Abstract: An outboard motor has various electrical components mounted on a front side of the crankcase chamber. The crankcase chamber is connected by an electrical line to a negative terminal of a battery in an associated watercraft in order to ground the crankcase chamber. Thus, the electrical components are easily grounded by being connected to the crankcase chamber. An intake silencer of the engine induction system is positioned adjacent the crankcase chamber and at least one of the electrical components is disposed between the silencer and the crankcase member. An oil filter mount is also disposed on the front side of the crankcase chamber. The mount is adapted so that the oil filter can be installed thereon and is tilted along an inclined axis.

Abstract: An electrical system for a marine outboard drive includes an improved construction. The outboard drive includes an engine. The engine has a combustion chamber, a fuel supply unit arranged to supply fuel to the combustion chamber, and an igniting unit arranged to fire the fuel in the combustion chamber. The electrical system includes a power source arranged to supply electricity to the fuel supply unit and the igniting unit. The electrical system includes a first control device and a second control device. The first control device is arranged to control the fuel supply unit and the igniting unit while the second control device is arranged to watch the supply of electricity. The second control device is physically separated from the first control device.

Abstract: A component mounting arrangement for an engine includes an improved construction that can allow components such as a wire harness and/or fluid conduits to be neatly arranged around the engine. The engine includes a valve actuation mechanism and a drive mechanism through which a crankshaft drives the valve actuation mechanism. The drive mechanism is disposed generally above a cylinder block and a cylinder head assembly. At least one guide member is arranged to guide the wire harness and/or the fluid conduit across the engine. The guide member traverses above the drive mechanism.

Abstract: An idle speed control for an engine includes an improved construction. An air induction system for the engine has a plurality of main air intake passages. Each one of the intake passages has its own throttle valve therein. An idle air manifold is disposed for supplying air charges to combustion chambers of the engine through delivery conduits. Amounts of air charges flowing therethrough is controlled by a feedback control system. The sum of cross-sectional areas of the delivery conduits is greater than a cross-sectional area of an inlet portion of the idle air manifold. The respective delivery conduits have restrictions upstream of junctions to the air intake passages.

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 includes a cowling substantially enclosing a four-cycle engine therein. The engine has an air induction device for introducing air to a combustion chamber, and an exhaust system for communicating exhaust products away from the combustion chamber. A pair of camshafts actuate intake and exhaust valves. A variable valve timing (VVT) mechanism is arranged at an upper end of at least one of the camshafts to set the camshaft to an angular position between advanced and delayed angular positions. The cowling includes an air intake, and an engine cover is positioned between the engine and the air intake. The engine cover covers the top and sides of the VVT mechanism so as to protect the VVT mechanism from contact with water that may enter the cowling through the air intake.

Abstract: An engine of an outboard motor includes a fuel injection system. In a preferred mode, the fuel injection system comprises a high pressure fuel system and a vapor separator assembly. The high pressure fuel system includes a fuel injector that is removably attached to the engine. The vapor separator assembly includes a vapor separator and is also removably attached to the engine. The high pressure fuel system and said vapor separator assembly are connected by a quick connector. Preferably, one end of the quick connector is formed from an outlet end of a fuel filter.

Abstract: An induction system for a watercraft is configured to guide air into an engine disposed within the watercraft for combustion therein. The induction system includes an inlet assembly. The inlet assembly includes various constructions for enhancing water preclusive effects.

Abstract: A jet propelled watercraft having an improved extension assembly for dampening pulsations from the impeller of the jet propulsion unit and also an improved exhaust system having a separate idle discharge for permitting lower idle speeds without restriction of the idle exhaust gas flow.

Abstract: A mounting arrangement for a fuel injector comprises a cylinder head, a mounting bore formed in the cylinder head, a seat surface formed within the mounting bore, a fuel injector positioned within the mounting bore and comprising a seating surface, at least one sealing ring disposed about a portion of the fuel injector and positioned between the seating surface and the seat surface. The ring comprises a thermal insulator material and a resin material. The ring also comprises a deformable eyelet that expands radially inward in response to compressive axial forces. The resin material thermally activates at a temperature within the operating temperature range of the engine.

Abstract: An engine has a valve drive arrangement that uses dead space within an outboard motor cowling. The engine has a first set of cylinders and a second set of cylinders. The first set of cylinders is offset from the second set of cylinders such that one is arranged closer to a first end of the engine that the other. The higher set of cylinders includes a set of cam shafts that are coupled at the end closer to the first end of the engine while the lower set of cylinders includes a set of cam shafts that are coupled at the end farther from the first end of the engine. A drive arrangement connects the two sets of cam shafts to the crankshaft.

Abstract: An outboard motor has an exhaust pipe assembly extending through a driveshaft housing. The exhaust pipe is separated into an upstream exhaust pipe and a downstream exhaust pipe which are formed separately from each other. The upstream exhaust pipe depends into the driveshaft housing and has a lower end connected to a pipe support member. An upper end of the downstream exhaust pipe connects to the pipe support member in a manner to communicate with the upstream exhaust pipe. The downstream pipe depends through an opening in a bottom wall of the driveshaft housing, and a mount at the lower end of the pipe is connected to the driveshaft housing in order to secure the pipe in place. The upper end of the downstream exhaust pipe is fit into the pipe support member without the use of fasteners. In this configuration, the downstream exhaust pipe can be removed independently of the upstream exhaust pipe, and can be drawn downwardly through the opening during removal.

