Transducer problem?

[Pat Ling]

I just had a humminbird 788ci installed on my 2005 Nitro 911 and the unit works great EXCEPT as soon as I'm on plane with speeds of 30mph or so I loose my depth reading. I had it professionally installed and all other options are working properly. The transducer seems to be installed where recommended. Any suggestion or does anyone have a pic of their 911 showing transducer location. Thanks Pat

 

[Scott Hammer TOXIC]

Through hull or Transom mount?



TOXIC

 

[Pat Ling]

It's a transom mount, Toxic

 

[Scott Hammer TOXIC]

I figured, I have the same problem. I am going to move mine into the hull. I mounted exactly where I was supposed to and cannot get enough clean water to get a reading on plane but it does great if I am putting around.



TOXIC

 

[Humminbird Greg]

In general: on fiberglass boats you will get the best high-speed depth readings from a transducer mounted inside-the-hull in the bilge area as this is the lowest part of the hull and therefore the last part of the boat to leave the water. Less turbulent water there as well. A marina that is well versed in transducer installations should have communicated this to you before installing a transducer on the transom.





Greg Walters at Humminbird

 

[Pat Ling]

Can I use the same transducer to install in the bilge area that I used on the transom? or Do I need a new transducer. Like Toxic my unit works great puttin around and graphing an area.

 

[david Wickenheiser]

Hi

I think I heard that they make one for inside your boat that works with the side imaging one. The side imaging one needs to be on the back outside the boat It is made for slow speeds. the other one is made for fast speeds. They plug in the same line and when the slow speed loses contact the high speed one takes over (might work off gps?). I think I heard this at a side imaging seminar I went to in Pa. Me I have lowrance for the depth and Humminbird for the side imaging. Best of both worlds.

 

[Mini]

I respectfully disagree with Glenn especially on fiberglass boats.



a transducer that is epoxied in the hull is more prone to air bubbles. sonar does not work through air.



a clean install on the inside should get you speed reading IF (not a BIG IF) all of these conditions are met:



1. the area in the hull and through the glass has no gaps, air bubbles, voids, etc.



2. the epoxy used is also free of air bubbles



3. the face of the transducer is completely covered with epoxy



a transom mount needs these:



1. a position low enough in the water to get a good flow of "clean" water at speed



BUT if you live in stump infested waters you will want it inside the hull.



I dont, so I do not want ANYTHING but water on the face of the transducer. Beeter signal strength, less interference and NOTHING to get in the way.



I am wondering if your transducer is mounted on the lowest part of the hull....not near the motor, but near the drain plug.

 

[TritonGlenn]

Mini,

It wasn't Glenn that posted that (I'm Lowrance ). It was Greg from Humminbird. But I have to agree with my counterpart's assessment that the best high speed reading in a fiberglass boat will be found by using a transducer mounted in the bilge area.



The only other suggestion I would have to get the absolute best reading is something that makes most bass boat owners cringe, although I've installed them myself, and they work fantastic. A "thru hull" mount (not shoot-thru... I'm talking actual "thru hull mounted"). I had one on my Cajun Pro 178 and it gave fantastic readings. I couldn't use a shoot-thru on that particular boat because Cajun laid this metal mesh in their hull for strength. That metal mesh would cause all kinds of problems for shoot-thru. There was a hole drilled straight through the hull. Then the edges on the exposed bottom were countersunk for the transducer lip. The transducer slid through the hole on the bottom until the lip was flush with the hull. Lots of sealant around the whole thing. Then, inside the boat, a ring screwed down on the transducer, effectively "sandwiching" the hull between the top and bottom "lips" of the transducer body. It was the best of both worlds - no hull to shoot through, and no transducer to knock off with stumps, etc... (because it was flush). They are available if you want to check them out. Look at the P319 Thru-Hull here (item number 136-2):



All the best,

Glenn
http://www.lei-extras.com/store/search.asp?SearchType=Category&Category=Dual+Frequency+Transducer

 

[TritonGlenn]

By the way, on Epoxy, there are some rules you need to follow.



