Abstract: A steering assist system for a watercraft including a force detection assembly adapted to detect a force further applied to an operator steering control of the watercraft after the steering control is turned to a maximum turning position. The steering assist system also includes a controller configured to increase a steering force produced by the watercraft in response to an output of the force detection assembly. In one arrangement, the steering assist system increases an output of a propulsion system of the watercraft in proportion to an output of the force detection assembly. In another arrangement, the steering assist system moves a steering force producing member, such as a deflector or rudder, for example, in response to an output of the force detection assembly in addition to, or alternative to, increasing an output of the propulsion system.

Abstract: A steering assist system for a watercraft including a force detection assembly adapted to detect a force further applied to an operator steering control of the watercraft after the steering control is turned to a maximum turning position. The steering assist system also includes a controller configured to increase a steering force produced by the watercraft in response to an output of the force detection assembly. In one arrangement, the steering assist system increases an output of a propulsion system of the watercraft in proportion to an output of the force detection assembly. In another arrangement, the steering assist system moves a steering force producing member, such as a deflector or rudder, for example, in response to an output of the force detection assembly in addition to, or alternative to, increasing an output of the propulsion system.

Abstract: A steering assist system for a watercraft including a force detection assembly adapted to detect a force further applied to an operator steering control of the watercraft after the steering control is turned to a maximum turning position. The steering assist system also includes a controller configured to increase a steering force produced by the watercraft in response to an output of the force detection assembly. In one arrangement, the steering assist system increases an output of a propulsion system of the watercraft in proportion to an output of the force detection assembly. In another arrangement, the steering assist system moves a steering force producing member, such as a deflector or rudder, for example, in response to an output of the force detection assembly in addition to, or alternative to, increasing an output of the propulsion system.

Abstract: A steering assist system for a watercraft including a force detection assembly adapted to detect a force further applied to an operator steering control of the watercraft after the steering control is turned to a maximum turning position. The steering assist system also includes a controller configured to increase a steering force produced by the watercraft in response to an output of the force detection assembly. In one arrangement, the steering assist system increases an output of a propulsion system of the watercraft in proportion to an output of the force detection assembly. In another arrangement, the steering assist system moves a steering force producing member, such as a deflector or rudder, for example, in response to an output of the force detection assembly in addition to, or alternative to, increasing an output of the propulsion system.

Abstract: A number of embodiments of personal watercraft having catalytic exhaust systems for treating and purifying the exhaust gases. In all of the embodiments, the catalyst is positioned and disposed so as to be protected from water. In addition, arrangements are provided for cooling the catalyst, for circulating ventilating air across it, for isolating it from other components such as the fuel tank, and for permitting its flushing with fresh water after operating in a salt water environment.

Abstract: An exhaust pipe cooling system regulates the temperature of a exhaust system catalyzer on a small watercraft to ensure proper functioning and to inhibit overheating of the catalyzer. The cooling system supplies fresh water to a water jacket which surrounds the catalyzer in a manner independent of an engine cooling system. The cooling system also supplies fresh water to an upwardly oriented discharge nozzle. The upward water jet from the nozzle spays well above the surface of the body of water in which the watercraft is operated to provide a visible indicator of location of the small watercraft. A control valve regulate the flow rate of water through the cooling system to adjust the temperature of the catalyzer to fall within a desired range of operating temperatures.

Abstract: A number of embodiments of personal watercraft having catalytic exhaust systems for treating and purifying the exhaust gases. In all of the embodiments, the catalyst is positioned and disposed so as to be protected from water. In addition, arrangements are provided for cooling the catalyst, for circulating ventilating air across it, for isolating it from other components such as the fuel tank, and for permitting its flushing with fresh water after operating in a salt water environment.

