Topic: Help Installing 998C in a Lund 1700

[MTBob]

Hi Folks:
This is my first post on this forum and I'm looking some help.  I've just purchased a HB 998C and I've got a bunch of questions about installation on my 2001 Lund 1700 Fisherman.  Let me start by asking your input on location of the transducers.  I have read most every post on this forum about transducer installation (and many other web references as well).  None of the posts I've seen quite address my concerns. 
First, here's a rear end photo of my boat.  I have a 115HP & 9.9 Merc, the kicker on the starboard side.  I am replacing the Lowrance X71 fish finder with the 998.  The transducer and wheel you see between the engines is for the Lowrance.






From what I've read, I will likely want to mount the 998 transducers on the Port side, about 15 inches left of the main engine. And, I also understand that the puck transducer needs full clearance left to right at it's "line of sight". 
Here's the concern I have:
- This transducer is huge, it is 6" long, not counting any supplemental mounting board.
- The 115 Merc lower end (the main lower end casing) - when fully trimmed down - sets about 4 1/2 " from the transom
- And the lower end splash guard protrudes forward about 2"


- In order to get clearance to the lower end casing I need to trim the engine up about 50% of it's high speed normal planning position
- But, there's more.  I also have a water inlet screen to the live well that is mounted at the lowest part of the transom.  It protrudes out about  1 1/2"
Here are more photos of the clearances:

I will remove the Lowrance transducer and wheel. (though I've considered keeping the X71 and moving these items to a new location).


So, with the engine trimmed out about 50% the clearance to the lower end is about 7".  But, the inlet screen is below the "eye level" of the 998 transducer.  I am probably going to use a plastic mounting plate for the transducers.  That means the overall length of the transducer will be about 6 1/2" +/-.


Here are my questions:
- Will the transducer work with the water inlet screen located as shown - protruding aft about 1" +/-?  I can probably jigger up some kind of screen thing that reduces the depth of the screen to about 1- 1 1/2". 
- Is it "normal" to have to trim out the engine to get clearance from the lower end when using the DI/SI system?
- Will the lower end splash guard (that sticks forward from the low end) interfere with the transducer?

[Trytoofish]

Im not sure because its hard to see in the picture but on my lund I think i have my transducer lower in the water or I loose depth at higher speeds. that helps with the intake screen also

[MTBob]

To clarify - the transducer you see between the engines in the photo are for my Lowrance X71.  I have not yet installed the 998C transducers.

[Humminbird_Greg]

On boats where the motor sits closer to the transom of the boat it is normal to have to trim out/up the motor so it does not block any of the Si sonar.
I think that the splash guard on the transducer will be too high and behind the transducer to cause a problem.
The water inlet screen will probably cause some Si sonar blockage.

You might want to consider installing the HDSi transducer on the right side of the motor about where the transducer is shown in the pictures now, though I am not sure what sort of clearance you have with your kicker motor or if you use it to back-troll with or not.


Trytoofish, post some pics of where you have your Si transducer installed for MTBob please.

[Trytoofish]

On my boat I have a transom saver board and a transducer saver bracket.that sets my transducer about 1.5 inches behind the transom. in this pic i'm leaveling the transducer. after I get it level with it hull i tip the front a hair up. also the final position it about 1/2 to 3.4 inch lower if you want high speed depth reading. my boat is still in storage I wish it wasnt. I had this pic on my computer. I do highly recomend the transom board and the transducer saver bracket. Mine is mounted in the same area where your lowrance on is.

[MTBob]

Thanks Greg & TryTooFish - Very helpful.  I can adjust the trim on my kicker to stay out from the transom a sufficient distance to not interfere with the Si transducer.  I do not back troll.   As far as keeping the 115 trimmed out, like you said, I don't think that should be a problem.  The only time it needs to be trimmed down is when I'm powering out of the hole and getting to a plane.
A few more questions:
TryTooFish: How thick of a transom board did you use?  I see other mounting holes in the board, are those from mounting the Si transducer, or other transducers?
Greg: - What portion of the transducer actually generates a signal?  Is the signal generated right at the forward leading edge of the puck, or at some place farther back?
Would you recommend that I mount the transducers to the right or left of my 115 HP engine? (I also purchased the Transom Transducer XNT 9 20 T at the recommendation of HB Technical Support).

[Humminbird_Greg]

MTBob,
I think that installing the HDSi transducer closer to the water inlet screen would be better in this case and since you are using a second transducer for high-speed depth readings you can move the HDSi transducer upwards a little bit too (not too high though or you will have to trim the motors up even higher).

Went back and took some quick measurements from an HDSi transducer they were building: the Si signal should start at about 1/2 inch from each end of the transducer.

[Trytoofish]

the board is 3/4 thick and roughly 4x12. any marine store or cabelas type store should have them. they are actually a poly type board so no rotting. the other holes are from a speed sensor and a past unit

here is a link for the transducer saver bracket

http://www.transducershieldandsaver.com/home/latest-products?page=shop.product_details&flypage=flypage.tpl&product_id=32&category_id=10

[MTBob]

Thanks TryTooFish & Greg, great comments:
I took a look at the Transducer Saver website and found "Due to popular demand, this item is temporarily out of stock.  Please contact us if you would like to be added to our Back Order list!"  $70.  I see how this thing works, looks like its a spring action.  What is puzzling to me is the mounting plate that comes with the HBSi transducer has a stainless steel mounting bracket that could have housed the same kind of spring mechanism.  But, instead it has rather significant indent on each side of the mounting that apparently is supposed to act as a snap release.  I've tried to move the transducer through this indent and it is really really strong - so much so, that if the transducer hit something it seems like it would destroy it. 
What do you guys think about this approach to mounting the transducer? >>  http://forums.sideimagingsoft.com/index.php?topic=3067.msg17714#msg17714 

[Trytoofish]

I have not seen them. the one i use also has a plastic flap the eliminates the rooster tail some boats get from the transducer. perhaps you could ask him how long the back order is going to be. I would think he would want them in stock soon.