Check valves, Venturi devices and engines that include the check valves are disclosed. The check valves define an internal cavity having a first port and a second port, a first seat and a second seat, and a translatable seal disk. The first seat is proximate the first port and has a first annular seal bead, and a second annular seal bead radially inward from the first annular seal bead. The seal disk has a first sealing portion seatable against the first annular seal bead and a second sealing portion seatable against the second annular seal bead (both of a first thickness), an intermediate portion between the first and second sealing portions of a second thickness, and a lip portion defining the outer periphery of the seal disk of a third thickness. The second thickness is greater than the first thickness, and the third thickness is less than the first thickness.

Check valves are disclosed and include a housing defining an internal cavity having a first seat and a second seat, and a seal member within the internal cavity translatable between a closed position against the first seat and an open position against the second seat. The second seat has a middle axis transverse to a plane of a longitudinal cross-section of the housing and has a shortest finger positioned to either the left or to the right of the middle axis. The seal member is seatable against the second seat at an angle or in a deflected position against the plurality of fingers, thereby defining a longer distance of travel to reach the closed position for a portion of the check valve disc that is associated with the position of the shortest finger relative to other portions of the check valve disc.

To provide a compact intake manifold which can easily and reliably hold the flame arrester (25) to the base member, the base member (21) having the flame arrester (25) incorporated therein has the recessed body portion (31) and the annular fitting holding portion (32) for fitting the flame arrester (25) in the axial direction. The fitting holding portion (32) includes an abutment surface (32a) and a fitting inner wall peripheral surface (32b). The flame arrester (25) includes a flame suppressing structure (26), an outer cylinder body (27) surrounding the flame suppression structure (26), and an elastic holder member (51) which covers the outer peripheral surface and both end faces of the outer cylindrical body (27). The elastic holder member (51) has an outer peripheral fitting portion (52) fitted to the fitting holding portion (32) while being held in close contact with the outer cylindrical body (27).

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).

Bypass check valves, suitable for bypassing a Venturi gap, are disclosed and include a housing defining an internal cavity having a first seat and a second seat, and a seal member within the internal cavity translatable between a closed position against the first seat and an open position against the second seat. The second seat defines a support structure having a middle region of a predetermine height and a downstream side having a height that is shorter than the predetermined height of the middle region. The seal member is seatable against the second seat with a downstream portion thereof a further distance from the first seat than an upstream portion thereof.

Check valves, Venturi devices and engines having such check valves, define an internal cavity having a first port and a second port, a first seat and a second seat, and a translatable seal disk. The check valves have an outlet conduit extending from the second port and/or the first seat has a first annular seal bead and a second annular seal bead disposed radially inward of the first annular seal bead with a plurality of ribs extending between the first annular seal bead and the second annular seal bead within the fluid flow path of the first port. The outlet conduit defines an outlet passageway having a restrictor profile that is circular in a transverse profile, and the ribs decrease the flow area of the fluid flow path of the first port by about 10% to about 60%.

An amount of air taken into an air leading type two-stroke engine is increased to enhance an engine output, and gas emission characteristic deterioration caused by blow-back is inhibited. An inhibition member 16 is disposed between a choke valve 4 in a full open position and a throttle valve 6 in a full open position. The inhibition member 16 includes, for example, a mesh member like a metal mesh. Mixed fuel containing oil is supplied to the air-fuel mixture channel 14. Numerous pores of the inhibition member 16 (mesh member) are occluded by a membrane of oil components of the mixed fuel. Consequently, entry of a blow-back flow of an air-fuel mixture from the air-fuel mixture channel 14 into the air channel 12 through the numerous pores of the flow inhibition member 16 (mesh member) can be inhibited.

An air intake assembly for a vehicle includes a vehicle-forward air intake inlet, an airflow diverter opening, and a moisture-diverting gutter surrounding a portion of the vehicle-forward air intake inlet. The moisture-diverting gutter may surround at least a top and opposed sides of the vehicle-forward air intake inlet. The assembly further includes an air intake inlet shield which may define a slope. The airflow diverter opening may be positioned below the vehicle-forward air intake inlet.

A pressuring system for a vehicle engine includes an intake manifold into which ambient gases flows. A control valve connects to the intake manifold. An engine block connects to the intake manifold and connected to a gases outlet. A timing belt cover connects to the engine block. A gases pipe connects between the control valve and the timing belt cover.

A stratified scavenging two-stroke engine includes a first scavenging passage that extends from a first scavenging intake that opens to the inside of the crankcase to a scavenging port that opens to the inside of a cylinder, and a second scavenging passage that branches from the first scavenging passage and extends to a second scavenging intake that opens to the inside of the crankcase. An air passage is provided to supply air for pre-scavenging into the first scavenging passage at a position closer to the first scavenging intake than a position at which the second scavenging passage branches from the first scavenging passage. A first check valve inhibits a flow of air from the first scavenging passage during an upward stroke of the piston, and a second check valve inhibits a flow of air and a gaseous mixture from the first scavenging passage during a downward stroke of the piston.