Abstract: Combustion air intake ports are provided on left and right side faces of an upper part of an engine cover. An outer louver is disposed to confront the combustion air intake port, and an inner louver is disposed inward of the outer louver at a predetermined interval to face the outer louver. The combustion air received from the combustion air intake port passes through the outer louver and the inner louver and is guided to the engine unit from the guide hole. In this case, a splash of water is dispersed in the outer louver, and a large-sized water droplet falls down due to its self-weight before the combustion air reaches the inner louver, so that a small-sized water droplet can be collected and removed using inertial impaction at the inner louver. Therefore, it is possible to effectively separate water.

Abstract: Combustion air intake ports are provided on left and right side faces of an upper part of an engine cover. An outer louver is disposed to confront the combustion air intake port, and an inner louver is disposed inward of the outer louver at a predetermined interval to face the outer louver. The combustion air received from the combustion air intake port passes through the outer louver and the inner louver and is guided to the engine unit from the guide hole. In this case, a splash of water is dispersed in the outer louver, and a large-sized water droplet falls down due to its self-weight before the combustion air reaches the inner louver, so that a small-sized water droplet can be collected and removed using inertial impaction at the inner louver. Therefore, it is possible to effectively separate water.

Abstract: An exhaust structure for use in an outboard engine of a vertical-type four-cycle V-type having cylinder heads, a crankcase, cylinder blocks constituting left and right sides of an integral body disposed in a V shape as seen in a plan view and forming a V-bank therebetween, an intake system disposed in the V bank, exhaust systems disposed on the left and right sides outside the V-bank, and a crankshaft disposed substantially vertically to the surface formed where the crankcase and cylinder blocks join one another, wherein the engine is disposed above an engine support attached to the hull and an oil pan is disposed beneath the engine support. The exhaust systems join and become integral inside the engine support and then pass through the interior of the oil pan to discharge exhaust gases. The invention provides an outboard engine exhaust structure having a non-complex oil pan of sufficient capacity.

Abstract: An outboard motor includes a vertical multi-cylinder engine, a fly-wheel magneto device, a partition plate, and a ventilation fan. The vertical multi-cylinder engine is disposed in an engine cover and comprises a crank case and a crank shaft, the crank shaft being rotatably disposed and protruding upward from the crank case. The fly-wheel magneto device is disposed on the protruding portion of the crank shaft. The partition plate is disposed in the engine cover and partitions the inside of the engine cover into an engine air-inlet space and a space including a heat-generating source, the engine air-inlet space being disposed at the upper portion of the engine cover, and the space including a heat-generating source being disposed at the lower portion of the engine cover. The ventilation fan is disposed in the lower space below the partition plate.

Abstract: A lubricating system for an outboard motor equipped with a vertical type engine. In one embodiment, the lubricating system has an oil pump positioned near the bottom of the engine, the oil pump driven by an oil pump rotor that is positioned at a connection between the crankshaft and an engine drive-shaft, the oil pump rotor being linked to the crankshaft. The system further includes a camshaft-driving mechanism for transmitting the rotation of the crankshaft to a propulsion device. The camshaft-driving mechanism is also positioned at the connection between the crankshaft and the drive-shaft and is also linked to the crankshaft. The lubrication system also has a main oil tank for storing lubricating oil circulated by the oil pump, and an engine-cooling water passageway positioned next to the main oil tank. Another element of this embodiment of the lubricating system is a filter-mounting base positioned on an outer wall of the cylinder blocks.

Abstract: An outboard motor includes a vertical multi-cylinder engine, a fly-wheel magneto device, a partition plate, and a ventilation fan. The vertical multi-cylinder engine is disposed in an engine cover and comprises a crank case and a crank shaft, the crank shaft being rotatably disposed and protruding upward from the crank case. The fly-wheel magneto device is disposed on the protruding portion of the crank shaft. The partition plate is disposed in the engine cover and partitions the inside of the engine cover into an engine air-inlet space and a space including a heat-generating source, the engine air-inlet space being disposed at the upper portion of the engine cover, and the space including a heat-generating source being disposed at the lower portion of the engine cover. The ventilation fan is disposed in the lower space below the partition plate.

