Engine Tune-Up
increases, as a result of the increased fuel, until the
The centrifugal force of the revolving output shaft
output shaft governor weight force is sufficient to
governor flyweights is converted into linear motion
balance the increased spring tension. The weights then
which is transmitted through a riser, thrust bearing,
move against the spring and reduce the injector rack
operating fork, and rocker shaft to an external speed
fuel setting to an amount sufficient to maintain the
adjusting spring. The speed of the torque converter
higher engine speed setting.
output shaft is governed by the tension of the speed
adjusting spring. This spring tension is established by
If the operator moves the speed adjusting shaft lever
the operator when he moves the output shaft governor
to a decreased speed position, the tension on the speed
speed adjusting lever to the desired speed setting.
a d j u s t i n g spring will decrease and the governor
weights will overcome the spring tension and move the
The engine governor operating lever is positioned by
rocker shaft lever to a decreased fuel position. The
the operator to limit the maximum fuel input to the
engine speed will be reduced until the force of the
engine. For most purposes, such as drag line and
output shaft governor weights equals the tension of the
shovel operation, the lever is advanced to its maximum
speed adjusting spring. The engine will then operate at
position to permit the output shaft governor to obtain
the desired reduced engine speed.
full power from the engine. The lever may be used as
an overrule lever when performing such jobs as laying
When a load is applied to the unit, the output shaft
of structural steel. A spring is used to return the lever
slows down and the force exerted by the governor
to the idle position. Travel of the governor operating
flyweights is reduced, allowing the spring to move the
lever is limited by a stop (bolt).
rocker shaft lever to an increased fuel position to
provide sufficient power to equal the new load.
The engine governor throttle control lever is pinned to
the throttle shaft. The engine governor operating lever
When the load on the unit is removed, the output
is mounted below the throttle control lever and rides
shaft speed will increase and the force exerted by the
on the throttle shaft boss on the governor cover. The
governor flyweights will increase, overcoming the
output shaft governor lever is mounted above the
spring tension and moving the rocker shaft lever to a
throttle control lever and is retained on the shaft by a
decreased fuel position to reduce the power to match
snap ring. A stop pin, pressed into the throttle control
the reduced load.
lever, t r a n s m i t s m o v e m e n t o f t h e o u t p u t s h a f t
governor lever and/or engine governor operating lever
through the throttle control lever to the injector racks.
Tune- Up
The torsion spring, used to retain the throttle control
lever stop pin against the output shaft governor lever,
Adjust the exhaust valve clearance, time the fuel
yields to permit the governor operating lever to move
injectors and adjust t h e engine and output shaft
the throttle control lever toward the idle position,
governors as follows:
regardless of the position of the output shaft governor
lever. A slot in the underside of the governor cover
1. Adjust the exhaust valve clearance and time the
hub limits the travel of the throttle control lever in
injectors.
both its maximum and minimum speed positions.
2. Disconnect the output shaft governor rod and the
Movement of the output shaft governor speed
linkage to the engine governor operating lever. Then
adjusting lever i s limited by the maximum and
adjust the engine governor as outlined under Limiting
minimum speed adjusting bolts.
Speed Mechanical Governor and Injector Rack Control
Adjustment.
The engine shutdown lever is connected through a
shaft to another lever, under the governor cover, which
NOTE: Set the No-Load engine speed to that
bears against the pin in the differential lever. To stop
specified on the engine option plate. The No-
the engine, the shutdown lever is used to move the
Load speed varies with the converter used and
differential lever to the no-fuel position.
the maximum output shaft speed setting.
3. Reconnect the linkage to the governor operating
Operation
lever and check the total travel of the operating lever.
The lever should move the stop (bolt) in one direction
When the output shaft governor speed adjusting lever
and the governor lever return spring should move the
is advanced. the tension on the speed adjusting spring
lever, in the other direction. until the throttle control
is increased. The force resulting from the increased
lever reaches the end of its travel.
spring tension is transmitted through the rocker shaft
lever and control linkage to the throttle control lever
4. Move the governor operating lever to the maximum
which advances the injector racks. Engine speed
speed position (against the stop bolt).
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