Abstract: An engine-powered work tool includes an engine having a crank shaft, an output controller and a wind governor. The output controller includes an output control shaft angularly rotatable about its axis for controlling a rotation speed of the crank shaft. The wind governor can control the angular rotation of the output control shaft and includes: a governor plate for receiving cooling air generated at a cooling fan connected to the crank shaft; an arm fixed to the output control shaft; and a governor spring connected to the arm for biasing the output control shaft to increase the rotation speed of the crank shaft. The governor plate functions to bias the output control shaft to decrease the rotation speed of the crank shaft upon receipt of the cooling air. The governor spring has an end changeable in position relative to the output controller among a plurality of prescribed positions.

Abstract: An air-cooled general-purpose engine includes: a cooling fan fixed to one end portion, protruding outward from one end wall of an engine main body, of a crankshaft; and a shroud which is mounted to the engine main body, and which defines a cooling-air path between the shroud and the one end wall, the cooling-air path guiding a cooling air blown under pressure from the cooling fan. The air-cooled general-purpose engine includes: an oil pump which pumps up an oil from an oil reservoir; and an oil-supply path which is formed in the one end wall, facing the cooling-air path, of the engine main body, and configured to guide the oil discharged from the oil pump to a valve operating chamber in a head portion of the engine main body, and a jet for jetting the oil is provided in an opening of the oil-supply path, the opening being open to the valve operating chamber.

Abstract: An engine fuel economizer device connected or connectable to establish an electrical path between an electrical system of an engine, preferably a d.c. battery and a starter motor or a charging alternator of an engine, preferably an internal combustion engine. The device, in one aspect thereof, includes a coil of conductive hollow tubing having a plurality of complete turns or loops formed therealong, is positionable over and around a section of fuel line which extends from a fuel tank to the engine. In another aspect of this disclosure, the coil device is prepositioned over and along a length of nonconductive tubing which is spliceable into the fuel line after a section of fuel line is sectioned and removed. Various additional aspects position the device in close proximity to the flow of fuel from the fuel tank to the engine.

Abstract: A cooling fan controller is provided for controlling the revolving speed of a cooling fan that introduces outside air as a cooling wind to cool a fluid being cooled; in order to optimally control the revolving speed if the cooling fan in accordance with load, and to suppress noise caused by the cooling fan. The cooling fan controller includes a fluid temperature sensor 40 for sensing a temperature To of the fluid, an air temperature sensor 30 for sensing a temperature Ta of the air, and a control 20 for calculating a difference between the fluid temperature To sensed by the fluid temperature sensor 40 and the air temperature Ta sensed by the air temperature sensor 30, and setting a target revolving speed Nf of the cooling fan in accordance with a magnitude of the calculated difference.

Abstract: A manually guided implement having an internal combustion engine is provided. A fuel/air mixture is supplied to the internal combustion engine via a diaphragm carburetor. The engine is cooled by a cooling fan that is driven by the internal combustion engine and that generates an air stream. The diaphragm carburetor has a fuel-filled control chamber with a control diaphragm which on that side facing away from the control chamber delimits a compensation chamber. To limit speed, a control pressure line is provided between the compensation chamber and the air stream generated by the cooling fan.

Abstract: An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.

Abstract: The air vane governor has improved speed droop characteristics under no load and light load conditions to prevent engine stumbling. The air vane governor includes a primary spring and a secondary spring; both springs oppose the movement of the air vane at no load and light load conditions. At increased load, the secondary spring drops out. The tension on both springs is adjustable. The added spring force of the secondary spring makes the governor less sensitive at no load and light load, resulting in more even operation, particularly during engine warmup.

Abstract: A floating portable pump is constructed of a float defining a well for containing water, a centrifugal pump supported on the float with its impeller shaft extending vertically and with its suction inlet submerged in water in the well, and an internal combustion engine arranged to drive the pump impeller. The pump and engine are secured together on the float in an arrangement such that the engine causes rotation of the pump impeller to cause the pump to draw water from the well through its suction inlet and discharge water from the pump discharge.

Abstract: Disclosed is a method of controlling the air-fuel ratio of an air-fuel mixture to be supplied to an internal combustion engine. The method employs a feedback control in which the control is made to maintain the air-fuel ratio at the stoichiometric level in accordance with the air-fuel ratio read through the detection of a component of the exhaust gas and, at least during the idling of the engine after the warming up of the same, a lean control in which the control is made to maintain the air-fuel ratio at the leaner side of the stoichiometric level. The lean control is allowed when the mean value of the engine speed over a predetermined period is greater than a predetermined reference value during the idling after warming up of the engine, while the feedback control is conducted when the mean value is below the predetermined reference value. Disclosed also is an apparatus suitable for carrying out this method.

Abstract: The internal combustion engine for a lawn mower or the like includes a carburetor, a throttle member or plate disposed in the carburetor throat and movable between an open position and a flow restricting position, a rotatable shaft carrying the throttle plate and connected to a movable air vane, an engine fan, such as a finned flywheel, for blowing air against the air vane and urging the throttle plate toward a flow restricting position, a torsion spring encircling the throttle shaft with a first end connected thereto for biasing the throttle plate toward the open position and adjustment means connected to the spring for adjusting the biasing force of the spring on the throttle plate. The adjustment means includes a speed control member or lever connected to the second end of the spring and mounted remotely from the throttle shaft for reciprocative movement in a direction transversely of the rotational axis of the throttle shaft between first and second spring force level positions.

Abstract: A method and apparatus for varying the fuel ratio of an air-fuel mixture supplied to the carburetor of an internal combustion engine. In a first embodiment, a valve opens and closes a port in an aluminum block between a passage coupled to the PCV and carburetor and a second passage open to the atmosphere. A spring in the second passage modulates the air flow as a function of vacuum pressure and thermally responsive means maintains the valve closed until the engine reaches its operating temperature. In a second embodiment the valve is opened as a function of the wind pressure produced during vehicle movement.