One embodiment of the invention relates to an internal combustion engine including an engine block having a first cylinder and a second cylinder, a crankshaft configured to rotate about a crankshaft axis, a flywheel coupled to the crankshaft, a throttle body, an air filter assembly, a first electric fan coupled to a first duct, and a second electric fan coupled to a second duct. The first duct is configured to direct cooling air directly over the first cylinder. The second duct is configured to direct cooling air directly over the second cylinder. The first cylinder is at least partially within the first duct. The second cylinder is at least partially within the second duct.

A motorcycle intake air guide for feeding an intake air volumetric flow to a motorcycle internal combustion engine includes an unfiltered-air channel, a filtered-air channel, and an air filter therebetween. An intake air guide valve provided in the unfiltered-air channel is configured to change a cross-section of the unfiltered-air channel cross-section. The unfiltered-air channel has a double-flow design at least in sections with a first unfiltered-air partial channel and a second unfiltered-air partial channel which are merged downstream of a steering head of a frame of the motorcycle in a collection region of the unfiltered-air channel. The intake air guide valve is arranged in the collection region, downstream of the first and second unfiltered-air partial channels.

A vehicle has a frame, wheels, left and right seats each having a seat base, an internal combustion engine disposed rearward of the seat bases, an air induction system fluidly connected to the engine, at least one side body panel and an access panel. The air induction system has an air inlet, an air filter, and a throttle body. The at least one side body panel is connected to a side of the frame and defines an aperture. The access panel is movable between a first position and a second position. In the first position, the access panel is connected to the at least one side body panel and covers the aperture. In the second position, the access panel exposes the aperture. The air filter is accessible through the aperture when the access panel is in the second position. A method for removing an air filter is also disclosed.

A throttle device, comprising: a throttle valve (13) disposed in a plurality of intake passages (12) of a throttle body (11); a throttle shaft (14) supporting the throttle valve (13); a motor (15) for driving the throttle valve (13) to open and close through the throttle shaft (14); a rotation transmission mechanism (20) interposed between the motor (15) and the throttle shaft (14); and a position sensor to detect a displacement in the rotation transmission mechanism (20). The rotation transmission mechanism (20) includes a pinion (21) driven by the motor (15) and a control gear (23) interlocked with the pinion (21) and integrally connected to the throttle shaft (14). The position sensor (30) to detect an angular displacement of the control gear (23) and the rotation transmission mechanism (20) are disposed between the plurality of intake passages 12.

A utility vehicle includes a plurality of ground-engaging members, a frame supported by the ground-engaging members, and a plurality of body panels supported by the frame. The utility vehicle also includes a radiator supported on a rear portion of the frame. Additionally, the utility vehicle includes an air intake assembly partially supported by an upper portion of the frame.

An air intake system includes an air cleaner for housing an air filter element therein above an off road vehicle engine, and a surge tank, which buffers the filtered air, at a location beside the engine. A descending tube from the air cleaner connects into a top cover of the surge tank, and an outlet tube of the air intake system extends horizontally from the top cover of the surge tank for connection into the throttle of the engine. A vapor recovery pipe connect the crankcase of the engine, lower than the outlet tube, back up to the air cleaner upstream of the filter element. The surge tank includes a tank bottom casing removably connected to a tank upper cover, with the descending tube and the outlet tube connecting into the tank upper cover.

The presently disclosed subject matter is generally directed to a system and method of protecting vehicle engines by preventing water from entering the belt drive and/or air intake of the vehicle motor. The disclosed system includes a housing and one or more snorkels that extend in an upward direction from the housing. Each snorkel includes a water sensor that detects the level of water outside of the vehicle. When water reaches the snorkel maximum depth and triggers the sensor, valve within the housing closes to divert water away from the motor. Once the vehicle is back on dry land, the user can reset the valve to the open position.

A utility vehicle includes a plurality of ground-engaging members, a frame supported by the ground-engaging members, and a plurality of body panels supported by the frame. The utility vehicle also includes a radiator supported on a rear portion of the frame. Additionally, the utility vehicle includes an air intake assembly partially supported by an upper portion of the frame.

An air intake system for a vehicle has a conduit having an internal wall forming an air passage. A deflector is disposed within the air passage. A restricting structure is disposed within the air passage between the deflector and a conduit outlet. The restricting structure defines at least in part an opening substantially laterally aligned with the deflector. The restricting structure has a lateral wall disposed downstream of the deflector and extending within the air passage. The lateral wall has a front surface generally facing a conduit inlet, and a plurality of surface-increasing features provided on the front surface. Each of the surface-increasing features has a length of at least 1 mm measured from the front surface in a direction normal thereto. An air intake system having a collector connected to the deflector and positioned to collect at least some moisture from air flowing past the deflector is also described.

An air intake structure for introducing an intake air into an engine includes: a first air intake passage fluidly connected with an air outlet; a second air intake passage branched off from the first air intake passage and having a passage length greater than that of the first air intake passage; and an open-close valve provided in the first air intake passage. The second air intake passage has a portion thereof bent to allow the flow of intake air in one direction reverse to that of the air flowing a different portion thereof. The first air intake passage, the second air intake passage and the open-close valve are provided within an air cleaner.