On my to-35 if you pull the choke rod and close off inlet air to the carb,
the motor slows and the engine will die if choke is not released.
I would assume your carb is stopped up an needs a good soaking in carb cleaner and a rebuild.
After motor warm-up, my tractor will idle at 400 rpm's. Also, the motor should take the fuel without hesitation under load.
You may need a full tuneup, I normally get tuneup parts at napa including new spark plug wires.
Your air filter tower may be stopped up with dirt, that will require it be taken off, soaked in cleaner and washed out.