A backpack type blowing apparatus includes an intake pipe that connects an air cleaner fixed to a fan case of an air blower to a carburetor that supplies an evaporated fuel to an engine body, and a top cover fixed to the fan case to cover at least the intake pipe by interposing the intake pipe between the top cover and the fan case. The top cover has a plurality of cover fixing portions fixed to the fan case. An outer circumferential-side fixed portion positioned on an outer circumferential side of the intake pipe in the fan case is included in the plurality of cover fixing portions.

A carburetor achieves better emission characteristics while improving a combustion state by increasing a delivery ratio of a stratified scavenging engine and reducing intake resistance. No dividing wall is provided between a throttle valve 204 and a choke valve 242, and a gap 244 between the valves 204 and 242 is opened. Intake air in both of an upper region and a lower region of the choke valve 242 flows into an air-fuel mixture passage 246 in a lower region of the fully-open throttle valve 204. A main nozzle 202 is arranged so as to be inclined toward the throttle valve 204.

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).

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.

An engine includes an air filter assembly having a filter element and a case. A base of the case includes multiple clips, multiple pins, and a catch. The clips are configured to engage a bottom wall of the filter element. A cover of the case includes multiple hinge wings, a hook, and a guide structure. Each of the hinge wings is coupled with a corresponding pin of the base to allow the cover to rotate about the pins. The hook is configured to fasten to the catch of the base for securing the case in a closed configuration. The guide is configured to facilitate placement of the hook and prevent lateral slipping of the hook from the catch of the base. The base and the cover define an interior volume of the air filter assembly sized to receive the filter element.

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.

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.

An engine includes a breather conduit, an intake conduit, and an air filter assembly. The assembly includes a filter element having a top wall, a bottom wall, a first aperture through the bottom wall, a second aperture through the bottom wall, and filter media extending between the top and bottom walls, wherein the first and second apertures are the same shape, the same size, and are equally spaced apart from the center of the bottom wall. The filter assembly also includes a case. The filter element is configured to be received in the case such that the breather conduit and the intake conduit are directed to and from the interior chamber of the filter element, respectively, whereby air filtered by the filter media mixes with unfiltered gases from the breather conduit in the interior chamber of the filter element prior to entering the intake conduit.

A hand-guided power tool has a power tool housing and an internal combustion engine arranged in the power tool housing and configured to drive a tool member of the power tool. A fuel tank and at least one electric component are provided. A control device that is an electronic control unit is connected to the at least one electric component of the power tool and controls the at least one electric component. The power tool has a top face which, when parking the power tool in a usual parking position on a flat horizontal support surface, is facing upwardly. The electronic control unit is positioned laterally adjacent to the fuel tank device, when viewing the power tool in the usual parking position.

An engine-powered work tool includes an engine having a crank shaft, an ignition system, an output controller having a throttle valve shaft for controlling output of the engine, a wind governor connected to the throttle valve shaft, a rotation speed detector and an ignition control unit. The wind governor includes a governor plate movable upon receipt of cooling air generated by a cooling fan to control an angular rotation of the throttle valve shaft. The rotation speed detector detects a rotation speed of the crank shaft. The ignition control unit controls the ignition system based on the rotation speed of the crank shaft detected by the rotation speed detector to reduce the output of the engine when the rotation speed detector determines that the governor plate exceeds a predetermined position.