Z force – Cub Cadet Z-Force Series User Manual
Page 32
Z Force
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14.6. Set the governed idle to 1,550 R.P.M. using the
screw at the lower right hand corner of the con-
trol bracket. See Figure 14.6.
14.7. With the governed idle and idle throttle stop
adjusted, the engine should maintain a 1,550
R.P. M. idle, but should not fall below 1,000
R.P.M. unless the engine is over-loaded.
14.8. Top no-load speed should be adjusted to within
the range of 3,600 to 3,650 R.P.M. This is done
by slightly bending the arm on the control
bracket that pulls on the governor spring.
NOTE: If high speed governor response is slug-
gish, check for interference between the gover-
nor rod and the governor spring.
NOTE: If high speed performance is weak, con-
firm that the choke is not closing prematurely.
14.9. Adjust the choke using the screw on the control
14.10.With the engine turned-off, insert a 1/4” pin in the
round hole when the throttle is set for top no-
load speed. This will lock the linkage in that
position.
14.11. Using a phillips head screwdriver inserted from
behind the left corner of the control bracket, set
the choke adjustment screw to leave a .199” gap
between the tip of the screw and the point where
it contacts the arm that actuates the choke rod.
14.12.After all carburetion adjustments are made, run
the engine to double check the idle speed, throt-
tle stop, top no-load speed, and unimpeded link-
age movement.
NOTE: Because the Z-Force engine is not
equipped with a fuel shut-off solenoid, after-
boom may occur if it is turned-off at idle speed.
This will cause no harm, but customers may find
it objectionable. To avoid after-boom, the engine
should be throttled-up slightly at the moment of
shut-down. The opening of the throttle plate will
reduce the vacuum level in the intake manifold,
preventing the ingestion of a rich fuel air mixture
from the idle jet on over-run. After the ignition
(spark) is turned-off, the inertia of the engine will
pump unburned fuel and air into the hot muffler.
The presence of this mixture in the hot muffler is
the source of after-boom.
Figure 14.6
Governed idle
adjustment screw
Figure 14.8
Governor
spring
Governor rod
(to throttle on
carburetor)
Governor arm
Adjust here
Figure 14.9
Insert 1/4” pin
Choke
actuator arm
.100” gap
(2.7mm)
Adjustment
screw