Abstract: A carburetor comprises an intake passage for supplying air and fuel, a venturi located in the intake passage, a nozzle opened in the venturi, a float member communicated with a fuel supply source and with the nozzle, an air vent for communicating the space above the liquid surface in the float chamber with the intake passage upstream of the venturi, and two communication conduits each of which has one end opened above the liquid surface in the float chamber and the other end opened at a suitable position in the intake passage in such a manner that a pressure difference is caused between the two communication conduits. One end of the first communication means is provided close to a fuel opening connected to the fuel supply source in the float chamber and the other end thereof receives higher pressure. One end of the second communication means is provided far from the fuel opening and the other end thereof receives lower pressure.

Abstract: An apparatus for measuring the spark gap between the electrodes of the spark plug for automobile internal-combustion engines, comprising a probe adapted to detect a secondary voltage and having a potential divider circuit therein for supplying a low-voltage signal, and a plurality of electrical circuits for processing the signal and indicating the spark gap as detected for each cylinder on display means.

Abstract: In an engine automatic control system for a vehicle for automatically connecting an electric source in the form of a battery with an engine starter and an ignition circuit in response to disengaging operation of a clutch device of the vehicle, for maintaining the ignition circuit conductive while the vehicle runs, and for automatically making the ignition circuit non-conductive when the vehicle is arrested, the engine control system comprises a setting circuit interposed between an ignition switch and the ignition circuit for selectively setting the engine control system to its operative condition and a cancelling circuit coupled with the setting circuit for automatically cancelling the operative condition of the engine control system when the stored voltage of the battery is lowered to or below a predetermined low value.

Abstract: An apparatus for detecting and indicating the pressure under which the air-fuel mixture is compressed in an internal-combustion engine for automobile vehicles, and more particularly an apparatus of the type which comprises probe means adapted to detect a compression pressure exerted during the compression stroke in the combustion chamber, and a plurality of electric circuits for processing signals from the probe means and indicating on display means the compression pressure as detected.

Abstract: In an engine automatic control system for a vehicle for automatically connecting an electric source with an engine starter and an ignition circuit in response to disengaging operation of a clutch device of the vehicle, for maintaining the ignition circuit conductive while the vehicle runs, and for automatically making the ignition circuit non-conductive when the vehicle is arrested, the engine control system comprises a setting circuit interposed between an ignition switch and the ignition circuit for selectively setting the engine control system to its operative condition and a cancelling switch coupled with the setting circuit for automatically cancelling the operative condition of the engine control system when an operator leaves the vehicle.