A two-stroke engine (1) is disclosed comprising a cylinder (2), a piston (3) arranged to reciprocate in the cylinder (2), a crankcase (5), a fuel injector (7) configured to inject fuel into the crankcase (5), an air inlet (9) connected to the crankcase (5), and a stratified scavenging intake (11) connected to the cylinder (2). The engine (1) comprises a throttle (13) configured to control the amount of air supplied to the air inlet (9) and to the stratified scavenging intake (11). The present disclosure further relates to handheld power tool (50) comprising an engine (1).

An elastic connecting support for arrangement between a combustion engine and an air filter of a handheld work apparatus is disclosed. The connecting support has a first channel for largely fuel-free air and a second channel for a fuel/air mixture. The connecting support is realized as a single piece, and has, on a first side, an engine connecting flange, at which the first and second channel end, for connection to the combustion engine. The first channel has a first peripheral wall and the second channel has a second peripheral wall. The first peripheral wall and the second peripheral wall are arranged at a distance in relation to each other in a longitudinal section of the connecting support. The channels extend from the first side to a second side of the connecting support. On the second side, the first channel and the second channel end at a common connecting flange.

An internal combustion engine (10) fitted with a carburetor (40) is provided with a fire-resistant cover member (62) having a front wall (65A) facing an air inlet port (44) of the carburetor, and a breather tube (60) having an inlet end (60A) connected to a crank chamber (28) of the internal combustion engine main body, and an outlet end (60B) supported by the cover member at a position located between the front wall and the carburetor.

An internal combustion engine (10) fitted with a carburetor (40) is provided with a fire-resistant cover member (62) having a front wall (65A) facing an air inlet port (44) of the carburetor, and a breather tube (60) having an inlet end (60A) connected to a crank chamber (28) of the internal combustion engine main body, and an outlet end (60B) supported by the cover member at a position located between the front wall and the carburetor.

A carburetor for the combustion engine in a handheld work apparatus has a carburetor housing in which a carburetor drum is mounted rotatably about a pivot axis. The carburetor drum has a drum body which has at least one channel which runs transversely with respect to the pivot axis and forms an intake channel portion. A sensing unit for sensing at least one rotational position of the carburetor drum is provided. The sensing unit includes a control contour and a sensing device interacting with the control contour. The control contour is formed on the carburetor drum. A method for operating a combustion engine makes provision for the control device to control the supplied quantity of fuel depending on the rotational position, sensed by the sensing unit, of the carburetor drum.

An air box assembly attached to an outdoor power tool for reducing sound generated by an engine is provided. The air box assembly includes a casing formed as an upper and lower housing attached to each other to define an enclosed space. The casing includes at least one air inlet and an air outlet. At least one filter is positioned within the casing. An air guide assembly is positioned within the casing such that the flow of air to the engine passes through the air guide assembly as it travels to the engine and sound from the engine passes through the air guide assembly as it exits the air box assembly. The air guide assembly includes a plurality of fluid pathways therein, wherein the fluid pathways are in fluid communication with the air outlet of the air box assembly.

A first fuel storage portion is disposed on the upstream side of a fuel supply device of an engine so as to be contiguous with an air-intake passage of the fuel supply device. A blow-back suppression plate for suppressing blow-back from the air-intake passage is disposed between a filter element and the first fuel storage portion of an air cleaner. A suction-back passage is formed such that fuel accumulated in a fuel accumulation portion in the air cleaner is suctioned back through the suction-back passage into the air-intake passage. The suction-back passage allows communication between the fuel accumulation portion in the air cleaner and a suction-back port formed at the downstream-side end of the first fuel storage portion.

An elastic connecting support for arrangement between a combustion engine and an air filter of a handheld work apparatus is disclosed. The connecting support has a first channel for largely fuel-free air and a second channel for a fuel/air mixture. The connecting support is realized as a single piece, and has, on a first side, an engine connecting flange, at which the first and second channel end, for connection to the combustion engine. The first channel has a first peripheral wall and the second channel has a second peripheral wall. The first peripheral wall and the second peripheral wall are arranged at a distance in relation to each other in a longitudinal section of the connecting support. The channels extend from the first side to a second side of the connecting support. On the second side, the first channel and the second channel end at a common connecting flange.

A simple engine, comprises (1) a cylinder and a spark plug in the cylinder; (2) a carburetor, fluidly connected to the cylinder; (3) a primary air intake path, fluidly connecting atmosphere to the carburetor; (4) a carburetor bypass air intake path, fluidly connecting air to the cylinder without passing through the carburetor; and (5) a valve, along the carburetor bypass air intake path, for controlling the flow of air through the carburetor bypass air intake path.

An internal combustion engine (10), including a cylinder (15) with a cylinder wall (12) defining a combustion chamber (32), a piston (13) reciprocally disposed within the combustion chamber (32) a crankcase (16) including a crankshaft (11) rotatably disposed therein, the piston (13) being connected to the crankshaft (11) by a connecting rod (17), a first scavenger duct (3) extending between the combustion chamber (32) and the crankcase (16), the first scavenger duct (3) including a top port (31a) and a bottom port (31b), a fuel and air inlet channel (22) in fluid communication with the crankcase (16) by way of a piston ported fuel and air inlet port (23) so that the fuel and air inlet channel (22) delivers a fuel and air mixture to the crankcase (16), and an airhead channel (6) in fluid communication with the first scavenger duct (3) by way of a first piston ported air inlet port (7), characterized in that the fuel and air inlet channel (22) is in fluid communication with the airhead channel (6) so that the fuel and air mixture is combinable with the air flow from the airhead channel (6).