Toro Groundsmaster 328-D, Service Manual

Page: 69 / 402

Control Rack Smoke Set and Ungleich Device
(Fig. 42, 43, 44)
The injection pump on the is equipped with a mecha-
nism that allows for over injection of fuel during starting,
and thereafter limits the amount of fuel delivered during
operation to reduce excessive exhaust smoke. These
devices, the smoke set plate and Ungleich set plate, are
located on the side of the injection pump and operate
by limiting the travel of the control rack.
The Ungleich device requires that the engine be OFF,
either with the key switch or emergency stop lever, in
order for the control rack to travel completely to the left
(over-injection). Once started, the action of the governor
causes the control rack to move to the right (less fuel)
until the corner of the smoke set plate engages the
shoulder of the Ungleich set plate. The amount of control
rack movement is now restricted by the locations of the
smoke set plate and the Ungleich set plate.
During extreme loading the control rack will overcome
the tension on the smoke set spring and slightly in-
crease the amount of fuel delivered to the cylinders. This
fuel increase is determined by the Ungleich set plate
and is referred to as Ungleich Effect “L” (length).
Figure 42
Figure 43
Figure 44
Groundsmaster
®
300 Series Page 4 - 39 Fuel System Service