Abstract: An intake system of an outboard motor including a vertically arranged V-type engine comprises, an intake manifold connected to the intake ports, a surge tank connected to the intake manifold and disposed at a rear side from a central portion of the engine, a throttle body provided with a throttle valve, a plurality of intake passages for high revolution operation of the engine. The intake passages for high revolution operation extend from the surge tank and are communicated with the intake manifold, and the intake passages for low/intermediate revolution operation extend from the surge tank and are joined with the intake passages for high revolution operation, respectively. Each of the intake passages for low/intermediate revolution operation has a length longer than that for high revolution operation. A valve open/close mechanism is also disposed for opening/closing all at once portions upstream side of the joined portions of both the intake passages of the engine.

Abstract: An air intake cooling system for an outboard motor equipped with a V-type engine. In one embodiment, the air intake cooling system has an air intake manifold and a water-cooling passageway positioned in the air intake manifold for cooling air in the air intake manifold. The system further has a water sleeve for cooling a main oil reservoir located inside the V-type engine, the water sleeve positioned next to the main oil reservoir and connected to the water-cooling passageway. The system uses water in the water-cooling passageway for cooling the air intake manifold and in the water sleeve for cooling a lubricating oil in the main oil reservoir, the water used to cool the intake manifold being the same as the water in the water sleeve.

Abstract: A four-stroke-cycle engine of an outboard motor, comprises an engine body, a crankshaft, at least one camshaft, at least one camshaft driving mechanism, an oil pump, at least one valve timing adjusting mechanism and at least one valve timing controlling mechanism. The crankshaft and the camshaft are disposed in an upright state in the engine body. The camshaft driving mechanism transmits a rotational motion of the crankshaft to the camshaft. The camshaft driving mechanism is disposed on a lower side of an engine body. The oil pump for lubrication is disposed on the lower side of the engine body. Oil is supplied from the oil pump to the valve timing controlling mechanism to control the valve timing adjusting mechanism. The valve timing controlling mechanism is disposed on a lower side of an outer wall of a valve train chamber in which the camshaft is received.

Abstract: An air intake cooling system for an outboard motor equipped with a V-type engine. In one embodiment, the air intake cooling system has an air intake manifold and a water-cooling passageway positioned in the air intake manifold for cooling air in the air intake manifold. The system further has a water sleeve for cooling a main oil reservoir located inside the V-type engine, the water sleeve positioned next to the main oil reservoir and connected to the water-cooling passageway. The system uses water in the water-cooling passageway for cooling the air intake manifold and in the water sleeve for cooling a lubricating oil in the main oil reservoir, the water used to cool the intake manifold being the same as the water in the water sleeve.

Abstract: A lubricating system for an outboard motor equipped with a vertical type engine. In one embodiment, the lubricating system has an oil pump positioned near the bottom of the engine, the oil pump driven by an oil pump rotor that is positioned at a connection between the crankshaft and an engine drive-shaft, the oil pump rotor being linked to the crankshaft. The system further includes a camshaft-driving mechanism for transmitting the rotation of the crankshaft to a propulsion device. The camshaft-driving mechanism is also positioned at the connection between the crankshaft and the drive-shaft and is also linked to the crankshaft. The lubrication system also has a main oil tank for storing lubricating oil circulated by the oil pump, and an engine-cooling water passageway positioned next to the main oil tank. Another element of this embodiment of the lubricating system is a filter-mounting base positioned on an outer wall of the cylinder blocks.

