Small Engines (Lawn Mowers, etc.): 4HP Craftsman Mower --- Low RPM, throttle shaft, time governor

Question
Hello, Eric.  

4HP Craftsman engine model 143.324022 (made in early 80's).  Starts fine, but top rpm almost too low to cut grass without bogging.  Revs up fantastic if I reach down to the carb and push the throttle shaft lever manually, but drops back to low rpm as soon as I release.  Governor spring, governor spring link, and governor-to-throttle link appear OK, but I'm no expert.  Any ideas?  Thanks for your time.

Answer
Governor springs can stretch and become weak over time.

Look at the throttle control plate, the plate that sits on top of the carburetor, to see if there are screw adjustments. The screws have springs on them and are located under the control plate.

Let me know what you find.
Eric