Bolens 390 - Manual (Page 7)

DONTROLLING SPEED AND TILLING DEPTH
1. Wheel Yoke Adjustment: Place wheel yoke so
that the wheels are forward (nearest point
between wheels and tines) for shallow tilling, culti­
vating and transport. The forward speed will
increase. Turn yoke around (farthest point
between wheels and tines) for deep tilling. For­
ward speed will decrease. (See Figure 8)
2. Depth Stake Adjustment: The depth stake acts
as a brake for the tiller and controls the depth and
speed at which the machine will operate. Remove
the clevis pin and hairpin clip to raise or lower
depth stake. (See Figure 7)
By increasing the depth of the depth stake, the forward
speed of the machine is reduced, and the working
depth is increased. (See Figure 9) When the depth
stake is raised, the working depth of the machine is
reduced and the forward speed is increased. The
working depth of the machine may be predetermined
by setting the depth stake and wheels so that the
wheels are about four inches from the ground when
the tines and depth stake are resting on the ground.
This setting will permit a working depth of about four
inches. When presetting the working depth, the han­
dles should be adjusted so the hand grips are a little
above waist height because the tiller will be lower
when the tines and depth stake penetrate the ground.
When tilling, leave approximately 8 inches of unfilled
soil between the first and second tilling paths, then
make the third path between the first and second as
shown in figure 10. In some soils, the desired depth is
obtained the first time over the garden. In other soils,
the desired depth is obtained by going over the garden
two or three times. In the latter case, the depth stake
should be lowered before each succeeding pass over
the garden. Passes should be made across the length
and width of the garden alternately. Rocks which are
turned up should be removed from the garden area.
Figure 10.
3. Handle Pressure: Further control of tilling depth
and travel speed can be obtained by variation of
pressure on the handles. A downward pressure
on the handles will reduce the working depth and
increase the forward speed. An upward pressure
on the handles will increase the working depth
and reduce the forward speed. The type of soil
and working conditions will determine the actual
setting of the depth stake and the handle pressure
required.
4. Throttle Control: The throttle control lever adjusts
the engine speed and stops the engine. With the
throttle control lever pushed completely forward,
the carburetor is in START position. Pulling the
throttle control back slightly adjusts the engine
speed to FAST. Pulling the throttle back further