I'll change the z bend on the throttle, just got in from work. I haven't tried anything yet but will start there, and try the other suggestions if this doesn't solve the jitters. I range checked my other models and they have metal clevises on the throttle and work fine. I think the Giles actually has a z bend on throttle just like this one. I hope it is as simple as the metal to metal but I think I got bigger troubles. Get back to you soon as I can