Abstract: A mixing system for a power washer includes an electrically actuated valve communicated with a supply of a working fluid, and having a valve head that is movable between open and closed positions to control the flow rate of the working fluid through an outlet of the valve. The outlet of the valve is communicated with a fluid passage of the power washer to enable flow of the working fluid into a primary fluid and discharge of a mixture of the primary fluid and working fluid from the power washer when the valve is open, and to provide a flow of primary fluid from the power washer when the valve is closed.

Abstract: In at least some implementations, a lamination stack includes a plurality of plates coupled together, each plate including at least one leg that collectively define a leg of the stack, with the leg of the stack arranged so that a wire coil may be arranged on the leg of the stack, and wherein the leg of the stack includes a location feature arranged to facilitate location of the stack relative to an adjacent component. In at least some implementations, the location feature may be integrally formed with at least one of the plates, and may be defined by a projection extending from a free end of at least one leg of the stack.

Abstract: In at least some implementations, a method of operating an ignition system for a combustion engine includes charging an energy storage device during at least a portion of the time when the engine is operating, permitting the level of energy stored on the charge storage device to decrease over time after the engine ceases to operate, determining the energy level on the energy storage device when the engine is restarted after having ceased operating, and setting at least one engine operational parameter as a function of the determined energy level. In at least some implementations, the at least one engine operational parameter may include one or more of: richness of a fuel and air mixture to be delivered to the engine, ignition timing, desired engine idle speed.

Abstract: In at least some implementations, a method of controlling a fuel-to-air ratio of a fuel and air mixture supplied to an engine, includes the steps of determining an engine deceleration event, determining the number of engine revolutions required for the engine speed to decrease from one speed threshold to another speed threshold, comparing the number of engine revolutions determined above against a revolution threshold, and making the fuel and air mixture richer if the number of engine revolutions determined above is greater than the revolution threshold. The method may also include determining if, before the engine stabilized at a stable engine speed (which may be an engine idle speed), the engine speed decreased below the stable engine speed as the engine decelerated to the stable engine speed from a speed above the stable engine speed, and making the fuel and air mixture leaner if the determination is affirmative.

Abstract: In at least some implementations, a coupler for a spark plug includes a body formed from an electrically conductive material and including a first connecting portion defining a first cavity, and a second connecting portion defining a second cavity spaced from the first cavity, and the body includes an intermediate portion physically and electrically coupling the first connection portion and the second connecting portion. In at least some implementations, the first connecting portion is formed from a wire coiled to define the first cavity within the coil. In at least some implementations, the second connecting portion is formed from a wire coiled to define the second cavity within the coil.

Abstract: In at least some implementations, a method of operating an ignition system for a combustion engine includes charging an energy storage device during at least a portion of the time when the engine is operating, permitting the level of energy stored on the charge storage device to decrease over time after the engine ceases to operate, determining the energy level on the energy storage device when the engine is restarted after having ceased operating, and setting at least one engine operational parameter as a function of the determined energy level. In at least some implementations, the at least one engine operational parameter may include one or more of: richness of a fuel and air mixture to be delivered to the engine, ignition timing, desired engine idle speed.

Abstract: In at least some implementations, a fuel supply module includes a reservoir and a fuel pump carried by the reservoir. The reservoir may include a body and a lid that define an internal volume to contain a supply of fuel, and the reservoir may include an inlet through which fuel enters the internal volume and an outlet from which fuel is discharged from the fuel supply module. The fuel pump is carried by the reservoir and has a first inlet communicating with the internal volume to take fuel into the fuel pump from the internal volume and a second inlet spaced above the first inlet relative to the direction of the force of gravity to take fluid or vapors into the fuel pump from the internal volume. The fuel pump includes an outlet from which fluid is discharged for delivery to an engine through the reservoir outlet.

Abstract: In at least some implementations, a method of maintaining an engine speed below a first threshold, includes: (a) determining an engine speed; (b) comparing the engine speed to a second threshold that is less than the first threshold; (c) allowing an engine ignition event to occur during a subsequent engine cycle if the engine speed is less than the second threshold; and (d) skipping at least one subsequent engine ignition event if the engine speed is greater than the second threshold. In at least some implementations, the second threshold is less than the first threshold by a maximum acceleration of the engine after one ignition event so that an ignition event when the engine speed is less than the second threshold does not cause the engine speed to increase above the first threshold.

Abstract: In at least some implementations, a lamination stack includes a plurality of plates coupled together, each plate including at least one leg that collectively define a leg of the stack, with the leg of the stack arranged so that a wire coil may be arranged on the leg of the stack, and wherein the leg of the stack includes a location feature arranged to facilitate location of the stack relative to an adjacent component. In at least some implementations, the location feature may be integrally formed with at least one of the plates, and may be defined by a projection extending from a free end of at least one leg of the stack.

Abstract: —In at least some implementations, a control and communication system for a light-duty combustion engine includes a circuit card, an ignition circuit carried by the circuit card and configured to control an ignition timing of the engine, and a short range wireless communication circuit carried by the circuit card. The communication circuit may include a Bluetooth Low Energy antenna. The ignition circuit may include an ignition capacitor that when drained induces an ignition pulse adapted to fire a spark plug. The system may further include a microprocessor that is coupled to and controls the ignition and communication circuits, and/or a clocking circuit adapted to provide a clocking frequency associated with the timing of the ignition circuit and associated with the communication circuit via a short range wireless communication protocol. The clocking circuit may include a crystal oscillator.

