Troy-Bilt 634F--Bronco Tiller User Manual


 
19
CHECKING AND ADJUSTING
FORWARD DRIVE BELT TENSION
It is important to maintain correct tension
on the forward drive belt. A loose belt will
cause the tines and wheels to slow down —
or stop completely — even though the en-
gine is running at full speed. A too tight
belt can result in unintentional tine move-
ment when the clutch bail is in the Neutral
(released) position.
• Check belt tension after the first two
hours of break-in operation and after every
10 operating hours.
• At the end of each tilling season, check
the belt for cracks, cuts or frayed edges
and replace it as soon as possible.
To Check Forward Belt Tension:
1. Stop engine, wait for all parts to stop
moving and disconnect spark plug wire.
2. With the Forward Clutch Bail in an open
(released) position, measure and note the
overall length of the cable spring (A, Figure
5-4) by measuring from the outermost coil
to the outermost coil.
3. Squeeze the Forward Clutch Bail
against the handlebar (see Figure 5-4) and
re-measure the length of the coils. The
belt tension is correct if this second mea-
surement is between 1/6" -to- 3/16" longer
than the first measurement.
4. If the spring is too short (less than
1/16"), the tension is too loose. If the
spring is too long (more than 3/16"), the
tension is too tight.
5. To adjust the length of the spring:
a. Release the Forward Clutch Bail.
b Unthread the hex nut (C, Figure 5-4)
halfway up the adjustment screw (D).
c. Unhook the top of the spring from
the Forward Clutch Bail.
d. Use pliers to prevent the adjuster (B)
from turning and turn the slotted screw lo-
cated inside the spring clockwise (viewed
from operator’s position) to increase ten-
sion on the spring. Turn the screw coun-
terclockwise to decrease tension. Once
adjusted, reattach the spring to the For-
ward Clutch Bail.
e. Repeat Steps 2 and 3 to re-measure
the length of the spring. When the second
measurement is between 1/16" -to- 3/16"
longer than the first measurement, retighten
the hex nut (C) against the top of the adjuster
(B).
Replacement Belt Information
If the drive belt needs to be replaced, see
your local authorized dealer or refer to the
Parts List for ordering information. Use
only a factory-authorized belt as an “over-
the-counter” belt may not perform satis-
factorily. The procedure requires average
mechanical ability and commonly available
tools.
Figure 5-3: Install tines so that cutting edge of tines enter soil first when tiller moves forward.
C
D
E
B
A
Figure 5-4: To check forward belt tension, take two measurements of the
overall length of the coils in the spring — first with the clutch bail open,
then with the clutch bail closed against the handlebar.
WARNING: Before inspecting, cleaning or servicing the machine, shut off engine, wait for all
moving parts to come to a complete stop, disconnect spark plug wire and move wire away from
spark plug. Failure to follow these instructions can result in serious personal injury or property
damage.