Topic: 598ci si hd high speed

[jr0746]

Well I ended up having to replace my head unit to get di and si to work after 2 new transducer's now that I have that straight it won't read depth at high speed (on plane). I've read different postings but wanted an opinion on my boat. It's a Lowe roughneck 1860. I've got the ducer mounted on the factory mounting bracket. Should I really have to buy another ducer to read depth? I lowered it at least an inch below the bottom of the boat and it still would not read and it thru a rooster tail. Hopefully someone can give me some advice on what to do. This has been a headache

[LocDown]

SI transducers do not work well when trying to get bottom depth going above 7-10mph. If your boat is aluminum, you might have to get an alumaducer. You get your bottom depth reading from the 2d portion of the  transducer and you will need a Y splitter cable to hook up the SI and 2d transducers.

[jr0746]

So what kind of 2d ducer do I need to get to work with my 598ci?

[Humminbird_Greg]

Looks like you have an aluminum boat.  These are notorious for not being able to get a high-speed depth readings on or at least it is hard to do so.

First thing I would do is try lowering the backend of the transducer down just a little bit and see if that helps.

Next I would see if the area you have the transducer mounted at looks to have the cleanest (air bubble and turbulent water free) water flowing off of it.  If it does you should try making small adjustments to the running height of the transducer.  Sometimes too low is just as bad as too high.

Some have had good results from adding some type of spacer material between the transducer and the transom of the boat.  This may get the transducer pushed farther back from the transom and into cleaner water.

[jr0746]

The bracket that is factory on the boat sits 2" off the back of the transom. I have raised it, lowered it, put it where I thought it was split half way and same thing. When u say tilt the ducer down do you mean the end where the cord comes out or the end where it mounts to the bracket? Won't tilting the ducer throw off the DI?

[newkid4si]

jr0746
   By backend of the transducer, Greg is referring to the end farthest from the transom.
   I have an aluminum boat and also had the same experience with 2D at speed.
   With the transducer mounted so it was level with the bottom of the boat, top 2D speed was 7-8mph.
   By lowering the back as Greg suggested, I'm reading 2D bottom at 20mph now. That's my top speed.
   My guess without looking is that I lowered the back about 1/4".  Your adjustment may vary.
   My DI has not been affected by the change.

        Mike

     

[jr0746]

Thanks for all your input. I will try the changed first chance I get and let you know what I find. Thanks again

[Humminbird_Greg]

+1 to what Mike stated above.

I did not know that the bracket already held the transducer so far back off the transom.  Any chance that you could post some pictures of this and of the overall transom area of your Roughneck?