Patent ID: 6044828
Filing Date: 2000-04-04
Classification: F01M,F02B

Abstract:
An outboard motor comprised of a power head having a powering internal combustion engine and a surrounding protective cowling, a drive shaft housing lower unit depending from said power head and journalling a drive shaft, a watercraft propulsion device and a transmission for driving the watercraft propulsion device from the drive shaft for powering an associated watercraft contained within said lower unit, said engine being mounted in said power head so that an engine crankshaft rotates about a vertically extending axis within a crankcase chamber of said engine, said crankcase chamber being formed at one end of a horizontally extending cylinder bore, said crankcase chamber defining an oil collecting area for containing oil, a cylinder head assembly closing the other end of said cylinder bore, a valve actuating mechanism contained within a valve chamber formed in said cylinder head for operating valves contained therein and which control the admission of a charge to said cylinder bore and the discharge of burnt combustion products from said cylinder bore, a slinger mechanism driven by said crankshaft for throwing oil contained in said oil collecting area of said crankcase chamber, an oil path arrangement for permitting oil thrown by said slinger mechanism to flow to said valve chamber and drain back from said valve chamber to said crankcase chamber, a crankcase ventilating conduit extending from an upper area of said crankcase chamber to an induction system that delivers at least an air charge to the combustion chamber so that crankcase ventilating gases will be returned to said cylinder bore for further combustion therein, and an oil separator positioned in said crankcase ventilating conduit externally of said engine and having an oil drain that drains oil back to said crankcase chamber.