The rotating knob coming right off the carb is the choke, and that's fine as is. The lever on the blower housing goes to the governor, which in turn goes to the butterfly. The lever assembly doesn't move freely since it's meant to set a constant speed. That will have to be addressed along with some kind of barrel adjuster and pinch bolt added for the cable. Wish I could help more, but the only Tecs I've had were on tillers so I haven't had to modify one for a cable.
Landuse pointed out lowering your idle, and that sounds like a good place to start. In the pics you posted the motor is throttled up, so make sure you don't have it engaging the clutch because of that. The idle adjustment is on the top of the carb, it will be the screw with the spring on it.