Simplicity CFC Series Operator's Manual page 43

Adjustments
FORWARD TRAVEL STOP
The adjustment bolt (A, figure 25) can be rotated to limit the
maximum output speed of each hydro pump so that the rider
will travel in a straight direction at full forward ground speed.
For hydro output speed variation at less than full forward
position, refer to 'Transmission Speed Variation
Adjustment".
For double-chain reduction models, turn the bolt all the way
out. With ground speed control set to full forward position,
turn the bolt in until it contacts the frame. Turn the bolt an
additional 1/2 turn so that internal hydro pump components
are not used as the forward travel stop.
For single-chain reduction models, adjust the bolt so drive
wheels are turning 130 rpm maximum.
The left or right adjustment bolt can be turned inward an
additional amount required to limit the output speed of a
faster hydro pump if there is noticeable difference at
maximum forward speed.
If unit is equipped with set collar (C, figure 25), turning the
adjustment bolt will affect the reverse travel stop. (Some
early model lever-steer units did not require set collar.)
Perform the "Reverse Travel Stop Adjustment" to reposition
the set collar if forward travel stop Is adjusted.
Figure 25.
A. Adjustment Boil
B. Hydro Input Linkage
C. Set Collar
41