An electric outboard motor transom clamping system with two spaced apart side plates pivotally connected by at least one main pivot bolt or pin. Each side plate includes a clamp configured to press against the transom and hold the side plate in a rearward extending fixed position. Each slide plate also includes a ratchet slot located below the main bolt and a plurality of downward oriented pin slots transversely aligned the pins slots on the opposite side plate. Each pin slot is angled upward and rearward between 5 and 25 degrees from the center axis to a line that extends from the bottom of each pin slot to the main pivot bolt. A block member with two longitudinally aligned pins extend into the two ratchet slots. The pins engage the pin slots on the two side plates and hold the block member in fixed position between the two side plates.