Specifications

For 2-stroke motors 7 1/2 - 20 HP
Material: Anodised aluminium construction,
solid polypropylene mounting board
Board area: 260 x 205mm (10-1/4" x 8") Mount area on boat: 135 x 230mm (5-1/4" x 9")
Mount holes: 8mm
Lift range: 340mm (13-3/8")
Mounting holes have a horizontal distance of 100mm across (centre to centre), and multiple vertical holes for different mounting options

It's easy measure the depth from the top rail on the stern to where your prop would be nust below the bottom of the boat. On the floor mount your motor to your new auxiliary mount. Measure from the top of the prop to see what the difference is. Then mount the mount onto the transom so the prop is just below the hull when the aux mount is in the down position. Use 3m 4400 under mount and in the holes for the mounting bolts to seal it hang your motor and move it up and down to make shore its not in a bind.