997 losing bottom

[mark poulson]

I have an original 997 C unit, with a transom mounted transducer.
I've always been able to read depth even when on plane at 42mph.
I just started losing bottom when I get past 25mph.
It will read fine when I first get on plane, but then, once I get past 25, it will read fine for a few seconds, and then it drops to reading 3.9 feet until I come off plane again.
What caused the change?

[scottsweet]

Hi Mark,

Give me a call and maybe we can figure it out.

[mark poulson]

P.M. sent.

[mark poulson]

Hi Mark,

Give me a call and maybe we can figure it out.

Scott, I only have your old (818) number.
PM me with your current number.

[scottsweet]

Same number...8184483366.

Sorry for the delay...missed this.

[mark poulson]

Thanks. I actually think I got it solved. I siliconed the transducer on the transom so it can't vibrate, and that seems to have solved it.