Abstract: An exhaust structure for use in an outboard engine of a vertical-type four-cycle V-type having cylinder heads, a crankcase, cylinder blocks constituting left and right sides of an integral body disposed in a V shape as seen in a plan view and forming a V-bank therebetween, an intake system disposed in the V bank, exhaust systems disposed on the left and right sides outside the V-bank, and a crankshaft disposed substantially vertically to the surface formed where the crankcase and cylinder blocks join one another, wherein the engine is disposed above an engine support attached to the hull and an oil pan is disposed beneath the engine support. The exhaust systems join and become integral inside the engine support and then pass through the interior of the oil pan to discharge exhaust gases. The invention provides an outboard engine exhaust structure having a non-complex oil pan of sufficient capacity.

Abstract: A four-stroke-cycle engine of an outboard motor, comprises an engine body, a crankshaft, at least one camshaft, at least one camshaft driving mechanism, an oil pump, at least one valve timing adjusting mechanism and at least one valve timing controlling mechanism. The crankshaft and the camshaft are disposed in an upright state in the engine body. The camshaft driving mechanism transmits a rotational motion of the crankshaft to the camshaft. The camshaft driving mechanism is disposed on a lower side of an engine body. The oil pump for lubrication is disposed on the lower side of the engine body. Oil is supplied from the oil pump to the valve timing controlling mechanism to control the valve timing adjusting mechanism. The valve timing controlling mechanism is disposed on a lower side of an outer wall of a valve train chamber in which the camshaft is received.

Abstract: An intake system of an outboard motor including a vertically arranged V-type engine comprises, an intake manifold connected to the intake ports, a surge tank connected to the intake manifold and disposed at a rear side from a central portion of the engine, a throttle body provided with a throttle valve, a plurality of intake passages for high revolution operation of the engine. The intake passages for high revolution operation extend from the surge tank and are communicated with the intake manifold, and the intake passages for low/intermediate revolution operation extend from the surge tank and are joined with the intake passages for high revolution operation, respectively. Each of the intake passages for low/intermediate revolution operation has a length longer than that for high revolution operation. A valve open/close mechanism is also disposed for opening/closing all at once portions upstream side of the joined portions of both the intake passages of the engine.

Abstract: An outboard motor with an engine having a crankcase in which a crankshaft is perpendicularly arranged in a state that the outboard motor is mounted to a hull. The outboard motor is provided with a fuel supply apparatus that includes an interlocking mount member to be mounted to the engine, a plurality of air-fuel mixture supply devices mounted to the interlocking mount member, an intake noise silencer mounted to the air-fuel supply means, an engine starting operation assisting device for assisting smooth starting of an engine operation, and a speed reduction control device for preventing engine stall. The starting operation assisting device and the speed reduction control device are mounted to the interlocking mount member as one unit.

Abstract: A lubricating apparatus for an engine of an outboard motor comprises an oil pan disposed in a lower portion of an engine in a mounted state thereof and provided with an oil accumulating tank, an oil strainer for straining an oil accumulated in the oil accumulating tank, an oil pump for supplying strained oil to an inside portion of the engine, the oil strainer and the oil pump being mounted to a structural member such as pump case disposed above the oil pan so as to be connected to each other, and an oil suction pipe extending from the oil strainer to a bottom portion of the oil accumulating tank.

Abstract: In an outboard motor, a balancer shaft is arranged in a crank chamber substantially in parallel to a crank shaft disposed in an engine unit so as to extend perpendicularly in an operative state of an outboard motor and end portions of the balancer shaft are supported by bearings. The end portions of the crank shaft and the balancer shaft are covered and sealed by a seal member straddling over both the end portions thereof.

Abstract: An outboard motor has a structure in which a cam shaft is arranged substantially in parallel to a crank shaft disposed in an engine unit so as to perpendicularly extend in an operative state of an outboard motor and a fuel pump is disposed at a portion near an upper end portion of the cam shaft. A swash plate cam is disposed to an upper end of the cam shaft and the fuel pump is provided with a plunger having a projected end portion operatively contacting the swash plate cam to be reciprocally movable in a direction substantially parallel to an axis of the cam shaft when the swash plate cam is driven.