A general purpose engine includes: a cooling fan fixed to an engine rotary shaft; a muffler to silence exhaust gases; a muffler covering to cover the muffler; and an auto choke device to control an opening of a choke valve in an air intake passage by the utilization of heat evolved from the muffler. The auto choke device includes: a drive source, which is fitted to the muffler covering in a non-contact fashion to the muffler and exposed to an outer surface of the muffler covering; and a link member to connect between the drive source and the choke valve. The drive source includes a bracket, which is fitted to the muffler covering, and a bimetal fitted inside the bracket. The bracket includes a heat shield extending towards an inner side of the muffler covering, and the heat shield blocks out a cooling wind then flowing towards the bimetal.

An injection hole has an injection hole passage communicating an inner opening with an outer opening. The inner opening is smaller than the outer opening in cross-sectional area. The needle moves in a valve closing direction to abut against a valve seat to restrict a flow of fuel through the injection hole. A first inner wall of the injection hole is located on a valve closing direction side relative to an injection hole axis. A second inner wall of the injection hole is located on an opposite side of the injection hole axis from the valve closing direction side. The injection hole passage is defined by the first inner wall and the second inner wall.

An integrated ignition and electronic auto-choke module for an internal combustion engine and an internal combustion engine including the same. In one aspect, the module includes a housing that is configured to be mounted to an engine block of an internal combustion engine. The housing may contain at least a portion of a first temperature sensor that measures a first temperature indicative of an engine temperature. The housing may also contain a controller and at least a portion of an ignition circuit. The controller may be coupled to the first temperature sensor and configured to determine a starting position of a choke valve based on the first temperature and operate an actuator to move the choke valve into the starting position accordingly.

An integrated ignition and electronic auto-choke module for an internal combustion engine and an internal combustion engine including the same. In one aspect, the module includes a housing that is configured to be mounted to an engine block of an internal combustion engine. The housing may contain at least a portion of a first temperature sensor that measures a first temperature indicative of an engine temperature. The housing may also contain a controller and at least a portion of an ignition circuit. The controller may be coupled to the first temperature sensor and configured to determine a starting position of a choke valve based on the first temperature and operate an actuator to move the choke valve into the starting position accordingly.

The invention concerns a method for controlling the fuel supply to an internal combustion engine at start-up. The fuel supply system can be set in at least two start modes, a lean mode and a rich mode, and the selection of mode is based on an evaluation of a previous start attempt or successful run. The invention also concerns a carburetor (10) having a fuel supply system including a main fuel path (13) with an actively controlled fuel valve (26) and an idling fuel path (14) branching off from the main fuel path (13) downstream of the valve (26). The fuel supply system further includes a start fuel line (23, 423) starting upstream (FIG. 1) or downstream (FIG. 4) of the fuel valve (26) and ending in at least one start fuel outlet near and downstream of a choke valve.

The invention concerns a method for controlling the fuel supply to an internal combustion engine at start-up. The fuel supply system can be set in at least two start modes, a lean mode and a rich mode, and the selection of mode is based on an evaluation of a previous start attempt or successful run. The invention also concerns a carburetor (10) having a fuel supply system including a main fuel path (13) with an actively controlled fuel valve (26) and an idling fuel path (14) branching off from the main fuel path (13) downstream of the valve (26). The fuel supply system further includes a start fuel line (23, 423) starting upstream (FIG. 1) or downstream (FIG. 4) of the fuel valve (26) and ending in at least one start fuel outlet near and downstream of a choke valve.

A general purpose engine includes: a cooling fan fixed to an engine rotary shaft; a muffler to silence exhaust gases; a muffler covering to cover the muffler; and an auto choke device to control an opening of a choke valve in an air intake passage by the utilization of heat evolved from the muffler. The auto choke device includes: a drive source, which is fitted to the muffler covering in a non-contact fashion to the muffler and exposed to an outer surface of the muffler covering; and a link member to connect between the drive source and the choke valve. The drive source includes a bracket, which is fitted to the muffler covering, and a bimetal fitted inside the bracket. The bracket includes a heat shield extending towards an inner side of the muffler covering, and the heat shield blocks out a cooling wind then flowing towards the bimetal.

An integrated ignition and electronic auto-choke module for an internal combustion engine and an internal combustion engine including the same. In one aspect, the module includes a housing that is configured to be mounted to an engine block of an internal combustion engine. The housing may contain at least a portion of a first temperature sensor that measures a first temperature indicative of an engine temperature. The housing may also contain a controller and at least a portion of an ignition circuit. The controller may be coupled to the first temperature sensor and configured to determine a starting position of a choke valve based on the first temperature and operate an actuator to move the choke valve into the starting position accordingly.

An integrated ignition and electronic auto-choke module for an internal combustion engine and an internal combustion engine including the same. In one aspect, the module includes a housing that is configured to be mounted to an engine block of an internal combustion engine. The housing may contain at least a portion of a first temperature sensor that measures a first temperature indicative of an engine temperature. The housing may also contain a controller and at least a portion of an ignition circuit. The controller may be coupled to the first temperature sensor and configured to determine a starting position of a choke valve based on the first temperature and operate an actuator to move the choke valve into the starting position accordingly.

A carburetor has a housing wherein a control drum is rotatably mounted. A section of an intake channel is formed in the carburetor. A subsection of this section is formed in the control drum. The control drum controls the free flow cross section of the intake channel. A fuel opening is connected to a fuel chamber via an unbranched fuel channel which opens into the subsection of the intake channel. A simple configuration of the carburetor is achieved by the carburetor including an electrically actuated valve which controls the flow of fuel through the fuel channel. For a method for operating an internal combustion engine with a carburetor, a temperature (T) is determined before or during the starting of the engine and that the flow of fuel through the fuel channel during the starting of the engine is controlled in dependence upon the temperature (T).