First, there is something odd with your choke rod connection to the choke. If you look at Figure 54 you will see there should only be one hole in the choke for the choke rod. You either have two holes, or the rod is not in a hole.

Second, the engine has an air vane governor, not a centrifugal one. The vertical piece of sheet metal with the row of holes is the air vane. Air pressure on the vane, from the cooling fan, pushes the vane in the direction to close the throttle. Pressure from the governor spring (painted orange on your engine) tries to open the throttle, so a balance is achieved between the two forces on the vane.

You cannot see, when the engine is stopped, what speed the governor is set for. Moving the speed control lever pulls on the governor spring. At first, when the engine is not running, the vane just moves closer to the flywheel fan until it runs out of movement. When the engine is running however, the vane is affected by air pressure from the fan and resists going closer to it.
If you look the upper illustration in Figure 56, below, you will see that your throttle butterfly link goes in the uppermost hole in the governor vane, and the governor spring goes in the second hole. The lower holes are for other engines that use the same vane. Note that the lower illustration in Figure 56 shows the later generation of air vane, which was horizontal with a proper pivot.
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