Abstract: An improved fuel delivery and injection system for a small watercraft engine reduces the heat effects within an enclosed engine compartment upon various components of the engine and upon the fuel within the fuel system. The fuel system integrates a fuel pump within a fuel tank at a location which minimizes the effects of watercraft leaning. The inlet of the fuel pump desirably corresponds, in the lateral direction, with a position of an inlet to the jet pump unit. In this position, the pump is less likely to draw air as the watercraft maneuvers. The fuel lines also are arranged within the engine to minimize the effect of engine heat produced by the exhaust system on the fuel delivery lines. The arrangement of the fuel pump and fuel delivery lines consequently improves the consistency of the fuel/air ratio within the fuel charge produced by the engine as less air and vapor delivered to the fuel injectors.

Abstract: A mounting arrangement for a throttle position sensor associated with a throttle valve is disclosed. The throttle valve is positioned within an intake pipe of an intake system of an engine which is positioned in an engine compartment defined by a hull of a watercraft. An output shaft of the engine is arranged to drive a water propulsion device of the watercraft. The intake pipe extends from the engine and is arranged to route air to a combustion chamber of the engine. The throttle position sensor is mounted so as to be shielded by the intake pipe from a source of water within the engine compartment, such as an outlet of an intake duct leading through the hull of the watercraft.

Abstract: An improved fuel delivery and injection system for a small watercraft engine reduces the heat effects within an enclosed engine compartment upon a fuel pump of and the fuel within a fuel injection system. The fuel delivery system includes a vapor separator and a high-pressure fuel pump. The fuel pump is at least partially located within the vapor separator. The fuel within the vapor separator cools the fuel pump. The vapor separator also is positioned between a pair of air ducts such that an air stream between the ducts cools the fuel within the vapor separator. This arrangement consequently improves the consistency of the air/fuel ratio in the fuel charges delivered to the engine cylinders, provides a compact structure between the fuel pump, and the vapor separator and improves the durability of the fuel pump.

Abstract: An improved fuel delivery and injection system for a small watercraft engine reduces the heat effects within an enclosed engine compartment upon various components of the engine and upon the fuel within the fuel system. The fuel system integrates a fuel pump within a fuel tank at a location which minimizes the effects of watercraft leaning. The inlet of the fuel pump desirably corresponds, in the lateral direction, with a position of an inlet to the jet pump unit. In this position, the pump is less likely to draw air as the watercraft maneuvers. The fuel lines also are arranged within the engine to minimize the effect of engine heat produced by the exhaust system on the fuel delivery lines. The arrangement of the fuel pump and fuel delivery lines consequently improves the consistency of the fuel/air ratio within the fuel charge produced by the engine as less air and vapor delivered to the fuel injectors.

Abstract: An improved fuel delivery and injection system for a small watercraft engine reduces the heat effects within an enclosed engine compartment upon a fuel pump of and the fuel within a fuel injection system. The fuel delivery system includes a vapor separator and a high-pressure fuel pump. The fuel pump is at least partially located within the vapor separator. The fuel within the vapor separator cools the fuel pump. The vapor separator also is positioned between a pair of air ducts such that an air stream between the ducts cools the fuel within the vapor separator. This arrangement consequently improves the consistency of the air/fuel ratio in the fuel charges delivered to the engine cylinders, provides a compact structure between the fuel pump, and the vapor separator and improves the durability of the fuel pump.

Abstract: A marine engine is constructed having an improved component layout so as to reduce the tendency of an engine fuel pump being exposed to water. This advantage is accomplished while shielding the fuel pump from water that may enter through an access opening above the engine. In one form the fuel pump is mounted under an air intake system of the engine. The fuel pump is also desirably arranged to reduce thermal effects on the fuel pump by positioning the fuel pump on an air intake pipe of the engine. In another from, the fuel pump is mounted under and inclined cylinder block and an exhaust system.

Abstract: An improved fuel delivery and injection system for a small watercraft engine reduces the heat effects within an enclosed engine compartment upon various components of the engine and upon the fuel within the fuel system. The fuel system integrates a fuel pump within a fuel tank at a location which minimizes the effects of watercraft leaning. The inlet of the fuel pump desirably corresponds, in the lateral direction, with a position of an inlet to the jet pump unit. In this position, the pump is less likely to draw air as the watercraft maneuvers. The fuel lines also are arranged within the engine to minimize the effect of engine heat produced by the exhaust system on the fuel delivery lines. The arrangement of the fuel pump and fuel delivery lines consequently improves the consistency of the fuel/air ratio within the fuel charge produced by the engine as less air and vapor delivered to the fuel injectors.

