Abstract: A locking device for an outboard motor having a C-shaped mounting bracket fitting over the back transom of a boat and containing a mounting screw with a handle at one end for tightening a foot at the other end against the transom, said locking device having a first member with two angular arms, one of which is secured against the transom by the foot of the mounting screw and the other arm locked to a second member having a handle restraining portion located adjacent the handle to prevent rotation of the handle.