Hi Steve,
I don’t know if you have already done this but, mount the movement on a movement stand for bench test. That way you can see exactly what the movement is doing. Do this with good lighting . Also try putting the hands on so you can advance the time and watch those levers and cams like William suggested. You could have a bent arbor or a marred tooth on one of your gears. Let us know what you find. I wish you well 
Jim