1) Clean and prep the area. When you think it's perfect, do it again.



2) Stir the epoxy with a smooth metal object. NEVER use a "stir stick". I've seen so many people use those wooden popsicle sticks, and they ALWAYS get bubbles. Why? Because the epoxy is heating up, and as that wooden stick (with all its pores) gets swished around in the mix, it releases little bubbles into it. Tons of them. Use a metal stick - think "nail".



3) The face of the transducer as well as the prepped area need to be completely covered with epoxy. Remember - Wet to Wet. Never put a wet epoxy covered item onto a completely dry item. Wet them both. When you put the wetted areas together, it results in much fewer incidences of bubbles.



4) Sufficient pressure must be kept on the transducer while letting it dry. Allowing it to just barely come up at any stage during the curing process WILL allow air bubbles to form - almost guaranteed. Have your "weight" ready so that the minute the surfaces are pressed together, the weight goes on and stays there until it's completely cured.



All the best,

Glenn

 

[Scott Hammer TOXIC]

It is more important to me to have a depth reading on plane than it is while putting around since I use it in conjunction with my GPS. When fishing the puck on my TM is the important one and it is fine. I worked my arse off putting this transducer on according to the instructions and it still won't read. BTW Mini, they do not recommend putting it down by the drain plug. That's where I thought it should go but they (Lowrance) say it needs to be on the first step of the hull off-center of the LU. I put it exactly where they said (they even included drawings for idjuts like me)and even went a little lower on the hull and it still won't read. I'll leave the bracket and just re-mount in the hull which, as Glenn so aptly pointed out requires a lot more work!! Ughhhhh.....



TOXIC

 

[Humminbird Greg]

Pat,

You can use a transom mount transducer as an inside-the-hull transducer. The only issue with this would be that we have built-in temperature sensors in most of our transom transducers so any temp reading would be from inside the hull and not the water temperature (though they could be the same). A better option (though it will require added expense) is to purchase an XP-9-20-T inside-the-hull transducer. This goes inside-the-hull and has a temperature sensor on the end of a ten foot cable that comes out of the transducer itself.



Like Glenn said: it takes some prep work and the devil is in the details when installing an inside-the-hull transducer. For me it isn

 

[Jim clear]

I just installed a 587ci on my 2005 nitro nx882. I dont know if the hulls are the same or not, but I found the best spot to be rght in front of the bulge pump off center about 1 inch. There is a stringer that runs right down the mddle. I used the expoxy that came wth the shoot thru the hull transducer, followed directions, tested it and found this spot. Have no problems at all, works wonderfully at any speeds. Temp probe mounted 1/4" from bottom of transom on outside next to jackplate mount. You have to assume that you will loose 15 to 20% sensitivity but that is ok since the trolling motor transducer is what I use mainly to spot fish. Works great.

 

[Mini]

Sorry Glenn, I was tired and skimmed the names , Greg W I will agree to disagree too BUT I will agree what you said about starving the lower unit. Mine has low water pickups so its not an issue!



I didnt mean AT the drain plug Toxic! Mine is on the same section of the hull to the right of the drain plug. I have had numerous Nitros and all were mounted in the same area. All were low enough to get a great flow of water and I get readings over 60mph on flat water. My Ranger is no different.



I will add that I have mounted ALL of my transom mount transducers myself. If one was mounted inside the hull, it came from the factory and it was for a flasher that was included in he base price of the hull.



I dont care what anyone says I agree with Jim, you WILL lose 15-20% sensitivity by mounting it inside the hull.



I just want the strongest signals I can get....again, I fish open water. If I were fishing in the south I would epoxy everyone in.

 

[Pat Ling]

I recieved an email from Humminbird telling me to tilt the transducer an extra 7%. I'm not sure if they want it tilled from back to front or front to back. Anyone have an idea?

 

[Humminbird Greg]

You need to tilt the back end down. This sometimes help direct the upper layer of water that has the air bubbles in it around the transducer instead of under it (where it keeps the transducer from reading).





Greg Walters at Humminbird