Transducer installation

[Plugger]

Have recently installed a Garmin 140 on my alum. jon boat ( Tracker Grizzly ).  I installed in a 3/8" below transom and have readjusted it a little lower since.  It loses the bottom about 30% of the time ( loses it more on a right turn -transducer on left side ) .  I have the transducer level to ground while on trailer but boat runs with nose a little higher.  Any help on which way to start more adjustments would help a lot.   

Thanks,
Plugger

[-Bryan-]

Can you post a pic of where it is now?  That would be a huge help in getting you set up right.