Air Cleaner - Thermostatic: Description
On models equipped with carburetor, a system for pre-heating air entering carburetor is used. This system is part of the air cleaner and maintains air temperature at a point where carburetor can be calibrated at leaner setting to reduce hydrocarbon emissions and improve driveability during warm-up.
These systems are vacuum-operated and consist of heat shroud on exhaust manifold, hot air duct, thermal sensor switch, vacuum motor, air valve assembly and reverse delay valve.