" appearing on my fishfinder when I accelerate. I read a post from Fishing Eagle about transducer position, so I carefully changed the position of my transducer like he suggested. I am still having the problem. I have had similar problems on other boats caused by electrical interference from the ignition system. Those boats had V8 engines and I was able to purchase resistor spark plugs and a resistor for the coil wire, which eliminated my problem back then. I have found no such products available for my little 50hp Yammi.
I now have a Humminbird 717 finder, which works pretty good. I have a Humminbird 788ci that will arrive on Thursday, so I want to figure out this problem before the new finder arrives.
I spent a good part of the day yesterday re-routing my Transducer cable to the port side of the boat, away from any electrical cables. I had to drive a ways to locate a 10' extension cable because I had to rout the cable all the way around the bow. (open bow boat)
I'll post up after fishing on Tuesday. If this doesnt work, I think I'll try the transducer inside the hull.
Any other suggestions??
Does increasing the upper limit on the sounder do anything to avoid reading bubbles from the hull??