Abstract: A lubricant supply system is provided for the induction system of a marine propulsion engine. The lubricant supply system delivers lubricant to the a flow controlling valve in the induction system upon shutting down of the engine and can be operated manually at the discretion of a user. The lubricant serves to reduce the likelihood of post-operation corrosion of the valve, particularly at the sliding support surfaces of the valve and also provides lubricant from startup operation.

Abstract: A personal watercraft includes a catalytic exhaust system in order to reduce discharge of pollutants. The exhaust system includes an exhaust passage and a catalyzer that is located within an expansion chamber of the exhaust passage. A water jacket is provided adjacent the expansion chamber and a portion of water from the water jacket merges with the exhaust pipe at a merge point downstream from the catalyzer. The distance within the exhaust passage between an exhaust port of a combustion chamber and the front of the catalyzer and from the rear of the catalyzer to the coolant-exhaust merge point is such that a pressure wave from the combustion chamber reflects back from downstream of the catalyzer carries an exhaust/water mixture from the merge point upstream across the catalyst, thereby cooling the catalyzer. Also, an insertion port disposed in the exhaust system upstream of the catalyzer injects cooling water into the exhaust system, thus cooling the exhaust gases and the catalyzer.

Abstract: A marine engine is constructed having an improved component layout so as to reduce the size of the engine even when multiple fuel injectors are employed per cylinder. In one mode, this advantage is accomplished while shielding the fuel injectors from water that may enter through an access opening above the engine. The fuel injectors are also desirably arranged to reduce thermal effects on the fuel injectors by remotely positioning the fuel injectors relative to the engine's exhaust system. In one form, the fuel injectors are mounted on a lower surface of an inclined cylinder and the exhaust pipe is connected to an upper surface of the cylinder for these purposes.

Abstract: In accordance with the present invention, there is provided a control for an engine of a watercraft. The watercraft is preferably of the personal variety, and includes a water propulsion device which is driven by an output shaft of the engine. The engine has at least one combustion chamber, an intake system providing air to the combustion chamber, a fuel system providing fuel to the combustion chamber for combustion therein, and an ignition system including at least one ignition element associated with the combustion chamber. The watercraft engine control is of the type which does not include a main switch, but is arranged to turn on electrical systems of the engine when the engine is started and shut them off when the engine is stopped. The control includes a lanyard switch having first and second positions. In a first position the lanyard switch permits power to flow to the ignition element and the electrically-powered engine features, such as a fuel delivery mechanism.

Abstract: An arrangement for at least one fuel injector associated with a fuel injection system of an engine powering a water propulsion device of a watercraft is disclosed. The watercraft has a hull defining an engine compartment and includes a water propulsion device. An internal combustion engine has a cylinder head connected to a top end of a cylinder block and cooperating with the cylinder block to define at least one combustion chamber. The engine is positioned in the engine compartment and has an output shaft arranged to power the water propulsion device. At least one air duct provides air through the hull into the engine compartment, the duct leading from the hull to an outlet in the engine compartment. The engine has an intake system for providing air to the combustion chamber and a fuel system for providing fuel to the combustion chamber, the fuel system including at least one fuel injector extending from the cylinder head positioned above the air duct outlet and shielded by the engine from water.

Abstract: A two-cycle internal combustion engine for a watercraft that includes a cylinder block having a cylinder bore, a piston reciprocating in the cylinder bore and an exhaust port formed in the cylinder block. An exhaust path extends from the cylinder bore for exhausting combustion products from the cylinder bore. An exhaust control valve cooperates with the exhaust port and is movable between at least a first position for advancing the closing of the exhaust port so as to increase the compression ratio in the engine and a second position for delaying the closing of the exhaust port so as to decrease the compression ratio in the engine. Means for controlling the exhaust control valve between the first and second position are provided and are controlled in response to a watercraft condition.