It was my thought that the hunting, was a symptom of the governor being maladjusted, or not working correctly. I could see that the governor was controlling the throttle. I've worked on small engines for a long time, as a shade tree mechanic, but have not messed with governors much. So much of the time, clean the fuel lines and carb, and you're back in business.
First of all, messing with the governor and adjusting its static adjustment is one of the LAST things you ever do to one of these small engines if it's having a running problem, surging or hunting.
Pretty much all of these surging issues are not the governor but rather the carburetor is slightly lean
The best way to test for this on a machine that is running is to take a shop cloth or a microfiber towel and fold it into force and then hold it slightly over the intake underneath the air filter to see if it will smooth out and stop surging.
If it does, and it usually will, this confirms that it is running too lean.
Then it's a matter of cleaning out the carburetor but of course far too many people out there will then go buy a new carburetor or order one from Amazon or whatever which is also a waste of time and money.
It either needs the main jet cleared out a little bit more like it should have been from the factory or if it has a secondary idle/pilot jet, which is often the case, it needs that one cleaned out because it is often plugged solid and that will cause the surging.
Typically when there is a governor problem the engine runs smoothly but it simply won't maintain its RPMs when you put a load on it.
Sometimes it's a little more complicated than this simplistic explanation but there is just a certain sound and a certain way they run and typically they are very slow to recover up to their full speed if you hold the throttle closed to slow the idle way down to an idle speed.
This is usually the symptoms of a governor that needs adjusted but the fact is out of 500 Small engines you come across, probably not even one of them needs the governor adjusted.
It simply doesn't get out of adjustment and the only thing that needs to be done is to bend whatever Tang to adjust the spring to pull a little harder against the governor or softer to adjust the RPMs.
The actual adjustment hardly ever needs to be touched.
You can look up the procedure for a static governor adjustment but it will be hard to find an actual written tutorial with a picture or two because you'll all you'll find will be stupid YouTube videos.
Videos that take far longer to get through and get to the actual meat of the situation that you want and videos that are about 80% either completely wrong, or doing things the hard way.
Very much upsets me what the internet has become for a repair reference resource.
It is far worse than it used to be.
