To allow an intake negative pressure to directly act on a fuel outlet formed on a nozzle tube, and to guide a fuel discharged from the fuel outlet in the nozzle tube to the fuel-air mixture passage. A rotary carburetor (200) has a guide plate member (42) downstream of a fuel outlet (30) located in a through-hole (14). The guide plate member (42) has both side edges (42b) away from an inner wall surface (14a) of the through-hole (14). The through-hole (14) is divided by the guide plate member (42) into a first passage portion (44) and a second passage portion (46). The first passage portion (44) communicates through a piston groove with a scavenging passage of a cylinder. The fuel discharged from the fuel outlet (30) is guided by the guide plate member (42) to the second passage portion (46) and is supplied through the second passage portion (46) to a fuel-air mixture passage (24) of an engine intake system.

A suction tube unit connected between a cylinder block and a carburetor in a stratified scavenging engine has a suction tube for mixture made of an elastic material; and a suction tube for stratified scavenging air made of an elastic material. The suction tube for mixture and the suction tube for air have, at respective inlet ends connected to the carburetor, respective wall portions which face each other and have complementary shapes. A clearance space is provided between the wall portions of the suction tube for mixture and the suction tube for air.

The present invention is to prevent mixing of fresh air and an air-fuel mixture when a throttle valve is fully opened and increase a delivery ratio. A main nozzle (30) is surrounded by a tunnel-like air flow guiding member (52). The air flow guiding member (52) is opened at its front and back sides. A whole amount of fuel discharged via a main nozzle (30) is sent to a downstream side by an air flow created by the air flow guiding member (52). When a throttle valve (22) and a choke valve (24) are both in a fully-opened state, fresh air flows into an air-fuel mixture passage (12) through a gap between these valves (22, 24).

A suction tube of a stratified scavenging engine that can improve the flexibility in designing the shapes and layouts of an air-fuel mixture passage and an air passage; allow for continuous and smooth changes in the shapes of the cross sections of the air-fuel mixture passage and the air passage from the inlet side toward the outlet side; reduce the number of components; and facilitate attachment and assembly; and that is also advantageous in terms of cost is provided. The suction tube includes an air-fuel mixture passage and an air passage, inlet and outlet sides of the passages being connected to a carburetor and a cylinder, respectively; a cylindrical exterior member that mainly forms an outer perimeter portion of each of the air-fuel mixture passage and the air passage; and an interior member for dividing the inside of the cylindrical exterior member into the air-fuel mixture passage and the air passage. With the use of elastic deformation of the interior member or the cylindrical exterior member, the interior member is attached to and integrally formed with the inside of the cylindrical exterior member.

A carburetor for a hand-guided power tool has a carburetor housing and a carburetor rotor supported rotatably in the carburetor housing about an axis of rotation. A needle is disposed on the carburetor rotor and projects into a fuel opening of the carburetor. An adjusting element is operatively connected to the needle so as adjust a position of the needle relative to the carburetor rotor. The adjusting element has an engagement contour that is to be engaged by a tool for adjusting the adjusting element. A securing contour that is fixedly connected to the carburetor rotor is provided. The securing contour, at any point of the securing contour, has a spacing to the axis of rotation of at least approximately 10 mm.

To allow an intake negative pressure to directly act on a fuel outlet formed on a nozzle tube, and to guide a fuel discharged from the fuel outlet in the nozzle tube to the fuel-air mixture passage. A rotary carburetor (200) has a guide plate member (42) downstream of a fuel outlet (30) located in a through-hole (14). The guide plate member (42) has both side edges (42b) away from an inner wall surface (14a) of the through-hole (14). The through-hole (14) is divided by the guide plate member (42) into a first passage portion (44) and a second passage portion (46). The first passage portion (44) communicates through a piston groove with a scavenging passage of a cylinder. The fuel discharged from the fuel outlet (30) is guided by the guide plate member (42) to the second passage portion (46) and is supplied through the second passage portion (46) to a fuel-air mixture passage (24) of an engine intake system.

The intake structure for an internal combustion engine includes: a collision surface configured to face an inlet of a carburetor; a deflecting surface configured to deflect a blowback flow, which is to diffuse after colliding against the collision surface, in one direction along the collision surface; a receiving surface configured to receive the blowback flow deflected by the deflecting surface; and a fuel-accumulating surface formed below the collision surface. A first clearance between an air-guiding direction distal end of the deflecting surface and the receiving surface is brought into communication to a downstream side of a filter of an air cleaner in a fresh-air intake direction so as to act as a main intake passage for fresh air.

A method for controlling a two-stroke engine operatively connected to a turbocharger, the turbocharger being in fluid communication with the engine to provide a boost pressure thereto. The method includes determining an exhaust temperature representative of an actual temperature of exhaust gas being discharged by the engine; determining a temperature difference between the exhaust temperature and a threshold temperature; in response to the exhaust temperature being less than the corresponding threshold value: determining a corrective amount of boost pressure to add to the boost pressure of the turbocharger, the corrective amount of boost pressure being determined based on the temperature difference; and controlling the turbocharger to increase the boost pressure of the turbocharger by the corrective amount.

Handheld construction equipment may include a crankcase scavenged combustion engine arranged to drive a work tool where a fuel injector is configured to provide a controlled amount of fuel into an air and fuel intake flow of the combustion engine, and where an idling air flow channel is arranged to connect with the air and fuel intake flow of the combustion engine in connection to the fuel injector.