Hello,

If you are reffering to the stop lever oscilatiing - then the fault was found to be an improperly mounted / installed shutoff valve. The barrel shaped tange on the arm of the shutoff valve must be seated properly not on top of the arm ( which causes the oscilation symptom ) and NOT underneath ( this will cause runaway - and engine will blow if not arrested) but rather in between there is an intended slot.
Hope this helps.
Happy Holidays to All