How Does an older Carb without a Choke Pull Off Do It?

Murray said

The purpose of the thermostatic choke spring is to close the choke butterfly when cold. Spring tension on the butterfly is "light". When the motor starts, airflow opens the butterfly slightly. This is not as precise an arrangement as a carb with a pull-off.

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And when the choke thermostat coil heats up the choke butterfly comes open. There is no vacuum pull off so the choke coil in the intake and the air flowing past the choke butterfly open the choke. Disagree with me if you want but that's the way it works! Some of the Holley's have a small vacuum chamber that cracks the butterfly open as soon as the engine fires. I don't see that this carb does.