Air Cleaner - Thermostatic: Operation

When ambient air temperature is less than 50°F (10°C), carburetor intake air flows through shroud, into flexible connector, through vacuum diaphragm and into carburetor.

When temperature rises to operating temperature, vacuum diaphragm shuts off air coming from shroud, and allows fresh air to enter carburetor. When temperature is between minimum and maximum, air will flow through both circuits.