Abstract: An internal combustion engine includes at least one combustion chamber formed by at least a first member and a second member that moves relative to the first member. The second member is coupled to an output shaft such that movement of the second member causes the output shaft to rotate. A fuel injection system includes a fuel injector that supplies fuel to the combustion chamber and a fuel pump that supplies fuel to the fuel injector. The fuel injector includes an actuator to regulate an amount of fuel injected by the fuel injector. A main switch has an on position and an off position. A fuel control system includes a controller, which is operatively connected to the actuator, and a sensor, which is arranged to detect rotation of the output shaft. The sensor is adapted to produce a signal that is indicative of rotation of the output shaft and is operatively connected to the controller.

Abstract: The present invention provides an improved oil injection lubrication system for two-cycle engines. The system includes a variable output oil pump, the output of which can be varied in relation to the throttle level. The system also includes a solenoid valve unit containing a plurality of solenoid valves that regulate the flow of oil from the oil pump to each cylinder. The electronic control unit sends control signals to the solenoid valve unit to regulate the flow of oil based upon factors relating to the operation of the engine in accordance with a control scheme. The factors may include those that apply to all of the engine's cylinders (i.e., do not vary between the cylinders), such as intake air temperature, atmospheric pressure, battery voltage, engine break-in period, and load frequency among others.

Abstract: An outboard motor contains a four-cycle engine. The engine includes a lubricant supply system that recirculates lubricant through the engine to lubricate the moving components of the internal combustion engine. The lubricant supply system includes a lubricant cooler. The lubricant cooler is selectively bypassed by lubricant and/or coolant to maintain the proper operating temperature range for the lubricant, depending upon the lubricant temperature and/or the coolant temperature.

Abstract: A marine drive includes a drive shaft having an upper portion, a lower portion, and at least one waist portion between the upper and lower portions. The upper portion is adapted to be coupled to an engine crankshaft and the lower portion is adapted to be supported by bearings and drives a propulsion device through a transmission. The waist portion has a diameter of generally lesser size than the diameters of the upper and lower portions. The waist portion is tapered so that the diameter of the waist portion at its upper end is greater than the diameter of the waist portion at its lower end. The tapered geometry of the waist portion helps distribute impact forces that may occur when the propulsion device is suddenly locked in position when the engine is still running. As a result, failure and damage to the drive shaft waist portion is reduced.

Abstract: A fuel supply for an internal combustion engine includes an improved construction for inhibiting vapor from appearing in the fuel supplied to the engine's combustion chamber(s). A fuel injector, as one of fuel supply devices, is provided for supplying fuel to the combustion chamber of the engine. There are a first and second fuel reservoirs. The first fuel reservoir stores fuel and delivers it to the second fuel reservoir through a first fuel supply conduit, while the second fuel reservoir temporarily store the fuel and delivers it to the fuel injector through a second fuel supply conduit. The excess fuel is returned to the second fuel reservoir from the fuel injector through a fuel return conduit. The fuel supply includes a fuel cooling device for cooling the fuel passing through at least one of the conduits. The construction of the fuel supply and the fuel cooling device permits them to be located with the tight confines between the engine and a protective enclosure (e.g.

Abstract: An outboard motor cooling system includes an improved construction to enhancing cooling of the lubrication system, and more particularly, an oil pan of the lubrication system. The oil pan depends from an engine of the outboard motor and into a driveshaft housing. A periphery coolant jacket is provided around the oil pan. A water pool is defined between the oil pan and the driveshaft housing. An exhaust manifold passes through in a hollow of the oil pan and a water curtain is defined between the hollow wall and the exhaust manifold. An upstanding water passage is also disposed through the oil pan. At least one of an upper and lower transverse water jacket extends transversely above or below the oil pan. No drain water from the engine flows through these jackets or passages. The oil pan therefore is sufficiently cooled. In addition, the upper transverse water jacket increases protection of engine components from heat deterioration.

Abstract: An engine idle control system includes an improved construction for changing an aimed idle engine speed, which is preset by the manufacturer therein, in response to various needs of a user. The engine has a main passage having a throttle valve therein and a bypass passage arranged to bypass the throttle valve. The bypass passage supplies an idle air charge to a combustion chamber of the engine when the throttle valve is generally closed and has an adjusting valve therein for adjusting the idle air charge. A control device controls the adjusting valve to reduce a difference between an actual idle speed sensed by an engine speed sensor and an aimed idle speed preset in the control device. The control device includes means for changing the aimed idle speed.

Abstract: An outboard motor includes a power head, driveshaft housing and lower unit, and employs a cooling system to cool the driveshaft housing. Portions of the driveshaft housing experience substantial heat transfer from the exhaust gases that pass through the driveshaft housing. The driveshaft housing cooling system cools the heated portions of the driveshaft housing. The cooling system includes delivery pipes adapted to deliver water to the outer surface of each side of the driveshaft housing. The water is distributed to the housing outer surface in a manner to establish a substantially even flow across the surface so that heat is dissipated from the housing in order to prevent the housing from reaching very high temperatures.