Abstract: The present invention provides a system and method of adaptively setting the idle speed of an internal combustion engine based on instantaneous power requirements of the engine. By adaptively setting engine idle speed based on instantaneous power requirements of the engine as well as the power requirements of any auxiliary devices, the noise and exhaust emissions of the engine may be reduced as well as improving fuel consumption efficiency. The engine's electronic control unit (ECU) is designed to regulate an idle speed controller based on current feedback received from sensors operationally connected to the engine as well as the various auxiliary devices. The ECU regulates the idle speed control such that the engine electronics are sufficiently energized to run the engine, but the engine idle speed is also set to a level that takes into account the instantaneous power requirements of the various system components and/or devices.

Abstract: A detachable passenger seat is selectively mountable onto a base frame of a snowmobile having a straddle-type rider seat. The passenger seat includes a cushioned seat portion supported by a seat frame. A forward portion of the passenger seat includes a bottom surface contoured to fit over and be supported by at least a portion of a rearward end of the rider seat when the passenger seat is attached to the snowmobile. Upwardly extending flexible grab handles are mounted to the lateral sides of the seat frame. Upper portions of the flexible grab handles extend higher than at least a portion of an upper surface of a cushioned seat portion of the passenger seat. The flexible grab handles are designed to be rigid enough to provide support to a passenger and flexible enough to allow a passenger to easily dismount the snowmobile.

Abstract: A system and method for operating a combustion engine including a combustion chamber operable in at least a first operating mode and second operating mode. An engine control unit (ECU) performs conductivity sensing within the combustion chamber and interprets the results. Specifically, the ECU determines the current between a pair of spark plug electrodes placed within a combustion chamber of a combustion engine prior to, or after, combustion. The ECU determines whether the current between the pair of electrodes is indicative of spark plug fouling. If spark plug fouling is determined, the ECU can modify the mode of operation to correct the spark plug fouling and clean the deposits on the spark plug while the engine is in operation and without operation intervention.

Abstract: A system and method for constructing a reverse gate for a watercraft is disclosed. The reverse gate is independently rotatable relative to a watercraft and a steering nozzle and includes at least two curved surfaces. The curved surfaces are attached to one another to form an apex that is offset from a midpoint of the reverse gate and the reverse gate is attached to the watercraft so that the apex is also offset from a center axis of a steering nozzle oriented relative thereto. Water discharged from the steering nozzle can be diverged at the apex of the reverse gate to provide lateral and reverse thrust to the watercraft. The reverse gate includes an additional curved section contained within one of the at least two curved sections to provide improved lateral thrust to the watercraft.

Abstract: An all terrain vehicle (ATV) includes a plurality of wheels and a fender structure positioned over the wheels having a support portion designed as and defining a load-bearing surface. The fender structure may include a plurality of raised support portions that increase rigidity and load capacity. Additionally, it is not necessary to support either the fender structure or the support portion using the bumper of the ATV. The fender structure may be formed with plastic material, such as polyethylene, polypropylene or fiberglass-charged polyethylene, and may be manufactured using a blow-molding technique or an injection molding technique. The ATV may also include mud guards and a floor board that extends between the mud guards. The mud guards and the floor board may be formed as an integral or one piece unit with the fender structure. The mud guards can be injection molded or blow-molded while the fender structure can be blow-molded.

Abstract: A watercraft, equipped with a jet propulsion system with improved efficiency of operation is disclosed. Structures are disposed within a water passage of the jet propulsion system at a position upstream of the jet propulsion unit that modulate the amount of water that is allowed to pass through the water passage. The structures can be a flexible fluid filled bag, an adjustable ride plate, and an additional water passage. Each of the structures allow a greater amount of water into the water passage during acceleration than during constant speed travel of the watercraft.

Abstract: A noise-reducing engine enclosure for an engine includes first and second members removably mounted to one another in cooperating relation to define an engine receiving space therebetween. The first and second members each include a noise-reducing layer of material to reduce noise transmission to the atmosphere outside of the engine enclosure during operation. The first and second members are movable between (1) an engine accessing position, wherein the first and second members are positioned to allow access to the engine during operation and (2) an engine enclosing position, wherein the first and second members cooperate to define the engine receiving space to receive and enclose the engine therein such that noise transmission to the atmosphere during operation is reduced.

Abstract: A suspension for a vehicle includes an upper A-arm and a lower A-arm. A leg with an axis is rotatably connected to both the upper A-arm and the lower A-arm. A mechanical link is rotatably connected to the leg so that movement of the mechanical link applies rotational force to the leg to cause the leg to rotate about the axis.

Abstract: A light weight piston for an internal combustion engine is disclosed that minimizes the stresses found in a transition area between the piston head and the associated piston pin bosses while maintaining a flexible soft connection between the piston skirts and the piston head. The piston includes a pair of piston skirts having tapered edges. Flared connecting walls are provided such that the distance between the connecting walls is minimized adjacent a pair of piston pin bosses and the distance between the connecting walls is maximized adjacent a portion of the tapered edges. The connecting wall flares in a generally outward direction such that at least a portion of the inner surfaces of the connecting wall has a generally convex curvature.

