21:14. Control system of the electromagnetic valve of the carburetor

Scheme of connections of a control system of the electromagnetic valve of the carburetor

1 – ignition switch;
2 – ignition relay;
3 – ignition coil;

4 – control unit
; 5 – electromagnetic valve;
6 – trailer switch of the carburetor.

The control unit of the electromagnetic valve of the carburetor switches-off the valve (interrupts fuel supply) at increase in frequency of rotation of a bent shaft up to 2100 min.-1 and includes at decrease in frequency of rotation up to 1900 min. –1 if the trailer switch of the carburetor is closed on weight (the pedal of "gas" is released). At the pressed pedal of "gas" (the opened switch) the valve is switched on irrespective of the speed of a bent shaft (fuel moves). Food on the control unit moves only at the included ignition therefore at switching off of ignition also the valve is at the same time switched-off (irrespective of position of the trailer switch of the carburetor) that it prevents operation of the engine with spontaneous ignition (the electromagnetic valve is normally closed).

For check of operation of the control unit we connect the voltmeter parallel to a winding of the electromagnetic valve (operation of the valve can be determined also by its knock, without connection of the voltmeter). We disconnect a wire from the trailer switch of the carburetor and we close it on "weight". We launch the engine and, gradually increasing the frequency of rotation of a bent shaft, we monitor indications of the voltmeter. After launch of the engine the voltmeter has to show not less than 10 V (the valve is open), and at turns about 2100 min. –1 tension has to decrease sharply to size no more than 0,5 V (the valve – is closed). After that slowly we lower engine turns, about 1900 min. –1 tension has to increase in steps to former size (the valve – to open). We establish turns within 2200–2300 min. –1 (the valve is closed) and we disconnect a wire of the trailer switch of the carburetor from "weight" – the valve has to open.

Removal of the electromagnetic valve see Removal and check of the electromagnetic valve.