4.1 Intake air temperature control system: when the engine is cold, the choke is open and hot air from the exhaust manifold enters the carburetor
1. Vacuum diaphragm; 2. Air intake pipe; 3. Air filter; 4. Temperature sensor; 5. Vacuum from the intake manifold; 6. Exhaust manifold; 7. Heat shield; 8. Air outlet; 9. Hot air; 10. Air damper; 11. Cold air
1. The system reduces the content of carbon dioxide and hydrocarbons in the exhaust gases, reduces engine warm-up time and reduces carburetor icing. The temperature of the incoming air is controlled by an air damper located in the intake manifold, regulating whether the air comes from the atmosphere, from the exhaust manifold, or from both sources (4.1).
2. The damper position is controlled by a vacuum diaphragm. A temperature sensor in the air filter housing monitors the vacuum at the diaphragm.