Steering Control Lever Response Adjustment; Tracking Adjustment; Pto Drive Pulley Alignment - Exmark NAVIGATOR NV640KC Operator's Manual

Set forward stop bolt:
1. Remove seat deck (with seat attached) to obtain
a clear view of the steering control shaft to
complete this adjustment.
2. Push the speed control lever forward to full
forward speed position.
3. If either steering control lever surface does not
contact the stop bar at the full forward speed
position, adjust the stop bolt until contact occurs
(see Figure 19). Once contact occurs, turn the
stop bolt one more full turn to prevent bottoming
of the hydraulic pump internal stops.
Figure 19
1. Speed control Lever
forward stop bolt
Steering Control Lever
Response Adjustment
1. Stop engine, wait for all moving parts to stop and
remove key. Engage parking brake.
2. Move the speed control lever to the full forward
position.
3. Lift the seat and locate the pump control springs.
To increase responsiveness, increase spring
tension by hooking the rear spring anchor directly
to the anchor bolt. To decrease responsiveness,
hook the rear spring anchor to the anchor tab.
Note: Be sure both springs maintain the same
adjustment.
2. Contact must be
maintained between
these components at full
forward speed condition
1. To increase steering responsiveness hook
pump control sprints directly on anchor bolt.
To decrease steering responsiveness hook pump control
springs on anchor tabs as shown.

Tracking Adjustment

See Motion Control Linkage Adjustment section

PTO Drive Pulley Alignment

PTO drive pulley alignment is necessary for any of
the following conditions:
• The blower has been removed or replaced.
• The engine mounting bolts have been loosened or
the engine has been moved or replaced.
• The jackshaft mounting bolts have been loosened
or the jackshaft has been moved or replaced.
1. Stop engine, wait for all moving parts to stop, and
remove key. Engage parking brake.
2. Move the speed control lever to the neutral
position.
3. Disengage the PTO lever.
4. Remove fuel tank mounting nuts and swing out
fuel tank.
5. Verify that the blower is installed and secured
tightly.
6. Loosen the four engine mounting bolts.
7. Unhook the pump belt tension spring.
8. Loosen the four jackshaft mounting bolts.
9. Measuring from the blower pulley as a baseline,
move the engine and jackshaft until the rear
surface of all three pulleys are aligned within 1/32
35
Maintenance
Figure 20