An internal combustion engine includes an engine body defining a combustion chamber, an ignition device configured to ignite mixture in the combustion chamber, an operation device configured to receive a stop operation to stop the internal combustion engine, a controller configured to stop the ignition device from igniting the mixture in response to reception of the stop operation by the operation device, a carburetor configured to supply fuel to an intake passage that communicates with the combustion chamber, a switching valve provided in the intake passage, and an adjustment device configured to adjust an opening degree of the switching valve, wherein the adjustment device is configured to close the switching valve in conjunction with the reception of the stop operation by the operation device.

A system for combusting volatile vapors includes a carburetor having intake valves for receiving base fuel from a fuel source, ambient combustion air, and volatile vapors from a vapor source. A plurality of sensors measure and generate sensor data based on a respective plurality of physical properties associated with the carburetor and associate combustion engine operation. One or more programmable controllers receive the sensor data and control the intake valves to regulate respective ratios of the fuel, air, volatile vapors drawn through the carburetor based on the received sensor data. To increase the burn of volatile vapors, an engine loading system automatically operated by the controller(s) applies an automatically adjustable braking load on the engine. The load level applied is based on the sensor data and commensurate with maintaining stable engine running conditions. The loading system decreases time necessary to remediate a site.

An engine is configured such that, during the starting of the engine, when it is being detected that throttle opening has been set at a starting position, if it is detected that the engine speed has exceeded a predetermined speed slightly lower than a speed when a centrifugal clutch becomes an engaged state, a control unit retards the ignition timing from a general angle to a first angle BTDC, and then advances the ignition timing to a second angle at predetermined intervals, and holds the ignition timing at the second angle for a predetermined time period, thereby preventing the engine from stopping due to fouling on the spark plug while suppressing the engine speed at the speed when the centrifugal clutch becomes the engaged state, or less.

To meet stringent emission standards and improve performance of two-stroke crankcase-scavenged engines, the muffler (13) of the engine is provided with mixing means (130, 31) for mixing the exhaust gases (42) resulting from the mixture participating in combustion and gases resulting from scavenging, so that a substantially homogenous gaseous mixture is formed within the muffler (13), and means (81) for sensing oxygen concentration is located in the homogeneous gaseous mixture and are configured to provide an output value to a control unit (80) for controlling supply of fuel to the engine and thereby the air-fuel ratio in the combustion chamber (41). The muffler (13) suitably is provided with a catalytic element (140), preferably a three-way catalyst. The engine (1) preferably is a stratified charge engine.

The present disclosure relates to a carburetor assembly (7) comprising a control unit (17), an air channel (8), a throttle valve (9), a choke valve (10), a pulsed fuel valve (11), and a fuel supply line (12). The control unit (17) is adapted to control the fuel valve (11) to supply fuel in accordance with a certain start setting, where the choke valve (10) can be open or closed. The carburetor assembly (7) comprises a rotation angle detector assembly (20) with a choke detector part (29) that is mounted to a choke shaft (30) that is connected to the choke valve (10) such that the choke detector part (29) is arranged to rotate together with the choke valve (10). The rotation angle detector assembly (20) further comprises a choke sensor device (23, 33) that is connected to the control unit (17) and can be affected by the choke detector part (29) such that the choke sensor device (23, 33) provides different output signals to the control unit (17) in dependence of whether the choke valve (10) is open or closed.

A two-stroke engine (4) has a throttle motor (22) for driving a throttle valve (20), a fuel injection device (430) disposed in an intake system (18) including a crank chamber (420), and a control unit (24) controlling the throttle motor (22) and the fuel injection device. The two-stroke engine (4) is designed to achieve an engine rotation speed of 4,500 rpm to 7,000 rpm when the throttle valve (20) is fully open. The two-stroke engine (4) is operated with the throttle full open by the control unit (24), and a battery (8) is charged with electric power generated by a generator (6) using the two-stroke engine.

A two-stroke engine (4) has a throttle motor (22) for driving a throttle valve (20), a fuel injection device (430) disposed in an intake system (18) including a crank chamber (420), and a control unit (24) controlling the throttle motor (22) and the fuel injection device. The two-stroke engine (4) is designed to achieve an engine rotation speed of 4,500 rpm to 7,000 rpm when the throttle valve (20) is fully open. The two-stroke engine (4) is operated with the throttle full open by the control unit (24), and a battery (8) is charged with electric power generated by a generator (6) using the two-stroke engine.

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.

Present embodiments provide a throttle body which may be used with a variety of engines of different manufacturers. The throttle body includes an inlet which expands to two or more bores, which extend downwardly through the throttle body. The throttle body may provide improved fuel pathways and fuel injector placement.

A garden tool includes a gasoline engine and a power source, the gasoline engine including a fuel supply system and an ignition system. The garden tool may further include a control system with at least one sensor used for collecting a working condition signal of the gasoline engine and a controller used for receiving the working condition signal and controlling the fuel supply system and/or the ignition system according to the working condition signal received. The power source may provide a power supply for the fuel supply system, the ignition system, and the control system through the controller.