Transducer reading

I just put a new Lowrance Elite HDI-Elite 7 on my 1990 Ranger 375V, I am having trouble with the transducer. It reads great when idling but as soon as I pick up speed and go to get on plane I lose signal. My boat won't really go that fast, only about 55 mph if I push it, so I don't think it's a speed problem. I've placed the transducer on the right side of the transom and just above the bottom of the boat. I can't figure out if I need to raise the transducer or lower it below the bottom of the boat, I want to figure it out without having to go through trial and error with drilling holes in my boat....any suggestions? The 1990 375V has two strakes on the bottom of the boat both left and right and my transducer is sitting above the right side strake, could this cause a problem?

I'm having the same problem with my new humminbird I wrote to customer report and they told me that I may have to move my transducer up to 16 inches away from the prop to get out of the prop wash and also to make sure the the transducer is a 1/8 to 1/4 inch below the bottom of the hull and also may need to angle the transducer but no more than 7 dergrees up and make sure there was no electrical interference so instead of going through a fuse block just wire it straight to the battery I havnt done any of this but I'm thinking of doing it this weekend may be it will help you

[QUOTE=MagikSmallie;531763]I just put a new Lowrance Elite HDI-Elite 7 on my 1990 Ranger 375V, I am having trouble with the transducer. It reads great when idling but as soon as I pick up speed and go to get on plane I lose signal. My boat won't really go that fast, only about 55 mph if I push it, so I don't think it's a speed problem. I've placed the transducer on the right side of the transom and just above the bottom of the boat. I can't figure out if I need to raise the transducer or lower it below the bottom of the boat, I want to figure it out without having to go through trial and error with drilling holes in my boat....any suggestions? The 1990 375V has two strakes on the bottom of the boat both left and right and my transducer is sitting above the right side strake, could this cause a problem?[/QUOTE]

Most likely the water coming off of that strake is what is causing the issue. But before I would go about drilling additional holes in your boat I would strongly recommend that you mount it inside of your hull.

I've seen this happen on several Lowrance models (mine included). I currently have an inside the hull mount and it's hit or miss on how it will read. Most of the time the transducer stops picking up around 20-25mph (sometimes a little faster, sometimes slower), but sometimes it just wont work with much speed at all. Maybe Lowrance could offer a suggestion for you or there's a pretty good forum for Lowrance issues on BBC. I've learned to live with mine for now.

[url]http://www.bbcboards.net/lowrance-garmin-sonar-gps/[/url]

I found this website and it looks promising. I'm going to try some of their suggestions and see where I end up

[QUOTE=MagikSmallie;531763]I just put a new Lowrance Elite HDI-Elite 7 on my 1990 Ranger 375V, I am having trouble with the transducer. It reads great when idling but as soon as I pick up speed and go to get on plane I lose signal. My boat won't really go that fast, only about 55 mph if I push it, so I don't think it's a speed problem. I've placed the transducer on the right side of the transom and just above the bottom of the boat. I can't figure out if I need to raise the transducer or lower it below the bottom of the boat, I want to figure it out without having to go through trial and error with drilling holes in my boat....any suggestions? The 1990 375V has two strakes on the bottom of the boat both left and right and my transducer is sitting above the right side strake, could this cause a problem?[/QUOTE]

Mount with an imaginary center line of the transducer below the boat transom. Also its recommended to mount the transducer on the left side to avoid water turbulence caused by the prop rotating to the right.

[QUOTE=MagikSmallie;531772]I found this website and it looks promising. I'm going to try some of their suggestions and see where I end up[/QUOTE]

[url]http://www.sternmate.com/Where.html[/url]

[QUOTE=rustedhook;531777]Mount with an imaginary center line of the transducer below the boat transom. Also its recommended to mount the transducer on the left side to avoid water turbulence caused by the prop rotating to the right.[/QUOTE]

That's funny you mention the left side because the lowrance installation guide said to mount on the right side of the motor to avoid the prop turbulence. It said most props will rotate that way when going forward...:confused:

I find it's the angle it's mounted at.

I copied the below instructions from Raymarine. According to them the transducer should be a little [B]below[/B] the hull. We have three transducers on our boat, one on the transom for a driver's fish finder, one shooting through the hull for a in dash flasher and one on the trolling motor. All work very well.


[h=2]Transom Mount Transducers[/h]
As the name implies, transom mount transducers are installed on the boat's transom, directly in the water and typically sticking a little below the hull. Transom mounts are composed of plastic and tend to be less expensive than other transducers.

Transom mount transducers are recommended for planing hulls of less than 27 feet (8 meters), such as personal watercraft and powerboats with outboard, inboard-outboard and jet drives. They are not recommended for large or twin screw inboard boats because aerated water from the propeller reduces performance. They are also not recommended for operation at very high speeds.

Transom mounts adjust to transom angles from 3° – 16°. For angles greater than 16°, a tapered plastic, wood or metal shim will be needed. However, the transducer should be adjusted so it is angled slightly forward when the boat is in the water.

Keep in mind some boats are quite a different angle
when running verses just sitting still.
I took my transducer and mounted it inside my aluminum boat
by squishing it into a dab of silicone sealer on the bottom.
Seems to work fine.

I'm going to make some adjustments and if all else fails I will just do a through the hull mount. thanks everyone for the input! I will get it working!!! seeing my running depth is very important to me.