Exmark Viking Hydro Operator's Manual page 40

4. The spring that keeps tension on the knob should normally not need
adjustment. However, if adjustment is needed, adjust to where length
of spring is about 1" (2.5 cm) between the washers. Adjust spring
length by turning nut at front of spring.
d) Drive Lever Linkage Adjustment
1. With rear of machine still on jack stands and engine running at full
throttle, disengage the park brake and move the speed control lever to
the midway position. Move the respective drive lever upward until it
reaches the neutral position and engage neutral lock latches. See
Figure 21. If the tire rotates in either direction, the length of the drive
lever link will need to be adjusted.
2. Adjust the linkage length by loosening the jam nuts at both ends of
the linkage and rotating the linkage in the ball joints. Lengthen the
linkage if the tire is turning in reverse and shorten the linkage if the
tire is creeping forward. Tighten the jam nuts at both ends. Release
and re-engage the neutral lock latch checking that the tire stops.
Continue this process until the tire is at a dead stop.
DRIVE LEVER AND LATCH IN NEUTRAL POSITION
3. Make this adjustment for both sides.
e) Tracking Adjustment
1. Stop engine and wait for all moving parts to stop. Raise the rear of
the machine, remove jack stands and carefully lower the machine to
the ground. (Check the drive tire pressure and tire circumference.
See 5.1.11.)
2. Run the unit and observe the tracking on a level, smooth, hard
surface such as concrete or asphalt.
3. If the unit tracks to one side or the other, turn the quick track knob.
Turn the knob right to "steer" right; turn the knob left to "steer" left.
5.2.10 Hydro Pump Spring Tension Setting:
a) For medium or heavy duty drive conditions such as operation with a sulky
on steep slopes, a higher spring force may be required on the hydro
pump control arms to prevent the drive system from stalling.
b) For a heavier drive setting, relocate the spring anchor links to either the
"medium" or "heavy duty" positions as shown in Figure 22. The spring
anchor links are attached to the upper rear corner of the hydro drive
shields on the left and right hand sides of the machine.
Note: In the "medium" or "heavy duty" positions, the drive lever forces
at the upper handle will also be increased.
FIGURE 21
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