What is the matter with my govenor?

I'd say something has happened or someone has been messing with the governor spring and who knows what else.

About the only way out is to get another spring (same part number) from
another governor or exchange a complete governor assembly. Calibration information for the springs has never been available as far as I know.

Here is a picture for comparison:

Hi Team,
seeing your machine ran fine previously it is not likely to be a problem with the position of the Gov. Spring on the base part. It is normal for the spring to not be screwed fully up onto the base---the Factory adjusts the spring position and locks it in place from what I recall when working on this style of Gov. at The Dealer.

I feel you have slack/lost motion in the linkage from the handle at the air cleaner down to the the actual Gov. control shaft.
I have found you need to give the operators handle a good shove to get past the Shut Off detent to stop the engine and again a good pull to get back past the detent to the Run position. There is a fair amount of free travel between the Shut off /Low Idle detent and the Full shut off position and back again to get past the detent to the Low Idle---Run position.
Maybe operate the Gov via the small handle at the Gov. itself and see what happens.
Your pix appear to show the Gov. and inner workings in the Shutoff positon.

Hope this helps.
Cheers,
Eddie B.

Thats a different spring in the second photo. They did use different springs on the later tractors with increased hp. Notice the length of the bolt compared to the other one.

The governor shown is a pre-engine balancer model about 1951.

Is my face red. The problem was my ignorance. It turns out that the throttle has a LOT of movement beyond the shut-off detent. This confused me into thinking the throttle was at fast idle when it was only advanced to the back side of the stop detent. I had not given it enough oomph to get it past the idle stop to give it some fuel. It starts and runs just fine again. I wish you could hear it. Thanks a lot for your attention.