governor update

[SDE]

I found my manual. The spring that puts tension on the speed change lever (9) is 1.9 inches long. That is too short to keep tension on the speed change lever. I slipped a 5/6 inch nut on the rod an now there isn't any slop on the rod. I shortened the clevis (11) as much as I could on the throttle rod (10).

I adjusted the idle speed and it idles more smoothly now. At about half throttle I held the throttle rod (10) and the rpms stayed constant. It still hunts/surges a little at WOT, but I don't think it warrants digging deeper to fix.
TY
SDE

 

[used red MN]

Just for the sake of discussion why not hold the governor linkage to the carb still at wide open throttle to see if it runs steady then. If I was working on a C with the issue you are describing that is what I would do. This way I would know if the engine held steady with the throttle plate held at one position that adjusting the carb more would not be the answer to fixing the problem. In general slight hunting at wide open throttle can usually be taken care of by adjustment of the main jet. However, the recommended slightly rich mixture will tend to cause the engine to lope slightly. This diagnostic tool is a bit more difficult to use on the H and M and their variants because the linkage between the governor and carb is all enclosed. They can be accessed fairly easily by unbolting the slanted cover with the vent tube on it above the governor. I also believe the enclosed linkage applies to the earlier Regular, F12, F20 etc. not real sure on that, have not been around those models. I will attach a link to your previous post on this subject so the topic has some background.
Previous post on subject.