Can you compare to another tractor to see if you are missing some parts or something not connected? there is a linkage needed to the carb and a heavy spring, the cable in the spiral case is the throttle and to test is see if it moves on the end attached to the carb if you move the lever by the dash. Mine leaked oil from the shaft going into the governor cup. i had to take it apart, not too easy to do, its the round cup in front of the motor. Inside it there are precision roller bearing and fly weights, the seal and some shims, there needs to be oil going in there from the motor. the linkage from the governor back to the carb should move when the motor slows and the fly weights come in because of their slower rotation
I'd find a tractor that works and have a look at it
good luck