The side imaging transducer has to be free of anything to the sides of the transducer if the motor or anything else is in it's line of sight to the sides it will not shoot through it to see anything on that side. You can use a transducer mounting board to keep from drilling a bunch of holes. Some of them require drilling a couple of holes and some of them just glue to the transom. I also found this it may help. Mounting transducer on a tr186 - Unofficial Humminbird Side Image Forums www.sideimageforums.com