Abstract: A snowmobile is described having a frame with left and right sides with left and right suspension assembly disposed thereon. Left and right spindles are connected to the left and right suspension assemblies. A left ski is pivotally attached to the left spindle and a right ski is attached to the right spindle. Rotation of the left and right spindles alters the ski stance of the snowmobile. The stance may also be altered in other ways, which are also disclosed.

Abstract: A helmet is particularly well suited for cold-weather use. The helmet includes a jaw shield that is detachable from a head portion. A breathing mask connects to the jaw shield via a mask adjustment mechanism that selectively axially moves the breathing mask toward and away from an inner surface of the jaw shield to precisely and accurately position the breathing mask against the nose and mouth of the helmet's wearer. A spring-loaded quick-release tinted shield is controlled by a lever that selectively raises and lowers the tinted shield. An eye shield pivotally connects to the helmet and is disposed in front of the tinted shield. An eye shield heating system on the eye shield electrically connects to the head portion of the helmet to provide electric power to the heating system.

Abstract: A hybrid fuel/electric powered watercraft includes an electronic turning machine (ETM), and internal combustion engine, and a propulsion system, which are operatively connected to each other, preferably via one or more clutches. An electronic control unit (ECU) controls the ETM, clutch(es), and engine. At low speeds, the ECU disengages at least one clutch and solely uses the ETM to power the propulsion unit and propel the watercraft. At high speeds, the ECU engages the clutch and uses both the engine and the ETM or just the engine to power the propulsion system. When the watercraft's battery discharges, the ECU operates the ETM in a generator mode and runs the engine to charge the battery. The watercraft can also include a shore button feature that selectively limits/governs the speed of the watercraft. A clutch may be used to avoid driving the propulsion system when the engine is idling or being started.

Abstract: Variable venturi for use in jet propulsion systems of watercraft include discharge openings with selectively variable discharge areas that enable a venturi controller to selectively maximize top speed, acceleration, and/or fuel efficiency. The variable venturi may include a plurality of circumferentially-spaced, squeezable, flexible sections that selectively move radially inwardly to alter the discharge area. Alternatively, the variable venturi may include a flexible venturi with a variably-shaped flexible discharge opening. Alternatively, the variable venturi may include a main rear discharge opening and a plurality of additional discharge openings with selectively openable valves, whereby selective opening of the valves effectively increases the discharge area. Alternatively, the variable venturi may have a movable end flap that selectively varies the discharge area.

Abstract: A suspension system for an ATV is provided that includes a torsion control mechanism having a left connecting structure and a right connecting structure. The torsion control mechanism defines an axis of rotation passing through the left and right connecting structures. A left swing arm is fixedly connected to the left connecting structure and a right swing arm is fixedly connected to the right connecting structure, such that the right and left swing arms are pivotable about the rotation axis defined by the torsion control mechanism.

Abstract: A shock absorber includes a shock rod and piston which are disposed within a fluid chamber within a shock body. The piston separates the shock body fluid chamber into a compression fluid chamber and a rebound fluid chamber. A reservoir fluid chamber accommodates the entry of the shock rod into the fluid chamber as the shock absorber compresses under shock forces. The compression fluid chamber is in fluid communication with the reservoir fluid chamber through a third chamber or passage. A first valve may control passage of fluid from the compression fluid chamber into the passage. Second and third valves may be disposed within the passage in parallel with each other and in series with the first valve. The third valve may include an easily accessible knob disposed outside the shock body.

Abstract: A dry sump lubrication system for a four cycle engine is disclosed. The dry sump lubrication system has at least two lubricant storage chambers. A first lubricant storage chamber stores a first volume of lubricant. The first lubricant storage chamber may be located in a lower part of the crankcase. A second lubricant storage chamber is an oil tank and stores a second volume of lubricant. The oil tank may be secured to the output end of the crankcase. The first lubricant storage chamber is capable of storing at least 30% of a total volume of lubricant within the dry sump lubrication system.

Abstract: In a snowmobile or other vehicle, ventilation of ambient air to the engine compartment is necessary. However, from time to time when encountering deep snow or extremely cold temperatures, it may be necessary to restrict the inflow of ambient air into the engine compartment. An adjustable air vent having a sliding ventilation grill adjusts the air flow. The air vent has actuators for adjusting the air flow that are simple and easily manually operable by an operator even when wearing gloves or mittens without the need of any tools.

Abstract: The present invention is directed to a lubrication system for a multi-cylinder internal combustion engine. An inter-cylinder lubricant communications system is provided to circulate lubricant from an upper-most cylinder to each successive cylinder downstream. This system includes an inlet that extends through an opening in the wall of a downstream cylinder. An outlet situated upstream relative to the inlet is also provided and includes an accumulation region to collect lubricant as it flows with the charging air from the crankcase chamber to the combustion chamber of an engine cylinder. A fluid passage is configured to fluidly interconnect the inlet to the outlet to pass lubricant from the upstream cylinder to the downstream cylinder. A passage is provided from the most downstream cylinder to the most upstream cylinder thereby allowing for re-circulation of the lubricant.