Automatic Air Temperature Control Valve

When ambient temperature is below approximately 25-30°F (-4 to -1°C), thermo sensor will position air control valve in up (heat on) position. This allows only heated air, which is gathered from around the exhaust manifold, to enter the carburetor.

As ambient temperature increases, air control valve moves downward, to allow some cooler outside air in. This modulating operation keeps air temperature in air cleaner constant. Once ambient temperature is above 90-100°F (32-38°C), air control valve will be fully down; only cool, outside air will be allowed into the carburetor.