10
Changing the Speed/Sensitivity
Adjustment
The controls are initially set with the Speed/
Sensitivity
Adjustment in the
faster, more
sensitive position. If
an operator is not
completely familiar
with the mower
operation the
operator may desire
to decrease
the ground speed. The slower setting has a
corresponding decrease in the sensitivity of the
controls. In other words, a given amount of
movement of the control levers will cause about
a 25-30% change in the ground speed making
the controls less sensitive. After stopping the
engine, the adjustment is made by removing the
bolts that hold the control rods onto the control
lever from the current holes in the control levers
and reinstalling them and the rods into the
alternate holes. The top holes closest to the
control handles are for the faster, more sensitive
setting and the bottom holes, farthest from the
control handles, are the slower, less sensitive
setting. BE SURE THE BOLTS IN THE
CONTROL RODS ARE SECURELY IN PLACE
EACH TIME YOU REMOVE THEM. You must
then perform the Tracking Adjustment described
below.
How to Perform the Tracking
Adjustment First ensure that the tire pressure is equal on
both rear drive tires (18-22 psi) and also the
front caster tires (30-40 psi). Drive the mower
on a level parking lot with the engine at full
throttle. Check that the mower drives in a
straight line when both hand controls are held to
the full speed position. If not, park the mower
and stop the engine. The adjustment is made
by loosening the jam-nuts on the control rods
(this may need to be done to one or both control
rods) and adjusting the control rods. Once the
jam-nuts are loosened at the top and bottom of
the control rod proceed to turning the control rod
clockwise or counter-clockwise. Turning the
control rod clockwise will shorten the control rod
and slow the forward movement of the mower
on that side. Turning the control rod counter-
clockwise will lengthen the control rod and
increase the speed of the forward movement of
the mower on that side.
In the “faster” Speed/Sensitivity setting (this is
the factory setting) neither rod should be
lengthened so much that at full speed it pulls the
pump control lever (on the sides of the pumps)
against the internal pump stop. Therefore, to
reach the maximum capable speed, the rods
should be lengthened one turn at a time until
you can feel, in the hand control, that the
internal pump stop has been contacted. Then
shorten the rod one turn (damage to the hydro
pump will occur if the controls are adjusted in a
way that put direct pressure on the internal
pump stop). You will feel the slight resistance.
There is no need to start the engine while
checking this incrementally. Remember, this
procedure does not apply if the Speed/
Sensitivity Adjustment is in the slower setting.
Otherwise you will wind the swivels way up the
rods and the mower will go faster but will lose
most or all of its reverse capability and then the
gap between the handlebar and the control
levers becomes excessive when at the neutral
position.
If the rod is made longer it will increase the
forward speed capability for that side of the
mower and if the rod is made shorter it will slow
down that side of the mower. So, if the mower is
tracking to the left, either the left side needs to
go faster (by lengthening the left-side rod) or the
right side needs to go slower (by shortening the
right-side rod). If the mower is tracking to the
right, either the right side needs to go faster (by
lengthening the right-side rod) or the left side
needs to go slower (by shortening the left-side
rod). It is important that neither rod should be
lengthened too far, as mentioned above.
The only reference point to limit the adjustment
from becoming extremely off is the relative
position of the pump stop and the handlebar in
the faster Speed/Sensitivity setting. Therefore, if
everything is way off either because you are
installing new parts (or other reasons) you
should only use the faster Speed/ Sensitivity
setting to get the tracking accurate and then
change to the slower speed range and adjust
the tracking only one or two turns on either side.
After getting the mower to track straight, readjust
the neutral adjustment on the pump by using a