Finder not working at higher speeds

brushpile · #1 06-26-2006, 06:59 AM

I just installed a Lowrance 135 on my boat. I decided to go ahead and drill into the transom for the transducer mount. No leaks, but I have a problem. I get a great picture on my screen while cruising, but when I'm at full speed (about 40 mph) the sonar will not pick up the bottom. It will either flash or give a totally inaccurate depth reading.

The directions stated that you should mount it in between the ribs closest to the engine on an aluminm boat, but you should maintain at least 1 foot from the lower unit. I mounted my transducer about 13 inches from the lower unit.

Do I need to remount the transducer over a little farther away from the engine? If I do this, how should I fill the 2 holes at the bottom of my transom?

Thanks,

catseeman · #2 06-26-2006, 08:24 AM

Moving it over will probably help. Prop wash or air bubbles seem to effect mine. When on plane my transducer is just barely in the water.

FishMan · #3 06-26-2006, 08:41 AM

mine works good at hi speeds but it doesn't help me. no matter how much I practice I just can't get that cast right when going 40 MPH. I even slowed down to 30 in case the fish were having a hard time keeping up but still, no bites.

Good Morning

loanwizard · #4 06-26-2006, 08:46 AM

I have the same problem with my Jet Drive. I would check to see if the transducer is low enough. The midline of the transducer should be level with the bottom of the boat. I have a 135 too.

catfishrus · #5 06-26-2006, 09:05 AM

drop your tranducer down. its coming out of the water at high speed or catching air making lose contact with the water. also make sure its shooting straight down when the boat is in the water. i notice some folks set theirs according to the bottom of the boat but most boats set up in the front a little in the water.