Abstract: Apparatus for simultaneously flushing multiple outboard boat motors, or for simultaneously flushing a boat motor and hosing down a boat, includes a water flow manifold having a single input conduit, which receives water from a single water source, and communicates the water to at least two output conduits of the manifold. A water flow control means interposed between the input conduit and the output conduits controls the relative flow of water to the output conduits. Flexible tubing attached to and extending from the output conduits communicates the relative water flow to a pair of tubing adapters, each having one end attached to the flexible tubing and an opposite end either attached to a motor flush port or, alternatively, to a conventional water hose nozzle.