Scheme of heating the air entering the carburetor:
A - cold air supply duct; B - warm air supply duct; 1 — damper; 2 - heat sensitive element; 3 - thermostat with double bimetallic spring; 3a - check valve with brass branch pipe (approximate opening temperature + 18°C); 3b - ventilation hole with a diameter of 0.51-0.05 mm; 3c - ball valve (approximate closing temperature below +18°C, approximate opening temperature above +23°C); 3d — throttle hole with a diameter of 1±0.1 mm (plastic pipe). The check valve must compensate for any change in pressure no later than 2-3 minutes.