3-10. VARIABLE SPEED MECHANICAL GOVERNOR - MAINTENANCE INSTRUCTIONS (Cont).
The centrifugal force of the governor weights is opposed by the variable speed spring. Load
changes or movement of the speed control lever create an unbalanced force between the revolving governor
weights and tension on the variable speed spring. When the two forces are equal, the engine speed stabilizes
for a setting of the speed control lever.
Fuel rods connected to the injector control tube levers and the control link operating lever
assembly are operated by the differential lever, through the operating lever connecting link. This allows the
governor to change the fuel settings of the injector rack control levers.
The engine idle speed is determined by the centrifugal force required to balance out the
tension on the variable speed spring in the low speed range.
To adjust the engine idle speed, change the tension on the variable speed spring by adjusting
the idle speed screws. Adjustment of the maximum no-load speed is done by varying the tension on the
variable speed spring by installing or removing stops and shims.
The governor is lubricated by a spray of lubricating oil from the blower end plate. The governor
weights distribute this oil to all parts of the governor assembly requiring lubrication. Oil returning from the
governor goes through passages in the blower end plate and cylinder block to the engine oil pan.