In at least some implementations, a fuel metering valve, includes a bobbin defining a passage and having one or more voids in the surface of the bobbin that defines the passage, aa wire coil around the bobbin and an armature. The armature is received within the passage in the bobbin and movable relative to the bobbin from a first position to a second position when electricity is supplied to the wire coil.

In at least some implementations, a charge forming device for a combustion engine includes a throttle body and a throttle valve. The throttle body has a throttle bore with an inlet through which air flows into the throttle bore and an outlet from which a fuel and air mixture exits the throttle bore. The throttle bore has a throat between the inlet and outlet and the throat has a reduced flow area compared to at least one of the inlet and outlet. The throttle valve has a valve head received within the throat of the throttle bore and movable relative to the throttle body between a first position and a second position wherein the flow area between the valve head and the throttle body is greater when the valve head is in the second position than in the first position.

In at least some implementations, a fuel metering valve, includes a bobbin defining a passage and having one or more voids in the surface of the bobbin that defines the passage, aa wire coil around the bobbin and an armature. The armature is received within the passage in the bobbin and movable relative to the bobbin from a first position to a second position when electricity is supplied to the wire coil.

In at least some implementations, a charge forming system for a combustion engine includes a first fuel supply device having a first passage from which fuel is discharged for delivery to the engine and a second fuel supply device having a second passage from which fuel is discharged for delivery to the engine. The first passage communicates with the second passage so that the fuel in the first passage is combined with the fuel in the second passage.

In at least some implementations, a charge forming system for a combustion engine includes a first fuel supply device having a first passage from which fuel is discharged for delivery to the engine and a second fuel supply device having a second passage from which fuel is discharged for delivery to the engine. The first passage communicates with the second passage so that the fuel in the first passage is combined with the fuel in the second passage.

In at least some implementations, a charge forming device for a combustion engine includes a throttle body and a throttle valve. The throttle body has a throttle bore with an inlet through which air flows into the throttle bore and an outlet from which a fuel and air mixture exits the throttle bore. The throttle bore has a throat between the inlet and outlet and the throat has a reduced flow area compared to at least one of the inlet and outlet. The throttle valve has a valve head received within the throat of the throttle bore and movable relative to the throttle body between a first position and a second position wherein the flow area between the valve head and the throttle body is greater when the valve head is in the second position than in the first position.

An engine-driven working machine includes a controller, which varies a control value of a solenoid valve so as to decrease or increase an opening degree of the solenoid valve when a rotating speed of an engine is within a predetermined high rotating speed range and the rotating speed of the engine is lower or higher than a predetermined rotating speed, respectively. When the control value of the solenoid valve is varied so as to decrease the opening degree of the solenoid valve and corresponds to a predetermined opening degree larger than a fully-closed state, the control value is set to a limitation value.

An engine-driven working machine includes a controller, which varies a control value of a solenoid valve so as to decrease or increase an opening degree of the solenoid valve when a rotating speed of an engine is within a predetermined high rotating speed range and the rotating speed of the engine is lower or higher than a predetermined rotating speed, respectively. When the control value of the solenoid valve is varied so as to decrease the opening degree of the solenoid valve and corresponds to a predetermined opening degree larger than a fully-closed state, the control value is set to a limitation value.

A carburetor has a carburetor body having a venturi passage that conveys air from an air inlet to an air outlet. A throttle valve controls flow of the air in the venturi passage. The throttle valve is movable into a closed position, an open position, and at least one transition position between the closed position and the open position. A fuel bowl holds fuel for mixing with the air in the venturi passage. A main nozzle discharges the fuel from the fuel bowl to the air in the venturi passage when the throttle is in the open position. A secondary circuit that is smaller than the main nozzle discharges fuel from the fuel bowl to the air in the venturi passage when the throttle is in the closed position, the transition position, and the open position. A filter is configured to remove particulate matter from the fuel in the fuel howl prior to discharge via the secondary circuit. Methods are for making the carburetor and operating the carburetor.