I have an old 9.2 I am puttering with. I can get it to start/run when throttle is wide open. There are 2 butterflies inside the carburetor 1 attached to the choke knob and the second activated by the throttle linkage. the motor will start when the second butterfly is open. There seems to be a timing mark below the flywheel where the roller that opens the second butterfly is located. What does that mark indicate. There is no kill button that i'm able to find just stop on the throttle, what shuts this motor down? I have pictures if that will help.