Abstract: The vacuum motor and link assembly used to pull-off a carburetor choke valve when an engine is started is made tamper resistant to prevent someone from changing the position at which the vacuum motor causes the choke valve to open. A cover is installed on the carburetor and shrouds the vacuum motor, link, and the portion of a choke shaft to which the link is connected thereby to prevent access to these parts.

Abstract: A carburetor for an internal combustion engine has a choke valve mounted in an air induction passage. A choke lever is attached to one end of a choke shaft on which the choke valve is mounted. An improvement comprises a tamper resistant temperature responsive mechanism for controlling opening of the choke valve as the engine warms up. The mechanism includes a housing, a choke countershaft, one end of which extends into the housing, and a cover attachable to the housing and containing a thermostatic coil. A lever is attached to the one end of the counter shaft and the lever has a tang contacted by one end of the thermostatic coil. A substantially straight, nondeformable link connects the choke countershaft and choke lever. The lever within the choke housing is adjustable to position the lever so opening of the choke valve is properly controlled and the setting of the lever cannot be tampered with once the cover is attached to the choke housing.

Abstract: A carburetor for an internal combustion engine has an air passage through which air is drawn into the engine, an unbalanced choke valve positioned in the air passage and movable between a closed position and a fully open position, a thermostatic device responsive to engine temperature for urging the choke valve closed with a force which diminishes as engine temperature increases, and a suction motor responsive to engine vacuum for urging the choke valve open with a force which increases as engine vacuum increases. The position of the choke valve at any time is determined by the net effect of the above said forces. A load is applied to the choke valve when it is closed to dampen its movement during cranking of the engine to facilitate starting. Further, the load forces the choke valve closed when it is between its closed position and a predetermined position intermediate its closed and fully open positions.

Abstract: A carburetor for an internal combustion engine is provided with auxiliary fuel means for continuously regulating the fuel air ratio from a first, cold start condition to a second, normal run condition. The auxiliary fuel means includes a vacuum operated metering system to provide the additional fuel required for starting and running the engine untile the engine reaches normal operating temperature, and a combination shut-off valve and air bleed. In the preferred embodiment, the air bleed is actuated by manifold pressure overcoming the closing force of a thermostatic coil, and is open whenever the engine starts. The air bleed increases air input to the auxiliary fuel supply, thereby reducing fuel richness after start. A temperature sensitive element such as a bimetal coil is utilized to operate the shut-off valve and completely closes the auxiliary fuel means input to the engine at some predetermined temperature.