Patent ID: 6027385
Filing Date: 2000-02-22
Classification: B63H,F01M,F01N,F01P,F02B

Abstract:
A four cycle outboard motor comprised of a power head, an exhaust guide supporting at least in part a four cycle internal combustion engine in said power head, said exhaust guide being supported at the upper end of a drive shaft housing and lower unit that depend from said power head, a drive shaft driven by said engine and journaled within said drive shaft housing and lower unit for driving a propulsion unit therein for propelling an associated watercraft through a body of water, an oil pan is supported at least in part on the underside of said exhaust guide within the drive shaft housing and lower unit for containing lubricant for said engine, said oil pan defining an internal cavity passing vertically therethrough, and an exhaust pipe depending from said exhaust guide and extending through said oil pan internal cavity for receiving exhaust gases from said engine and for delivering them to said drive shaft housing and lower unit, said exhaust pipe having an upper portion communicating with said exhaust guide for receiving exhaust gasses passing therethrough and having a first diameter and an extension portion depending from the lower end of said upper portion, an air gap formed between said upper portion and said larger diameter extension portion to provide a suction break, said exhaust pipe terminating at a point that is no lower than substantially the lower surface of the oil pan.