You have change the carburator and maybe the small lever at the end shaft have to be returning 1\2 turn or change the carburator again

I just check the pony motor parts number 8f4681 and this poney came from power unit and on w21 serie 8w1 up

I figured out the adjustment procedure. The two guiding principles are that the throttle on the carburetor has to be able to hit the idle stop and it has to be able to hit the maximum open stop. So you fit the linkage to the governor and the carburetor and and then simply adjust the length of the rod so that the carburetor can hit the idle stop and with the governor at full open the throttle on the carburetor should also be full open and you can probably even adjust it so that there's a little bit of extra free space on both ends of the travel. I think that's that's all that needs to be done to adjust that rod now that I've done it once. 

I got the thing to fire up today and it sounded like a champ and the throttle was moving under the motivation of the governor quite easily and freely and apparently correctly.

All that remains now is to set the high idle RPMs and the idle RPMs.

So thanks for all those at pitched in and gave me ideas on how to deal with this.