Checking the device for heating the air entering the carburetor
The air supply to the carburetor is regulated depending on the load and engine temperature. On a cold engine, under the influence of a heat-sensitive element 2, damper 1 must completely close the cold air supply channel «A» (see picture). On a running or hot engine, the warm air supply must be closed «IN».
If this does not happen, the thermostat 3 with a double bimetallic spring or the heat-sensitive element 2 and its drive are faulty.
Electropneumatic ignition timing control valve
Electropneumatic valve contacts open:
- with the ignition off;
- idling at a coolant temperature below +17°C;
- with the engine running with the throttle in the partial load position;
- with the ignition on, at a coolant temperature above about +20°C;
- idling at a coolant temperature above about +20°C.