Abstract: A method for controlling the operation of a spark ignition internal combustion engine is described. The engine includes: a combustion chamber, an intake duct for placing the combustion chamber in communication with the external, a throttle valve arranged inside the intake duct, a carburetor for introducing fuel into the intake duct to form an air/fuel mixture to be intaken into the combustion chamber, and a spark plug arranged inside the combustion chamber to generate a spark for igniting the combustion of the air/fuel mixture. The method includes: monitoring the opening degree of the throttle valve; monitoring the speed of the engine, preventing the spark plug from generating the spark, if the opening degree of the throttle valve drops below a first opening degree threshold value and the speed of the engine is greater than a first engine speed threshold value.

Abstract: A control system for carburation of an internal combustion engine in use conditions comprising following activities: starting the engine with a value of ? equals ?0=?T; constructing a curve ci(?) of the ionization current ? as a function of the angular position a of the crank shaft; selecting, on this curve ci(?), a number of points at intervals ?? of the rotation angle a; calculating value z, equal to integral from 0 to 360° of the curve ci(?), is done by summing products ??×ci for all preselected points; interrupting supply of fuel for some cycles in order to externally modify factor ?0 and take it to value ?1; for value ?1 constructing curve ci(?) and calculating value z1; calculating difference ?z=z1?z0, and if the difference is >?zref in absolute value, intervening on carburation by increasing the quantity of fuel injected in a case of a positive difference (lean mixture) and by reducing the quantity of fuel injected in a case of a negative difference (rich mixture).

Abstract: A method for controlling the operation of a spark ignition internal combustion engine is described. The engine includes: a combustion chamber, an intake duct for placing the combustion chamber in communication with the external, a throttle valve arranged inside the intake duct, a carburetor for introducing fuel into the intake duct to form an air/fuel mixture to be intaken into the combustion chamber, and a spark plug arranged inside the combustion chamber to generate a spark for igniting the combustion of the air/fuel mixture. The method includes: monitoring the opening degree of the throttle valve; monitoring the speed of the engine, preventing the spark plug from generating the spark, if the opening degree of the throttle valve drops below a first opening degree threshold value and the speed of the engine is greater than a first engine speed threshold value.

Abstract: A control system for carburation of an internal combustion engine in use conditions comprising following activities: starting the engine with a value of ? equals ?0=?T; constructing a curve ci(?) of the ionization current ? as a function of the angular position a of the crank shaft; selecting, on this curve ci(?), a number of points at intervals ?? of the rotation angle a; calculating value z, equal to integral from 0 to 360° of the curve ci(?), is done by summing products ??×ci for all preselected points; interrupting supply of fuel for some cycles in order to externally modify factor ?0 and take it to value ?1; for value ?1 constructing curve ci(?) and calculating value z1; calculating difference ?z=z1?z0, and if the difference is >?zref in absolute value, intervening on carburation by increasing the quantity of fuel injected in a case of a positive difference (lean mixture) and by reducing the quantity of fuel injected in a case of a negative difference (rich mixture).