Engine Braking

In downhill operation the engine is driven by the vehicle; engine speed tends to increase. The weights swing outward and the sleeve pushes against the starting and tensioning levers, which in turn move the control collar toward less fuel delivery. This continues until the smaller delivery corresponds to the new load condition, at the extreme falling to zero. If the engine is completely unloaded, maximum idle speed is reached.
The processes described here for the variable-speed governor are valid for all positions of the speed-control lever when engine speed or load changes sufficiently that the control collar moves to either its full-load or stop position.