I am working on a Cub mower which has a Micki carb 698620 and I took it apart and cleaned iit but it still serges. If you hold the throttle with your finger it runs better. I have another enging with that same carburetor on it which does the same. They are a bad design carburetor that briggs used.
Not a bad design, just needs a bit more patience and understanding on how carbs work. They get a bad rap because people don’t have the patience or want to stick the time into properly cleaning and rebuilding. With a little searching there are some good videos on how to clean and rebuild them. Takes about twice as long as a Walbro or Tecumseh carb. Search Nikki carb rebuilding.