Abstract: In at least some implementations, a coupler for a spark plug includes a body formed from an electrically conductive material and including a first connecting portion defining a first cavity, and a second connecting portion defining a second cavity spaced from the first cavity, and the body includes an intermediate portion physically and electrically coupling the first connection portion and the second connecting portion. In at least some implementations, the first connecting portion is formed from a wire coiled to define the first cavity within the coil. In at least some implementations, the second connecting portion is formed from a wire coiled to define the second cavity within the coil.

Abstract: In at least some implementations, an auxiliary power supply in an ignition system for a light-duty combustion engine includes a first auxiliary winding and a second auxiliary winding coupled in parallel with the first auxiliary winding such that both windings are arranged to provide power to an auxiliary load. The first auxiliary winding may include a greater number of turns than the second auxiliary winding. A ratio of the number of turns in the first auxiliary winding to the number of turns in the second auxiliary winding may be between 1.5:1 and 10:1, the first auxiliary coil and the second auxiliary coil may have between 50 and 2,000 turns, and the first auxiliary coil and the second auxiliary coil are formed from wire between 25 and 45 gauge.

Abstract: A speed regulating circuit in communication with an ignition circuit having a primary coil coupled to an ignition member to cause an ignition event within an engine, the speed regulating circuit being arranged to selectively prevent energy from the primary coil from being discharged to the ignition member to selectively prevent an ignition event. In at least some implementations, the speed regulating circuit includes a bidirectional or bilateral triode thyristor having an anode coupled to the primary coil and an anode coupled to ground, and an input gate that may be selectively actuated to route to ground energy received at the triode thyristor from the primary coil to inhibit transfer of energy from the primary coil to the ignition member. The triode thyristor may be selectively actuated, for example, as a function of engine speed, such as an engine speed above a threshold speed.

Abstract: In at least some implementations, an ignition system for a combustion engine includes analog circuit components arranged to control ignition events at an engine speed below a first threshold of engine speed and a microprocessor to control ignition events at engine speeds higher than the first threshold. Hence, ignition can be controlled at lower engine cranking speeds to facilitate starting the engine at lower engine rotational speeds.

Abstract: A kill switch assembly for an internal combustion engine may include a housing, a first terminal carried by the housing and connected to a ground wire, a second terminal carried by the housing and connected to an engine microcontroller communication wire, and a kill switch. The kill switch may be carried by the housing, electrically connected to the first and second terminals, and manually operable by an operator to change the state of the electric switch to provide an engine stop signal to the engine microcontroller. The assembly may also include an electronic circuit carried by the housing, connected to the first and second terminals, and through the wires communicating with the engine microcontroller.

Abstract: In at least some implementations, a method of controlling a fuel-to-air ratio of a fuel and air mixture supplied to an engine, includes the steps of determining an engine deceleration event, determining the number of engine revolutions required for the engine speed to decrease from one speed threshold to another speed threshold, comparing the number of engine revolutions determined above against a revolution threshold, and making the fuel and air mixture richer if the number of engine revolutions determined above is greater than the revolution threshold. The method may also include determining if, before the engine stabilized at a stable engine speed (which may be an engine idle speed), the engine speed decreased below the stable engine speed as the engine decelerated to the stable engine speed from a speed above the stable engine speed, and making the fuel and air mixture leaner if the determination is affirmative.

Abstract: A power tool may include an engine, a tool driven for movement by the engine, a brake mechanism coupled to the tool, a charge forming device coupled to the engine and a transmission member operably coupled to the brake mechanism and a throttle valve of the charge forming device. The brake mechanism inhibits movement of the tool in an engaged position of the brake mechanism and permits movement of the tool in a disengaged position of the brake mechanism. The charge forming device is coupled to the engine to provide a combustible fuel and air mixture to the engine, and the throttle valve is movable between a first position and a second position. The transmission member is operably coupled to the brake mechanism and the throttle valve so that the throttle valve is moved away from the first position when the brake mechanism is moved to the engaged position.

Abstract: At least some implementations of a method of distinguishing between two loads being driven by an engine, includes the steps of determining engine speed at defined intervals, comparing a second engine speed against a previously determined first engine speed, determining if the second engine speed fits an expected pattern of engine speeds, and counting either the number of incidents where the second engine speed does not fit the expected pattern, or the number of incidents where the second engine speed does fit the expected pattern, or some combination of these two. A method of determining if an engine is operating at least near a lean limit of its air to fuel ratio is also disclosed.

Abstract: An ignition system for a light-duty combustion engine includes a charge winding, a microcontroller and a power supply sub-circuit. The sub-circuit is coupled to both the charge winding and the microcontroller and includes a first power supply switch, a power supply capacitor and a power supply zener. The sub-circuit is arranged to turn off the first power supply switch so that charging of the power supply capacitor stops when the charge on the power supply capacitor exceeds the breakdown voltage on the power supply zener. In at least some implementations, the power supply capacitor may power the microcontroller and the power supply sub-circuit may limit or reduce the amount of electrical energy taken from the induced AC voltage of the charge winding to a level that is still able to sufficiently power the microcontroller yet saves energy for use elsewhere in the system.

Abstract: In at least some implementations, an ignition system for a combustion engine includes analog circuit components arranged to control ignition events at an engine speed below a first threshold of engine speed and a microprocessor to control ignition events at engine speeds higher than the first threshold. Hence, ignition can be controlled at lower engine cranking speeds to facilitate starting the engine at lower engine rotational speeds.