Ok, I have been flying for many years but just got into gas engines.
I am setting up a BME 50 up on a GP Patty Wagstaff but here is my question:

Do I have to set the choke up on a servo? And if so, How do I do it (see pics)?
The degree of the arm would not work with a servo.
The first pic is with it closed and the second is open. Look at the arm. How can I get that to work or do I need it hooked up to a servo?

Thanks for your help
David