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 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: 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: 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: 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: 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: 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 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.

Abstract: An engine includes an air induction system, a fuel supply system, a lubrication system and a ventilation system. The fuel supply system has a fuel reservoir in which a space for fuel vapors is defined. The lubrication system lubricates a component of the engine with lubricant. The ventilation system couples a crankcase of the engine with the air induction system so as to deliver oil vapors in the crankcase to the air induction system. A fuel vapor passage is arranged to couple the space of the fuel reservoir with the ventilation system.

Abstract: An outboard motor includes an improved arrangement for an exhaust system, in association with a lubricant tank and a cooling system, for a four-cycle internal combustion engine that powers the outboard motor. The cooling system discharges coolant independent of an exhaust pipe and an expansion chamber of the exhaust system so as to inhibit an influx of coolant into the engine should the engine become temporarily disabled. In addition, the cooling system provides a pool or bath of coolant between the exhaust pipe and the lubricant tank to inhibit excessive heating of these components during normal and abnormal running conditions (i.e., if the engine becomes disabled).

Abstract: A personal watercraft features a four-cycle engine. The four-cycle engine has an intake valve and an exhaust valve. The intake valve and the exhaust valve are controlled through a use of a cam drive arrangement. The cam drive arrangement is contained within a protective housing. A number of waterjackets are provided to the housing to control the temperature within the housing. In addition, the watercraft features a protective housing in which a starter motor is mounted to the cylinder block. The housing features two members that can be mounted to the cylinder block together while one member can be removed for access to the starter motor.

Abstract: An outboard motor features a compact throttle control and transmission shifting control on a handle connected to a tiller. An interlock is designed to limit the maximum engine speed at which the engine can be operated when in the transmission is in neutral and to lock the transmission in neutral or out of neutral when the engine is operated at a speed greater than a second speed that is less than the maximum speed.

Abstract: A lubrication system for an outboard motor engine includes a pump housing includes an inlet port through which lubricant enters the pump housing and an outlet port through which the lubricant is discharged from the pump housing. Both the crankshaft and the driveshaft extend through an opening defined at the pump housing and are couple with each other within the pump housing. A first seal member is disposed around the crankshaft for sealing a first location between an outer surface of the crankshaft and a first inner surface of the pump housing that defines at least a portion of the opening. A second seal member is disposed around the driveshaft for sealing a second location between an outer surface of the driveshaft and a second inner surface of the pump housing that also defines at least a portion of the opening.

Abstract: A tilt stop mechanism for an outboard drive assembly includes an improved construction that is easy to handle and can be provided in a relatively narrow space of a support assembly. The support bracket includes a pair of transversely spaced portions. At least a portion of the outboard drive assembly is interposed between the spaced portions. A tilt pin couples the drive assembly to the support bracket for pivotal movement about a tilt axis extending generally horizontally. A tilt stop member is coupled to the drive assembly for pivotal movement about a pivot axis extending generally horizontally. The tilt stop member has at least one stopper portion extending between the drive assembly and the support bracket when the drive assembly is in a tilted-down position. The support bracket has at least one recess. The stopper portion engages with the recess by the pivotal movement of the tilt stop member when the outboard drive is in a tilted-up position.

Abstract: An arrangement of components for an engine includes an improved construction. An exhaust system of the engine has an exhaust manifold extending along an cylinder body. At least a part of an air induction system of the engine exists to overlap with the exhaust manifold in a view along an extending axis of the exhaust manifold. A cooling system having at least two coolant passages is further provided. A coolant flow control mechanism is arranged to prevent only the coolant within one of the passages from flowing therethrough when temperature of the coolant is lower than a predetermined temperature.

Abstract: An outboard motor comprising a water propulsion device and a cowling housing an internal combustion engine is disclosed. The engine has a body defining at least one combustion chamber and an output shaft arranged to drive the water propulsion device. The cowling has a front end and a rear end. The motor includes a handle which generally encircles at least a portion of the cowling, the handle having at least one gripping portion at the front or rear end of the cowling.

Abstract: An outboard motor includes a cowling covering an internal combustion engine having a plurality of horizontally arranged cylinders. A high pressure fuel pump drive unit is arranged so as to be offset from the axes of the cylinders, at an upper end of the engine. The electrical system is provided on a first side of the engine body and a fuel system is provided on the opposite side of the engine body. Arranged as such, the components of the engine form a compact unit thus reducing the overall size of the cowling. Additionally, fuel lines and electrical conduits which connect the various components of the respective fuel and electrical systems are separated from each other.

Abstract: A jet propelled watercraft having an improved extension assembly for dampening pulsations from the impeller of the jet propulsion unit and also for mounting the jet propulsion unit. The structure simplifies the overall assembly and permits individual tuning with conventional units.

Abstract: The present vehicle data system collects, encodes, transmits, decodes, and displays engine and vehicle operation information. In one mode, an engine control unit of an outboard boat motor receives a plurality of engine and vehicle operation parameters from a plurality of sensors. The engine control unit encodes the plurality of parameters in a single signal and transmits the encoded signal to a display unit over a signal line. The display unit decodes the encoded signal to extract the plurality of parameters and displays the extracted parameters to the vehicle operator.