If you stay about 1 foot away from the motor you should be fine for most sonar operation. Make sure you don't have a strake or a line of rivets that runs the length of the boat directly in front of the transducer as that will make turbulence, , transducers don't like turbulence.
I have a Humminbird Helix 10 with side scan, , I believe she'll go up to 200 feet out each side of the boat. Anyway, the transducer on that is something like 3" wide by 4" long. Not sure if that's any smaller than the one you have or not, , might be worth a look.
Something to be aware of, , , doesn't matter what side of the motor you put your transducer on, but for example, as you look at the back of the boat, if you install the transducer on the right side of the motor, you likely will get very limited or no left looking side scan as your transducer will be located very close to the motor and the motor will block the view. To get around this you will need to tilt the motor.
I have an inboard outboard, my transducer is on the right side of the drive approximately 24 inches away from the drive and I get limited left looking side imagine. If I raise the drive a little, no problem.
