Abstract: A cowling assembly for an outboard motor includes an improved construction that can supply relatively cool air containing little if no water to the induction device and that can also supply air to cool engine components without reducing the charging efficiency. The outboard motor has an engine that includes an air induction device and is enclosed by the cowling. The induction device has an air inlet opening. The cowling assembly defines a closed cavity in which the engine is contained and has an air intake duct that introduces air into the cavity. The intake duct adjoins the inlet opening and has an opening opened to the cavity and positioned lower than a lower end of the inlet opening. In one form, the cowling assembly has at least one front air intake opening formed on a side surface of its front portion. A rear air intake opening is also formed on a rear surface of its rear end portion.

Abstract: A four stroke engine having at least two cylinders spaced vertically relative to each other. Each cylinder includes a cylinder body having a cylinder bore extending generally horizontally. Plurality of air intake ducts are provided for connecting a common plenum chamber and respective air intake passages which extends to respective combustion chambers. Each of the air intake ducts has a generally straight section extending generally horizontally and parallel to each other. The distance between the straight sections is less than the distance between the axes of the cylinder bores. Also, in another feature, throttle body means are interposed between duct members, which are upstream components of the air intake ducts, and the intake passages for controlling the flow of air to the combustion chambers.

Abstract: An outboard motor has an induction system and a fuel supply system. The two systems are linked together to improve responsiveness of the fuel supply system based upon fluctuations in pressure within the induction system. The motor includes an induction air pressure detection system. The detection system comprises a pressure sensor and a connection to at least two different air intake pipes of the induction system. The connection between the sensor and the two pipes is configured such that the distance between the sensor and each of the pipes is the same. The detection system is configured to sample the pressure in multiple intake pipes associated with multiple cylinders using connecting conduits that have the same length from each intake pipe to the pressure sensor.

Abstract: A blow-by gas ventilation system for a crankcase of an engine includes an improved construction for distributing blow-by gases more evenly between multiple cylinders. The engine has an air intake device that includes a plurality of air delivery conduits for the cylinders and a plenum chamber housing disposed upstream of the air delivery conduits. The ventilation system comprises a blow-by gas conduit that couples the crankcase with the plenum chamber housing. The plenum chamber housing includes an opening to which the blow-by gas conduit is connected. A baffle is disposed in front of the opening within the plenum chamber housing so as to divide the blow-by gases equally for the respective cylinders.

Abstract: A four cycle outboard motor that have water cooled engines and an oil pan that is formed in the upper portion of the drive shaft housing. An exhaust pipe collects exhaust gases from an exhaust guide and delivers to a cavity that is formed in the oil pan by an interior wall thereof. The exhaust pipe does not terminate below the lower surface of the oil pan and idle exhaust gases are delivered to the area between the exterior of the exhaust pipe and the interior surface of the oil pan that defines the cavity. These idle exhaust gases are discharged to the atmosphere through and above the water exhaust gas discharge. The oil pan lower surface has a drain opening that is aligned with a vertical drain opening in the drive shaft housing.

Abstract: A number of embodiments of four cycle outboard motors that have water cooled engines and an oil pan that is formed in the upper portion of the drive shaft housing. An exhaust pipe collects exhaust gases from an exhaust guide and delivers to a cavity that is formed in the oil pan by an interior wall thereof In many embodiments the exhaust pipe does not terminate below the lower surface of the oil pan and several arrangements are disclosed for delivering idle exhaust gases to the area between the exterior of the exhaust pipe and the interior surface of the oil pan that defines the cavity. Various arrangements are disclosed for conveying idle exhaust gases to this area and discharging them to the atmosphere through and above the water exhaust gas discharge. These arrangements incorporate a system for precluding water from entering into the engine through its exhaust system including the idle discharge.

Abstract: A cowling arrangement for an outboard motor for use in powering a watercraft is disclosed. The motor has an engine and a water propulsion device, the engine having an output shaft arranged to drive the water propulsion device. The engine has a body with a top end and a bottom end, the output shaft extending above the top end. A flywheel is connected to the output shaft at the top end of the engine, and a flywheel cover is positioned over the flywheel and supported by the engine body. The cowling defines an engine compartment in which the engine is positioned and has an opening therein. A starter panel is connected to the flywheel and supported solely thereby, the starter panel cooperating with the cowling to close the opening therein, the starter panel supporting at least one component of a starter for the engine.

Abstract: A four cycle outboard motors that have water cooled engines and an oil pan that is formed in the upper portion of the drive shaft housing. An exhaust pipe collects exhaust gases from an exhaust guide and delivers to a cavity that is formed in the oil pan by an interior wall thereof. The exhaust pipe does not terminate below the lower surface of the oil pan and idle exhaust gases are delivered to the area between the exterior of the exhaust pipe and the interior surface of the oil pan that defines the cavity. These idle exhaust gases are discharged to the atmosphere through and above the water exhaust gas discharge. The oil pan lower surface has a drain opening that is aligned with a vertical drain opening in the drive shaft housing. At least a pair of elastomeric members are clamped between the drive shaft housing and the oil pan to provide stiffness and sound damping.

Abstract: A number of embodiments of four cycle outboard motors that have water cooled engines and an oil pan that is formed in the upper portion of the drive shaft housing. An exhaust pipe collects exhaust gases from an exhaust guide and delivers to a cavity that is formed in the oil pan by an interior wall thereof. The exhaust pipe does not terminate below the lower surface of the oil pan and several arrangements are disclosed for delivering idle exhaust gases to the area between the exterior of the exhaust pipe and the interior surface of the oil pan that defines the cavity. Various arrangements are disclosed for conveying idle exhaust gases to this area and discharging them to the atmosphere through and above the water exhaust gas discharge. These arrangements incorporate a system for precluding water from entering into the engine through its exhaust system including the idle discharge.