Should both upper and lower carbs have same venturi. Serial #4578141. If so, this motor's upper carb has a different one than lower. Where can I find a replacement. Pulled carbs for cleaning and the venturi from upper fell out because it had only one ear tab so there is no way to keep it place. Supposedly no longer available as a new part from supplier. How would this affect motor performance if not installed? Any help appreciated.
