An exhaust manifold comprises a plurality of exhaust intake conduits structured to be fluidly coupled to an engine and receive exhaust gas from a corresponding cylinder of the engine. At least one exhaust intake conduit provides a reduction in an exhaust intake conduit cross-sectional area from an inlet to an outlet. A plurality of bends are each defined by a respective one of the exhaust intake conduit outlets. An exhaust intake manifold is fluidly coupled to the exhaust intake manifold and defines an exhaust intake manifold flow axis. Each of the plurality of bends is shaped so as to define n angle of approach of exhaust gas flowing therethrough. A first angle of approach of the first bend relative to the exhaust intake manifold flow axis is smaller than a second angle of approach of an inner second bend.

An air cleaner of a vehicle for filtering particulate matter from air supplied through an intake includes a case with an outlet. The case surrounds the air cleaner, which further includes two connecting tubes each having a first end disposed through the outlet and a second end located in the case. A funnel is clamped to the second end of each of the connecting tubes. A bracket is attached to each of the funnels for rigidly mounting the funnels inside the case of the air cleaner. The first end of each of the connecting tubes is further connected to the throttle body of the vehicle to provide clean air from the air cleaner to the engine.

An exhaust manifold comprises a plurality of exhaust intake conduits structured to be fluidly coupled to an engine and receive exhaust gas from a corresponding cylinder of the engine. At least one exhaust intake conduit provides a reduction in an exhaust intake conduit cross-sectional area from an inlet to an outlet. A plurality of bends are each defined by a respective one of the exhaust intake conduit outlets. An exhaust intake manifold is fluidly coupled to the exhaust intake manifold and defines an exhaust intake manifold flow axis. Each of the plurality of bends is shaped so as to define an angle of approach of exhaust gas flowing therethrough. A first angle of approach of the first bend relative to the exhaust intake manifold flow axis is smaller than a second angle of approach of an inner second bend.

An intake device for an internal combustion engine configures a flow passage for intake air that is drawn into combustion chambers. The intake device includes an intake manifold configuring multiple runners that respectively distribute intake air to multiple cylinders, a surge tank including a cavity that is connected to the runners and defines a convergence portion, a throttle body incorporating a throttle valve, and a connection pipe connecting the surge tank and the throttle body and configuring a curved flow passage extending between the throttle body and the surge tank. The connection pipe includes a partition plate that divides the curved flow passage into a circumferentially inner flow passage and a circumferentially outer flow passage.

An airflow modifier device for reducing air velocity fluctuations in a multi-throttle internal combustion engine. The device includes: first and second air input ports for receiving respective first and second airflows outputted from respective first and second throttles; first and second air output ports for providing air from one or both of the airflows to manifold input ports of a pair of intake air manifolds; and first and second passageways respectively connecting the first air input port with the first air output port and the second air input port with the second air output port. The airflow modifier device further includes a central passageway interconnecting the first and second passageways so that air entering the first and second air input ports can move between the first and second passageways and can thereby reduce air flow velocity fluctuations at flow sensors located in the airflows upstream of the airflow modifier device.

A two-wheeled vehicle includes a frame assembly having a front end and a rear end extending along a longitudinally-extending centerline, a front ground-engaging member operably coupled to the front end of the frame assembly at a front rotational axis, and a rear ground-engaging member operably coupled to the rear end of the frame assembly at a rear rotational axis. The vehicle further includes an engine supported by the frame assembly and operably coupled to the front and rear ground-engaging members, and the engine includes a throttle body assembly. Additionally, the vehicle includes an air intake assembly fluidly coupled to the engine and including an airbox and a mounting plate having a first channel and a second channel. The first and second channels are configured to align with the throttle body assembly. The mounting plate is configured to couple the airbox to the throttle body assembly.

An engine includes an intake, an air-fuel path coupled to the intake, an accumulator configured coupled to the air-fuel path and configured to store an air-fuel mixture, and at least one valve configured to selectively provide the air-fuel mixture from the engine to the accumulator at a first time and store the air-fuel mixture within the accumulator at a second time. A controller may be configured to provide commands to the at least one valve. The plurality of commands may include an open command to release air and fuel mixture from the accumulator and a close command to store air and fuel mixture in the accumulator.

A two-wheeled vehicle includes a frame assembly having a front end and a rear end extending along a longitudinally-extending centerline, a front ground-engaging member operably coupled to the front end of the frame assembly at a front rotational axis, and a rear ground-engaging member operably coupled to the rear end of the frame assembly at a rear rotational axis. The vehicle further includes an engine supported by the frame assembly and operably coupled to the front and rear ground-engaging members, and the engine includes a throttle body assembly. Additionally, the vehicle includes an air intake assembly fluidly coupled to the engine and including an airbox and a mounting plate having a first channel and a second channel. The first and second channels are configured to align with the throttle body assembly. The mounting plate is configured to couple the airbox to the throttle body assembly.

An intake duct for an internal combustion engine includes a tubular side wall made of a fibrous molded body. The side wall includes split bodies that are separate from one another in a circumferential direction of the side wall. Flanges respectively protrude outward from opposite ends in the circumferential direction of each of the split bodies. Each of the flanges includes a low-compression portion and a high-compression portion that is located inward from the low-compression portion. Each of the flanges of each of the split bodies is paired with and in contact with one of the flanges of a corresponding one of the split bodies. A joining portion made of a plastic material is arranged on parts of each pair of the flanges in contact with each other, the parts being located outward from the high-compression portions, the joining portion surrounding and joining the parts to each other.

To provide an intake manifold which can reliably prevent the step from being formed in the inner wall surface of the intake passage (15) while having provided therein the fitting holding portion (32) for fitting and holding the flame arrester (25) in the axial direction, the intake manifold (10) includes a base member (21), a cover member (22) and a flame arrester (25) having a flame suppression structure. Between the flame arrester (25) and the radical stepped surface (31b) of the recessed body portion (31) is provided a retaining rectifying member (23) that prevents the flame arrester (25) from coming off with respect to the fitting holding portion (32) and forms a third inner peripheral surface (23a) continuous without a step from an opening portion on the other end side (25b) of the flame arrester (25) to the base side second inner wall surface (31c).