Abstract: According to one implementation, carburetor includes an intake bore, a throttle valve, a main fuel nozzle, an accelerator device and a fuel passage. The throttle valve is movable between an idle and wide open positions and includes a shaft rotatably supported around an axial line extending across the intake bore. The accelerator device may be operable to increase an amount of fuel that flows through the main fuel nozzle when the throttle valve is moved toward its wide open position, and may include a fuel reservoir constructed and arranged to store fuel. The fuel passage communicates with the main fuel nozzle and the fuel reservoir is provided upstream of the main fuel nozzle such that fuel flows through the fuel reservoir before being delivered to the main fuel nozzle.

Abstract: A carburetor fuel adjustment assembly includes a low speed needle valve and preferably a high speed needle valve threaded into respective receptacles of a carburetor body. Each receptacle defines an elongated cavity which intersects a fuel passage and has a valve orifice or seat. Each needle valve has a shank which threadably engages the respective receptacles and a tip that extends into the axially-aligned orifice or seat. The tip is axially movable relative to the orifice by rotation of the needle valve to control the size of the opening between the valve and orifice for fuel flow. A resilient body cooperates with the valve shank in laterally biasing the tip into a steadfast position relative to the orifice or seat. The lateral bias assures constant area for fuel flow through the orifice by resisting needle movement until a sufficient torque is intentionally applied to the needle valve.

Abstract: A control system for a low cost, light duty combustion engine, where the control system generally utilizes engine speed and/or temperature input signals and independent operating sequences to determine a desired ignition timing and air-to-fuel ratio for a combustible mixture. There are several independent operating sequences, each one of which is designed to optimally control the engine under certain conditions. These operating sequences include a Cranking sequence that commences after the engine is initially turned on, a Warm Up sequence which follows the Cranking sequence, a Normal Mode sequence for typical operating conditions, an Acceleration sequence for certain increases in engine speed, a Come Down sequence for when a sufficient engine speed is followed by a certain decrease in speed, and a Recovery Bump sequence for when the engine speed dips below a predetermined level.

Abstract: A control system for a low cost, light duty combustion engine, where the control system generally utilizes engine speed or engine speed and temperature input signals and independent operating sequences to determine a desired ignition timing and air-to-fuel ratio for a combustible mixture. There are several independent operating sequences, each one of which is designed to optimally control the engine under certain conditions.