Abstract: Disclosed herein is an outboard motor comprising a cylinder, a crankcase extending from the cylinder and including an upper portion having a bearing and a lower portion having a drainage outlet, a transfer passage extending between the cylinder and the crankcase, a drains return inlet in one of the cylinder and the transfer passage, a fuel supply system including an inlet manifold communicable with the cylinder and having a drains outlet and a carburetor communicating with the inlet manifold and having a drainage outlet, an overboard drain, and a valve and conduit system selectively operable for communicating the overboard drain with each of the manifold drains outlet, the crankcase drains outlet, and the carburetor drainage outlet, for communicating the crankcase bearing and the drains return inlet with the manifold drains outlet and the crankcase drains outlet, and for closing the carburetor drainage outlet.