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View Full Version : Two problems - Fish tail caused by Transducer and Bogging down


Disturbed
08-14-2012, 10:16 AM
Issue 1) So, this past weekend, I replaced my old cheap Humminbird that came with the boat and put a new Humminbird 788 GPS/fishfinder on. The transducer was slightly different but I mounted it in the same place as the old one. I noticed that above 35mph, I have a fishtail that sprays straight up the back of the boat and basically onto the engine at high speed.

Issue 2) This may be related to issue 1. I was cruising along doing about 35 when all of a sudden the engine severely bogged down. It sounded as though I was getting water sucked in. It would not go above 2500 RPM and 13mph. After about 20 minutes, I removed the engine cowling and checked everything. I found that the host at the very bottom of the intake had come off. I'm ASSUMING that the water spraying up from the transducer was possibly getting into that hose and sucked into the engine causing it to bog down. As soon as I reconnected the hose, away I went without a problem It then came off about an hour later, and the same scenario. The third time it came off, It had split at the end. I cut the hose to get a good connection (barely enough length left) and will be getting a new one today. Does this sound right? Water getting into that hose through the engine cow? It seemed to fix the problem each time I put the hose back on, and only at high speed when water was spraying high enough to get onto the engine.

Should I mount the tranducer lower down on the boat? Itis picking up fish fine (or appears to be), and I only lose readings at high speed. Normally we cruise at about 23-25mph.

It was an extemely calm dayout on the water (0-1ft) seas in South Florida, right off of Jensen Beach. It was almost like glass. But it was a rough day for us. Did I mention the dead battery at the start? Lmao. That was my fault. We added a 6 speaker stereo, amplifier, and fish finder, and like a dumb@$$, I never charged the battery. I just got a 2nd battery and dual battery switch to alleviate that problem in the future.

Any thoughts would be much appreciated. Sorry for the novel.

jasoncooperpcola
08-14-2012, 10:24 AM
How far below the bottom of the boat is the transducer? Should be around 1/8".

Disturbed
08-14-2012, 10:29 AM
It is right at the bottom, but about 1 foot to the right of the engine. should it be dead center, like below the plug?

jasoncooperpcola
08-14-2012, 10:36 AM
No you dont want it there. The best place is behind a horizontal strake. You should move it down. And use a straightedge on the strake to get it perfectly 1/8" or what your book says it should be.

RWilson2526
08-14-2012, 11:18 AM
if your humminbird transducer is like the one I just added a little while ago make sure you installled the rubber plug that comes with it that fills the space between the transducer and the transom in between the mounting bracket. I forgot to put it in and got huge rooster tail.

edit: just did a little research and found that maybe not all the humminbird transducers were shipped with the rubber plug (comes with "high speed" transducers apparently) A work around is wrap some electrical tape around the opening.

Disturbed
08-14-2012, 11:36 AM
Thanks, I didn't get one, but will add the tape. I'm going to check the positioning of mine as soon as I get home and make sure that the angle is properly adjusted. I think I did the angle correctly, but will be sure to double check. It might need to go lower down though, because if memory serves me correctly, my old transducer was longer, so this one may not be sitting quite low enough.

draglink
08-14-2012, 06:00 PM
I love Jensen Beach! Are you old enough to remember Shuckers?

Disturbed
08-15-2012, 08:42 AM
@Draglink. My wife and I went there quite few times before it was destroyed completely.