of the lateral portions 32 of the retaining lip are disposed with respect to the mounting flange 28 and transom face 24 each lip portion 31 and 32 defines a generally v shaped groove into which the edges of the clamping pads 23 will slide if the transom bracket assembly is displaced from its normal clamped position thus the retaining lip 30 not only provides a barrier to limit lateral and or vertical movement of the motor but displacement of the edges of the clamping pads 23 into the v shaped grooves 38 will tend to prevent the clamping assembly from overriding the retainer in order that the outboard motor 10 may be readily mounted to and demounted from the transom with the retainer attached thereto in its operative position the edge 37 of the retaining lip 30 must be disposed at a distance from the inside face 24 of the transom less than the distance between the face 24 and the clamping faces of the clamping pads 23 when the pads are fully withdrawn from clamping engagement thus use of the retainer of the present invention does not inhibit or impede the usual mounting or removal of an outboard motor except to require that the clamping thumb screws be substantially open to clear the edge 37 of the retaining lip 30 the outboard motor retainer of the present invention has been found to be most effective in preventing the motor from sliding laterally and or tilting up and off the boat transom under virtually all operating conditions including those where the thumb screws are left untightened one exception however may occur in a situation where the thumb screws are fully open completely withdrawn and the boat is operated in.