Transducer mount

Blankton · 13 July 2019, 13:07

Hi,
I am after some advice with regards to attaching my fishfinder transducer. I have a yam 310 SIB. I am trying to not drill too many holes in it. The transom already has 2 holes towards the top outboard of the motor mount on both sides. I wanted to make use of these. I assume the 2 holes are OEM as they are nicely lined with a brass collet. Any idea what they could be intended for?

I have made up a bracket from some offcuts of ply, This clamps through the hole. I was quite impressed with myself, however , when planing along, the bracket acts like a syphon and drags water up the transom and floods the boat!

Sorry, no photos of it attached or the syphon effect!

Its not the end of the world, I could just attach it when I have slowed down and am looking for a fishing spot, but it would be nice to see the depth when motoring about.

I have seen some folding transducer brackets, but these seem to be angled for going off the side of a kayak or round tubes. I really just need something to go straight down.

I was thinking something telescopic like that aluminium section used for camera tripod legs or similar. This way I could mark the correct height and drop into place, then withdraw it up slightly if there is any syphon action. Maybe just moving the vertical pole away from the transom would be enough to prevent the syphon thing.

I would be interested to know if anyone had the same problem and/or any materials or off the shelf solutions for a transducer bracket.

Fenlander · 13 July 2019, 18:23

The image that would have been interesting was from behind mounted on the transom so we can see how wide the bracket is and how deep.

Here is my setup when I was deciding on a position. I have settled on one where none of the wooden leg is below the transom so only the transducer itself presents to the main water flow. The top has been cut off flush.

You only need one hole in the transom and it would look loads neater than your bracket clamp arrangement.

You can see the disturbance in the wake but no water over the transom.

mm289 · 14 July 2019, 10:30

I have been playing with this on my FRib, had and adjustable ally mount tthat clamped on but found getting accurate placement was tough and as you found if it is out slightly you get water in or a big rooster tail!

The placement of the transducer relative to the bottom of the hull is critical, most online guides seem to say to run a straight edge allong the bottom of the hull and line up the bottom of the transducer with that.

To get placement right I am using Sikaflex 291 to stick the transducer to the transom so that if it doesnt work I can change it and have no holes in the transom. Once I am happy I might then use the plate that comes with the transducer to give me a small amount of adjustment.

On my latest experiement I was getting a slight wake from the transducer but no rooster or water ingress. Interestingly I could read depth (but not much else) at WOT and 19kn.

The only challenge is the FRib tends to sit quite nose up, so what reads well at displacement or rest is a bit different when you are on the plane, and that is what i am trying to play with at the moment.

Was quite impressed how well the Sikaflex has held on given we spent about 5 hours on the water mucking about.

Cheers,

MM

Fenlander · 14 July 2019, 11:26

How are things going with you mm? I've lost track of where you are with the outfit... did you get an old 2-stroke 15hp or one of the new EFI models? How are you finding the Frib on the sea?

mm289 · 14 July 2019, 12:44

Hi Fenlander, Fribs going fine thanks. Mainly been using it on rivers as there is a lack of launching down here, but had my son back at the weekend so could beach launch happily

Frib is great, given I hope to do a fair bit of beach launching so having a hard floor is much better for me than an airfloor as I don't have to worry about running up onto the shingle.

We have a very nice 15HP Mercury 2S and a 6HP four stroke. TBH the 2S is a much nicer engine, it feels smoother, quieter and doesn't seem to use that much fuel.

I use the 6HP on the river but with 2 of us onboard it won't plane which is a bit frustrating.

Just sorting out my setup to hopefully do a bit more sea fishing this year

Cheers,

MM

Blankton · 14 July 2019, 21:27

Quote:

Originally Posted by Fenlander

The image that would have been interesting was from behind mounted on the transom so we can see how wide the bracket is and how deep.

Here is my setup when I was deciding on a position. I have settled on one where none of the wooden leg is below the transom so only the transducer itself presents to the main water flow. The top has been cut off flush.

You only need one hole in the transom and it would look loads neater than your bracket clamp arrangement.

You can see the disturbance in the wake but no water over the transom.

The leg is about 10mm wider than the transducer mount, just enough extra width so there is enough to meat to get the screws to hold. It finished flush with the bottom of the hull, Ive cut about 5mm off the bottom of it today at a 45 degree angle away from the boat, I am hoping that this will reduce the tendency to suck up the water. We will find out next weekend.....

If I was to drill the transom, the holes would go through the pvc where it folds over the bottom of the transom, which I was really not keen on drilling down that low.

I didn't explain, part of the reason that the bracket is so big is that it has a rod rest mounted to it at the top.