Transducer problem on muddy bottom?

[MDSmith370]

I went to the northern point of the Bush River this morning for the first time and my first time out this year. FF was working fine on my last trip last fall. I started to paddle out the boat launch and everything was fine but then when I hit open water the depth finder went to zero and stayed there the entire time I was out. I was relegated to the fact I was going to have to replace the transducer. But as I was approaching the launch ramp it suddenly started showing a reading again. I paddled around a little bit and as long as I was over the gravel or concrete bottom of the launch area it worked. The bottom of the river is a thick muddy/sandy mixture that your paddle will almost get stuck in if you poke the bottom. I fish the flats, bay, and OC so a soft sandy bottom isn't a problem. Any ideas? Could it just be this specific bottom or do I have an equipment problem? Also, the wires where I connect to the battery got a little frayed over the winter and I only had a few strands providing power. Could it be a power issue?

[DOGFISH]

I would fix the power problem first. Just by chance it made a connection as you were returning to the ramp. However, the whole unit would have gone off if it didn't have power and not just reading zero. Then try adjusting you settings. A mud bottom will read different. You may need to adjust you sensitivity. There may also be a fresh and salt setting you would want to set. I had a similar problem in water that is moving, like on the upper Potomac. Water with a lot of oxygen will also cause strange readings. Also, was the transducer connection to the head unit solid. If that was not tight, it may be the problem.

[MDSmith370]

Thanks for the response. It had power the entire time. The sensitivity was defaulted at 5 and I cranked it up to ten and nothing changed. I didn't try turning it down. I just use a pretty basic Humminbird PiranhaMax 170 and I don't think it has a fresh/salt setting. I guess I need to take it someplace I've been before and see what happens.

[mi327]

You shouldn't have a problem with it in the muddy bottom, I have a PiranhaMax 160, with the skimmer transducer suction cup mounted to bottom of my Yak and I always get a depth reading fishing the Bush River. At least the section between the soft launch on RT 40 and Otter Point, besides the really shallow sections but the manual says it doesn't work in under 3 feet of water.

[MDSmith370]

I launched at Otter Point. I have it mounted with the Goop method in the hull. I know of the bubble problems and experienced it when I first mounted it 3 years ago. I screwed up the first transducer trying to remove it and I got the 2nd working fine and then I completely sealed the sides so nothing could get in. It's worked great for the past 2 years and it hasn't budged. I wonder if it's possible that over time the Goop changed molecularly and isn't allowing the sonar to get through as easily and it's not strong enough to bounce back up off the soft bottom but can off the shallower hard bottom. I'm reaching now.

[J.A. Veil]

I wonder if it's possible that over time the Goop changed molecularly and isn't allowing the sonar to get through as easily and it's not strong enough to bounce back up off the soft bottom but can off the shallower hard bottom. I'm reaching now.

I'm sorry to hear you are having problems. In my experience, the Goop adhesion bond does not change over time nor does the sensitivity of the transducer. I second the idea of making sure you are getting all strands of your power leads to the connector. If some of the strands are frayed or corroded, cut off an inch or so and re-splice new connectors.

Before taking it to a repair shop, I suggest trying it at another location where you know there is a muddy bottom. If the problem re-occurs there, then something is wrong.

[mi327]

I'm sorry to hear you are having problems. In my experience, the Goop adhesion bond does not change over time nor does the sensitivity of the transducer. I second the idea of making sure you are getting all strands of your power leads to the connector. If some of the strands are frayed or corroded, cut off an inch or so and re-splice new connectors.

Before taking it to a repair shop, I suggest trying it at another location where you know there is a muddy bottom. If the problem re-occurs there, then something is wrong.

I am also wondering if it is possible that the through hull transducer isn't far enough under water to get a good reading on the soft bottom?

[mi327]

MDsmith, if you are going to be fishing out that way, I live nearby and may be able to help you with a transducer test with my suction cup mounted one.

[MDSmith370]

I went to the flats this morning where I know the transducer has always worked and I still have a problem. The power wires have been repaired and the transducer is found as connected and the temp reading is fine. The first 20 minutes the reading was zero depth and then it suddenly came on. I was fishing in 25-40 feet the entire time and it would work for 15 min and then the reading would go to zero for 10 min then suddenly back on. It did this the entire time. I put a motor on a few weeks ago and after seeing mi327's comment about water level made me think the heavy battery and motor on the back was lifting the front higher and maybe the transducer was raising above the water line but I went to shore and removed the battery and motor and it didn't help. The FF worked fine all last year and the transducer is rock solid to the hull. Any suggestions on unGooping a transducer?

[J.A. Veil]

I went to the flats this morning where I know the transducer has always worked and I still have a problem. The power wires have been repaired and the transducer is found as connected and the temp reading is fine. The first 20 minutes the reading was zero depth and then it suddenly came on. I was fishing in 25-40 feet the entire time and it would work for 15 min and then the reading would go to zero for 10 min then suddenly back on. It did this the entire time. I put a motor on a few weeks ago and after seeing mi327's comment about water level made me think the heavy battery and motor on the back was lifting the front higher and maybe the transducer was raising above the water line but I went to shore and removed the battery and motor and it didn't help. The FF worked fine all last year and the transducer is rock solid to the hull. Any suggestions on unGooping a transducer?

Un-Gooping a transducer can be tough. The adhesive bond is very strong. A few years ago I bought a used Gheenoe with a fiberglass floor. I Gooped my transducer to the inside of the floor. It worked fine. However, when I sold the boat a year later, I removed the nice fishfinder and transducer to use with the newer boat I purchased. I had a hard time chiseling and prying the transducer + Goop from the floor. Then I spent half an hour physically removing the Goop from the transducer before remounting it on my new boat (an exterior transom mount this time). You may have a simpler time removing the transducer from a polypropylene kayak surface than I did.

Sorry to hear about your ongoing problems. If the unit is several years old or is a low-end model, it may be worth replacing it with a newer. more sophisticated unit.

[mytmouse]

Before you remove the Goop, do you know anyone that already has a PiranhaMax installed? That way you can do a little swap to make sure that it indeed is the transducer and not something funky within the unit.

[MDSmith370]

Thanks, John. The 170 isn't a sophisticated unit but I like it and it does what I need it to do (when it's working of course) and it's only about 2 years old. Mytmouse, I don't know anyone with this FF. I checked the pins on the transducer plug and I see some green corrosion on there so I am going to clean the pins and give it another shot before I do anything else.

[jet]

i had my ducer gooped and 3 years later i had problems, at least i thought it was working fine for those 3 years. basically it started pulling away at the edges. when i pulled it off(which was easy for me), i couldnt believe how many bubbles where around it. side note, ive passed over boat wash in creeks and docks, 9' or less of water when they pull out and kick tons of silt into the water, and my ff goes crazy, not knowing bottom. another note, ff have some depth and sensitivity settings which you should play with, which i am still strying to figure out on my new one.