Abstract: An outboard motor includes an improved engine layout to provide a compact power head while simplifying the arrangement of components on the engine. In one mode, an induction system of the engine includes a carburetor that is arranged over a cylinder head. An intake pipe connects the carburetor to an intake port of the cylinder head. The pipe has generally a U-shape and loops around the upper side edge of the cylinder head. An air intake device is arranged upstream of the carburetor to supply air thereto. The air intake device includes a downward facing air intake opening that is located along a side of the engine below the upper end. This arrangement of the induction system that extends over the upper side of the engine produces a compact assembly without overly complicating the arrangement of other components on the engine, such as, for example, a manual starter device.

Abstract: An improved and simplified outboard motor construction wherein the exhaust system for the engine is formed with a minimum number of components and sealing joints. The exhaust system includes an elongated expansion chamber formed in the drive shaft housing. In addition, the drive shaft housing has a cylindrical section that is journaled within a swivel bracket for its steering movement. The volume between the external portion of the drive shaft housing and the internal portion of the swivel bracket forms a second expansion chamber that is employed for the low speed above the water exhaust gas discharge. The flow of cooling the water to and from the engine is controlled so that the exhaust gas interchange area between the power head and the drive shaft housing will be well cooled, as will the oil reservoir for the engine.

Abstract: A protective cowling arrangement for an outboard motor that provides an atmospheric air inlet having a pair of openings disposed above the engine for permitting atmospheric air to flow into the protective cowling for engine combustion. One of these openings is disposed in part above components of the engine which should not be contacted by water and this opening is substantially smaller than the other opening. An engine cover is also affixed to the engine and obscures the smaller opening to afford further water protection.

Abstract: Two embodiments of protective cowling arrangements for outboard motors that provide a forwardly facing air inlet having a lower inlet atmospheric inlet opening which communicates with a higher atmospheric air passage that extends through the protective cowling to its interior. A plurality of horizontal baffles assist in water separation for the inducted air and additional air may be inducted through a rear air inlet opening in the protective cowling.