Marine: Boating, Sailing, PWC, GPS and Navigation - Humminbird 525 Fishfinder

I just bought the 525 fishfinder and installed it along with the paddlewheel speed senser. The fishfinder seemed to work fine accept while i was motoring. I dont expect it to read the bottom and locate fish at 50 mph, but i sure would think that it would read the depth. While motoring it would only read 2-3 foot. Is this normal? Also the speed would only read about 6-10mph. I am running a 95' Procraft 210 dual pro. The transom does have 2 offset steps. The bottom most step is where the drain plug is at. The next step has my 2 livewell syphons and this is where i mounted the transducer and the paddlewheel and the next step is where the motor is located. Would it work better to move the paddlewheel down to that first step?

I'm not familiar with the hull design of your boat but the transducer and paddlel wheel should be mounted on the bottom of the hull. When your boat is on plane the water forms a sraight line off the bottom, and if there is a step water will hit the sensers at low speed but not on plane.