It would be more sensible to pull the safety lanyard off rather choke it to death. There's no objection to doing that but I am pretty sure you can still press the stop button with the lanyard in place.push out the chocke button will kill the engin
I have the E/rude version, and the lanyard/clip is an emergency feature. In normal use you can simply push on the red knob at the end of the tiller to stop the motor...as Vic suggests.That is the stop switch. Can you not press the centre of it to stop the engine with the lanyard still in position ?
(Also, if its like earlier models, the knob it is mounted in turns to adjust the idle speed)