A. Some makes of governors are provided with regulating screws at the top; by turning the hand nut in one direction you lengthen the valve stem and reduce the steam opening in the governor valve, which reduces the speed.
To increase the speed of the engine the handle nut is turned the opposite direction, which shortens the stem and increases the opening in governor valve, allowing more steam to enter the cylinder and the speed is proportionately increased.
The [Gardner Governors] are provided with a hand screw at the side for regulating the speed, as will be seen by examining the accompanying cut. It also has a Sawyer’s Lever for opening the valve to its full extent, and a belt tightener.
Q. Will the handle nut stay in position after once being set to a certain speed?
A. Not unless the check nut directly over the handle nut is screwed down tight to prevent the stem from changing its position.
Q. Is a governor liable to cause trouble and fail to govern the engine properly?
A. All governors are more or less delicate in construction and must be kept clean and well oiled, the belt must not be allowed to slip, nor must it be so tight as to cause the governor to work hard. The small stuffing box that packs the valve stem should never be screwed down steam tight, as it causes too much friction on the stem and prevents the balls from operating it, and the engine will run unsteadily and spasmodically. Always allow the stuffing box to leak a little, then you know it is not too tight.
First class governors may sometimes be condemned for not regulating the engine to a uniform speed, when a good cleaning, oiling or loosening of the valve stem stuffing box nut would allow them to work perfectly.