kicker interfereing with fishfinder?

[nanrabbott]

Hi, I am a new boat owner and installed a 1987 Mercury 9.9 kicker onto the transom of my 1989 17 foot Tracker ProV. Discovered that when running the kicker the fishfinder reports the depth accurately but sees no fish. As soon as we turn off the kicker and go back to running the 50 horse main motor we see lots of fish. From the bit of research I have done on this forum, it seems like turbulence from the prop of the kicker may be causing the problem. As I am not keen to drill more holes in the hull. Is there anything else I should be aware of before moving the transducer?

 

[fucawi]

Re: kicker interfereing with fishfinder?

Transucer should be on the right of the prop looking from the back (starboard) so if you have your kicker on the port side you should be ok...The bottom will give a stronger reflection than the fish

 

[Fed]

Re: kicker interfereing with fishfinder?

Maybe the 50HP is creating the fish, what do you see with no motors running?

 

[nanrabbott]

Re: kicker interfereing with fishfinder?

We are fishing Lake Ontario, leaving from Olcott NY and cruising north using the 50 HP motor until we see fish on the finder, usually beginning at 65 to 90 FOW then slow down to trolling speed to actually fish. This weekend the lake was calm so we trolled out to 300 FOW. I don't think the 50 horse is creating the fish but thanks for the suggestion. After finding the fish we were trolling east to west at 2+ mph, seeing lots of fish until we started up the 9.9, then the fish dissappeared, reappearing when we switched back to the 50 horse. Heading back to port. We again lost the fish in 65 FOW.

 

[fucawi]

Re: kicker interfereing with fishfinder?

but you have not told us what the arrangement of motors and transducer is on the back of the boat..there is also the potential for electrical interference. oh yes did you catch anything?

 

[nanrabbott]

Re: kicker interfereing with fishfinder?

Looking at the back of the boat from left to right are: a transducer, the 9.9 Mercury, the 50 horse Mercury (centered on the transom) and another transducer. What I can't tell you, or find out at this time (boat is at another home) is if the left transducer is in-line with the 9.9 mercury. I also can't tell you if the forward mounted fishfinder is having the same issues as we haven't used it on these outings. All stuff for me to check on and report back after our next outing. (it won't be this weekend as waves are predicted to be 11-15 ft) We caught a small rainbow trout and a small Coho salmon on this outing. We have had problems with the forward fishfinder giving us crazy depth readings, from reading elsewhere on the forum, it sounds like this would be caused by electrical interference.

 

[fucawi]

Re: kicker interfereing with fishfinder?

if I read it right you have the transducer on the port ( left ). It should be on the right (starboard) even if you only had one motor so its away from prop turbulance which differs on each side of the motor .... ....so now you know what to do ......get the shifters in

 

[Fed]

Re: kicker interfereing with fishfinder?

Get some pictures of the back of the boat nanrabbott.

 

[fucawi]

Re: kicker interfereing with fishfinder?

Does not matter about photos fred he has the transducer too close and on the port side of the kicker ..you cannot change the laws of physics....whats a couple of holes ..we will all have holes soon... worm holes ..life is too short just move the thing

 

[nanrabbott]

Re: kicker interfereing with fishfinder?

I'll post some pics this weekend. Can I have two transducers adjacent to each other? Will they not interfere? BTW, thank you for your good advice and suggestions.

 

[Fed]

Re: kicker interfereing with fishfinder?

I've had interference from nearby boats I think it has to do with the whether they are on the same frequency or not.

I have to disagree fucawi in my experience it makes no difference which side of the motor the transducer is mounted and proximity is only to do with disrupting the water flow to the prop rather than the prop causing interference with the transducer after all the transducer is forward of the prop.
I always mount them on the starboard side but I've seen plenty on the port side that seem to work fine.

I think you need to do some testing nanrabbott, stationary with all motors off, each sounder, both sounders, big motor in neutral, kicker in neutral, big motor in gear, kicker in gear, it goes on & on but I think that's the way to get to the bottom of it.
Positioning of the transducers is important so pics will really help.

 

[fucawi]

Re: kicker interfereing with fishfinder?

Well fred ..if you want the transducer to work when you are on the plane then you need the transducer nearer to the centre line or it lifts out the water . Its a proven fact that the right or starbard side is the prefered location .

Suggestion ..I dont know what your boat is made of but a shoot through transducer is one answer .. I have mounted external types inside the hull before using epoxy ( no air bubbles please ) and they work fine

 

[nanrabbott]

Re: kicker interfereing with fishfinder?

Get some pictures of the back of the boat nanrabbott.

Boat was wrapped up for a storm that was coming, but here are photos.