The 6V6070 Governor Adjusting Tool Group is needed to make fuel system adjustments on
3204, 3300 and 3406 Engines that are equipped with the New Scroll Fuel System.
the throttle of operator is connected to governor control lever, there is several positions of the lever
fuel off- low idle - high idle
to set the value of low and high idles , we use two screws, the inner component of the governor are
spring seat
spring
riser
flyweight assemble
pivot lever
rack connected to servo
rack has two movements named
fuel off - when moved towards front
fuel on - when moved towards back
setting governor lever to position low idle, mechanism pushes spring to pivot shaft and move rack to fuel on
When the engine is cranked, a large amount of fuel is injected into the combustion chamber, so at the beginning of engine running, the engine RPM is immediately high. Once the engine is running, the flyweight rotates, and begins to expand pushes the riser and spring, thus moving the rack toward the fuel off, reducing the amount of fuel injected. The flyweight and spring forces will push each other until a balanced condition occurs.
The engine RPM will drop to match this balance
The position of the rack, how much it is fuel on or fuel off, depends on the RPM and load.
Maximum movement of the rack is determined by full load screw and full torque screw whose mechanism is connected to the riser.
At the point the rack screw (green) first comes in full contact with the
torque spring, the rack is at full load point (rated). As demand
horsepower increased, with the rack at rated position, the engine
speed decreases as the engine goes into lug (full throttle with rpm less
than rated rpm). Depending upon the rigidity of the torque spring, at
some point, the governor spring causes the rack screw to begin to
depress the torque spring. As this occurs, the rack position increases
allowing more fuel to be injected per stroke. This increase in rack
position continues until the torque screw (violet) contacts the stop
bar. This is the full torque position of the rack
and the maximum fuel injected into the combustion chamber.