DF working at speed

[striperjohn]

I can't seem to get my unit to hold bottom when I'm running. I works great until I get up on the pad and then I lose bottom. Any ideas? I picked up on this from catfishkings post on relocating his xdcer. I've tried putting ping on max speed, but doesn't seem to help. I've got a LCX111hd

[mwardncsu]

Most likely has to do with getting "clean" water across the xducer.

1) look "forward" from your xducer. Make sure you don't have it mounted in line with any thru-hulls or such that would disrupt the water flow

2) how"deep" is it - Sometimes its too high and will cause it to lose bottom due to too much turbulence. Other times it may be totally out of the water when on plane.

3) make sure it is level - if it has been knocked up a bit, then the angle would result in the signal bouncing off the bottom and then too far aft to be picked up. This would also likely result in "one-sided" arches when you are slow-trolling

Can you post a pic of the xducer on the transom?

[striperjohn]

Tks mike soon as my isp is better i will post a pic. It cones and goes now.

[striperjohn]

After looking at the install, I think it's too deep and too close to the pad runner. Here's a try on the pic

[mwardncsu]

My guess is that is a pretty "noisy" spot with turbulence. Wonder if putting it on the transom end of the pad would be better - do you have a pic of the full transom view?

Also, it is generally recommended to mount it on the starboard (right) side of the motor if you have a clockwise rotating motor/prop. This way you do not have the prop throwing cavitated / agitated water in the direction on the transducer.

This site has some good "rules"

www.sternmate.com/Where.html

[striperseeker]

Looks to me as if the angle is wrong. It appears to be level with the flow of the water or maybe even a tad back. Either of these conditions will cause bubbles to form as the water flows across at high speed. What you need to do is angle it slightly upward so the water pressure scrubs off the bubbles. I would angle it up into the current about ten degrees and see if you don't lock onto the bottom at speed. Having a clean flow of water without any cavitation is necessary for the signal to get through to the transducer. So before you go drilling any holes try changing the angle of the transducer. Always try the cheap easy fix first.

[mytoyzfishing]

Whats "high" speed. On the CC i used to have the particular xducer would loose bottom once I hit above 25 mph. When I called the company they had told me the xducer I had was not what they calked a hugh speed xducer and that I needed to order a diffrent one if I wanted to keep bottom at speed.

[mwardncsu]

If that is the Lowrance 83/200 xducer, I hold bottom on mine at WOT - upper end of the 40's. the 83/200 is the one on the far right. I did have to adjust it down just a little (1/4" - 1/2" tops) from what is shown in the pic.

[striperjohn]

Thanks for the input guys. Mward the Sternmate guys said it "used" to be a problem with older systems and transducers having it on the left, but my install looked ok, etc that like one of the guys said it does need to be tilted up about 10 degrees. I guess the prop wash doesn't effect the new transducers at speed because the wash doesn't reach them.
I have a Scout SF192 Flats boat with a 200 Yamaha on it, it runs about 72mph with just me in it, (too scary!) and I can cruise at 60 with 4 guys and a bait tank. I usually run around at about 44-45 simply because it's way more efficient.
I talked with Lowrance and I have the 83/200 transducer and they said once I get it set right it should work easily at 60mph. The older tech I used to talk to is no longer there. He was recommended by JD a few years back. But the new guys knows his stuff or seems too.
Anyway I'm aching to get the boat out on the water and try to fix this.

[mwardncsu]

Mar 5, 2013 14:09:21 GMT -5 striperjohn said:

I have a Scout SF192 Flats boat with a 200 Yamaha on it, it runs about 72mph with just me in it, (too scary!) and I can cruise at 60 with 4 guys and a bait tank.

Are you sure you don't have some sparkly paint on that boat running at those speeds - of course with a 200 on a 19' flats boat should haul!

[striperseeker]

Wow, 72 MPH, that is flying. Maybe that is why you cannot read the bottom, you are up in the air.