fatone, could you let us know when you have put the governor together properly and tried it out please? You just need to do three things.

1. Remove the piece of wire that runs from the bottom of the governor arm to the control protector front attachment screw. It isn't a Honda part and shouldn't be there - all it does is lock the throttle in the closed position. Tighten the front attachment screw after you remove the wire from underneath its head.
2. Install a governor spring where it belongs: - Attach one end to the bottom of the governor arm (the hole you removed the spurious wire from in Step 1). - Attach the other end of the spring to the hole near the bottom of the control lever.

When you have done that you should find that the speed control cable stretches and relaxes the governor spring, and the throttle butterfly moves when it does so. If you are lucky that will be the only part of the mower that has been messed up, but as I said previously, be careful when you first start it, and switch if off if it does not work properly.