An apparatus and a method are provided for a crankcase breather vent assembly to direct blow-by gases out of an engine crankcase. A vent base comprising a generally cylindrical vessel communicates received blow-by gases into an interior cavity of a breather vent that comprises a filter medium. Baffles disposed within an interior cavity of the vent base capture oil carried along with the blow-by gases. The captured oil is directed to an oil sump of the engine by way of a suitable hose. A bonnet fastenably receives the breather vent and is configured to reduce a buildup of oil residue on nearby engine components. An outer profile of the breather vent is tapered along a longitudinal dimension of the filter medium to facilitate unrestricted air flow through the filter medium when the bonnet is installed onto the breather vent.

An apparatus and a method are provided for a crankcase breather vent assembly to direct blow-by gases out of an engine crankcase. A vent base comprising a generally cylindrical vessel communicates received blow-by gases into an interior cavity of a breather vent that comprises a filter medium. Baffles disposed within an interior cavity of the vent base capture oil carried along with the blow-by gases. The captured oil is directed to an oil sump of the engine by way of a suitable hose. A bonnet fastenably receives the breather vent and is configured to reduce a buildup of oil residue on nearby engine components. An outer profile of the breather vent is tapered along a longitudinal dimension of the filter medium to facilitate unrestricted air flow through the filter medium when the bonnet is installed onto the breather vent.

A two-wheeled vehicle includes a frame, a plurality of ground-engaging members for supporting the frame, and an engine supported by the frame and operably coupled to the ground-engaging members. Additionally, the two-wheel vehicle includes a down tube extending downwardly from a front end of the frame. A front fairing is supported on the down tube.

A two-wheeled vehicle includes a frame, a plurality of ground-engaging members for supporting the frame, and an engine supported by the frame and operably coupled to the ground-engaging members. Additionally, the two-wheel vehicle includes a down tube extending downwardly from a front end of the frame. A front fairing is supported on the down tube.

Systems are provided for a crankcase ventilation system. In one example, a crankcase ventilation (CCV) system for an engine configured to transmit crankcase gases into a clean side air duct, the clean side air duct comprising a sensor and a crankcase ventilation spigot, wherein the crankcase ventilation spigot is configured to be disposed downstream of the sensor, the crankcase ventilation spigot having an outlet configured to direct crankcase gases emerging from the crankcase ventilation spigot away from the sensor.

An abnormality determination device of an internal combustion engine in which a breather line connects an intake-air path positioned upstream from a forced-induction system and a crankcase includes an intake-air flow rate sensor that detects an intake air flow rate in the intake-air path, a pressure sensor that detects a pressure of the breather line, and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit estimates an intake air resistance of the intake-air path from the pressure when the engine is under low load conditions under which the intake air flow rate is less than a predetermined value and the pressure when the engine is under high load conditions under which the intake air flow rate is the predetermined value or greater and determines abnormality of the breather line when the intake air resistance is less than a threshold.

An abnormality determination device of an internal combustion engine in which a breather line connects an intake-air path positioned upstream from a forced-induction system and a crankcase includes an intake-air flow rate sensor that detects an intake air flow rate in the intake-air path, a pressure sensor that detects a pressure of the breather line, and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit estimates an intake air resistance of the intake-air path from the pressure when the engine is under low load conditions under which the intake air flow rate is less than a predetermined value and the pressure when the engine is under high load conditions under which the intake air flow rate is the predetermined value or greater and determines abnormality of the breather line when the intake air resistance is less than a threshold.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

A crankcase ventilation system is disclosed that includes a PCV valve, a spigot and a tube connector. The PCV valve is enclosed in a module housing that encloses a plunger, and a spring. The module housing defines an inlet opening, and an outlet opening and is assembled inside an engine component. The spigot is attached to an outer surface of the engine and is in fluid communication with the PCV valve through the outlet opening. The tube connector is in fluid communication with the tube connector and the PCV valve. An intake manifold of the engine provides vacuum to the PCV valve, through the tube, the tube connector and the spigot. If one of the tube, tube connector, or spigot is detached from the engine, the PCV valve is retained in the engine and is held closed by the spring biasing the plunger against the inlet opening.