An air intake structure of a saddle riding vehicle is disposed in the saddle riding vehicle in which a frame including a left and right pair of main frames and an air box are disposed, an intake passage is disposed between the main frames and an outer periphery of the head tube, and the intake passage includes: a front side intake duct that extends forward; and a rear side intake duct that couples the air box to the head tube. In the air intake structure of the saddle riding vehicle, the rear side intake duct is a separate body from the air box, the air box has a front surface on which an opening inserted through the rear side intake duct is provided, and the rear side intake duct is coupled to an intake passage from an inside of the air box through the opening.

An engine cover covers an engine; and an intake pipe through which the air is introduced into the engine. An intake silencer is provided adjacent to the intake pipe and suppresses air pressure fluctuations of air in the intake pipe to reduce intake sound. A portion of the intake silencer is covered with the engine cover, and a remaining portion is exposed with respect to the engine cover. An advantage is that secondary noise generated by the intake silencer and a temperature increase of air suctioned into the engine are simultaneously suppressed.

A vehicle includes an engine, an engine cover, and a cross component. The engine cover has a through-hole through which the cross component passes. The cross component is a flexible hose or a flexible pipe in which a body part extending in a cross direction is integrated with a diameter enlarged part having a diameter larger than the body part. The outer peripheral part of the diameter enlarged part makes close contact with the inner peripheral surface of the through-hole of the engine cover.

Systems and methods are provided for an air filter device. In one example, the air filter device includes a housing enclosing a filter element positioned in a filter enclosure, the filter element including an outlet in fluidic communication with a downstream intake line and an inlet conduit extending through the housing and delivering air to the filter enclosure, and the inlet conduit including a wall dividing the filter enclosure from the inlet conduit. The air filter device further includes a cover sealingly attached to the wall and a peripheral lip of the housing.

An intake plenum is for a marine engine, the marine engine having first and second throttle devices for controlling flow of intake air to the marine engine. The intake plenum has an airbox providing an expansion volume, first and second inlets that convey the intake air in parallel to the expansion volume, first and second outlets that convey the intake air in parallel from the expansion volume to the first and second throttle devices, and first and second Helmholtz-style attenuator devices located at the first and second outlets, respectively. Together the first and second inlets, expansion volume, and first and second Helmholtz-style attenuator devices are configured to attenuate different frequencies of sound emanating from the marine engine via the first and second outlets.

An engine includes an intake manifold and an air-induction system configured to deliver air to the intake manifold. The air-induction system includes a throttle attached to the intake manifold, an air cleaner, conduit connecting between the air cleaner and the throttle to create a flow path therebetween, and a valve disposed in the flow path to be upstream of the throttle and downstream the air cleaner. The valve has a closed position in which the flow path is blocked to hold hydrocarbons within the intake manifold and inhibit emission therefrom and has an open position in which the flow path is unimpeded.

An apparatus and a method are provided for an aircharger air intake system for filtering and conducting an airstream to an air intake of an engine. The aircharger air intake system includes an air filter comprising a filter medium configured to entrap particulates flowing within the airstream. An air box comprising one or more sidewalls and a mount wall is configured to support the air filter within an engine bay. The air box is configured to be mounted, or fastened, onto the engine. An intake tube is coupled with the air filter and configured to conduct the airstream to the air intake of the engine. The intake tube is configured to be coupled with an air temperature sensor or a mass air sensor of the engine. An adapter is configured to couple the intake tube with the air intake.

A particle separator assembly includes an airbox providing an outer tapered portion tapering from a first section having a first cross sectional area to a first opening having a second cross sectional area less than the first cross sectional area. The example assembly includes a flow diverter providing an inner tapered portion that tapers to a second opening. The example assembly includes an air filter housed by the airbox, the air filter is spaced from the second opening in a first direction, and the first opening is spaced from the second opening in a second direction opposite the first direction.

A variable intake system for a vehicle is provided and includes an air cleaner that filters air via a filter and supplies the air to an engine. A main duct is connected to the air cleaner to supply the air, and a variable valve has a housing that is coupled and mounted to a mounting aperture of a mounting part disposed on a front end of the filter of the air cleaner. An internal passage of the housing is opened by suction pressure of the engine in the mounting part to suction external air. A projection formed on the housing of the variable valve is inserted into a projection seat formed in the mounting part, so that the variable valve is secured to the mounting part.

A pulse ring assembly for air cleaner systems that is adapted to produce a pulse ring of gas to clean a filter element. The air cleaner system may include an outer tube and an inner tube configured to receive the inner tube such that at least a portion of an interior surface of the outer tube faces at least a portion of an exterior surface of the inner tube. The outer tube may include a pulse port extending between the interior and exterior surfaces of the outer tube into an outer tube passageway. Filtered air may be configured to flow from a first filter cartridge, through the outer and inner tubes, and to an engine intake. The system may also include a pulse jet apparatus in fluid communication with the pulse port of the outer tube and configured to direct gas through the pulse port towards the first filter cartridge.