I have a 1997 200 pro vee with a hummingbird 1198 with a shoot through transducer. The transducer is back as far as I can get. It works fine when I am running below 35 mph but when I get past 35 it lose reading. Sometime it will read the depth say 80' but no 2d most of the time it reads 1.6'. I have put water in the sump but did not change. Do any of you Bee owners have this problem?