Abstract: Disclosed herein is a flushing device for supplying fluid to a water intake port on a lower unit of an outboard motor. The device comprises a flexible strap having a first end and a second end, along with a buckle connected to the first end. The buckle includes a kinked portion which has a cross member and which is adapted for engagement with the lower unit, which buckle also includes an over-the-center latch pivotally connected to the kinked portion. The buckle also includes a strap link connected to the first end of the strap and connected to the latch at a point radially outwardly spaced from the kinked portion pivotal connection with the latch. A cup-shaped member is connected to the strap and spaced from the buckle, which member is adapted for sealing engagement with the lower unit and for covering the water intake port. The cup-shaped member includes a conduit adapted for communication with the water intake port and with a source of fluid.