Need help on new speed/temp transducer?

[Tracey]

Recently bought new lowrance X-75 and took it out for a test run and my speed on my sonar was 10 mile an hour faster than factory dashmount. Is it normal for them to be this far apart?? Will reajusting the speed cal take care of this or have I mounted it wrong?? My sonar also lost bottom contact at 25-30 mph? Is this also normal or am I geting airbubbles over transducer at this speed?? Transducer is mounted flush with bottom of boat. Any help will be appreciated.
Thanks Tracey

[Mr. Pike Ltd.]

My Eagle Optima, same as your x75, was 27% too fast. Adjust yours with a GPS, not the on board speedo, as they can be off a whole bunch too!!
As for losing the bottom, try moving the xducer down 1/4" at a time. Sounds like air bubbles or turbulence?? Report back?

[Mr. Pike Ltd.]

My Eagle Optima, same as your x75, was 27% too fast. Adjust yours with a GPS, not the on board speedo, as they can be off a whole bunch too!!
As for losing the bottom, try moving the xducer down 1/4" at a time. Sounds like air bubbles or turbulence?? Also, point the front of the xducer up a little bit. Report back??