Troy-Bilt TB138PS Operator'S Manual Download

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OPERATING THE UNIT AS A TRIMMER

1. Hold the unit at waist level with the cutting attachment

parallel to the ground so that it easily contacts the grass
without the need to bend over (Fig. 14).

2. Start the motor. Refer to

Starting and Stopping Instructions

3. Slowly move the cutting attachment into and out of the

cutting area at the desired height.

• Move either in a forward-backward or side-to-side

motion. When cutting from side-to-side, cut from right to
left whenever possible. This improves the unit’s cutting
efficiency and directs clippings away from the operator.

• Cutting shorter lengths produces the best results.
• Cut grass over 8 inches (200 mm) by working from top

to bottom in small increments to avoid premature line
wear or motor drag.

• Do not force the cutting attachment. Allow the tip of the

line to do the cutting, especially along walls. Cutting
with more than the tip will reduce cutting efficiency and
may overload the motor.

• Only trim when grass or weeds are dry.

4. Dispose of debris appropriately.

Decorative Trimming

Decorative trimming is the act of removing all vegetation
from around trees, posts, fences, etc. To accomplish it,
rotate the whole unit so that the cutting attachment is at a
30˚ angle to the ground (Fig. 15).

Adjusting the Trimming Line Length

The Bump Head

cutting attachment allows the release of

trimming line without having to stop the motor. To release
more line, lightly tap the cutting attachment to the ground
(Fig. 16) while operating the unit at high speed.

NOTE:

Always keep the trimming line fully extended.
Line release becomes more difficult when the
cutting line gets shorter.

Each time the head is bumped, about 1 inch (25.4 mm) of
trimming line releases. A blade in the cutting attachment
shield will cut the line to the proper length if any excess line
is released.
For best results, tap the bump knob on bare ground or hard soil. If you attempt a line release in tall
grass, the motor may stall.

NOTE:

Do not rest the Bump Head

on the ground while the unit is running.

Some line breakage will occur from:

• Entanglement with foreign matter
• Normal line fatigue
• Attempting to cut thick, stalky weeds
• Forcing the line into objects such as walls or fence posts

The life of the cutting line is dependent upon:

• Following these trimming instructions
• What vegetation is being cut
• Where vegetation is being cut

For example, the line will wear faster when trimming against a foundation wall than when trimming
around a tree.

OPERATING THE UNIT AS A POLE SAW

Preparation for Cutting

• To prevent electrocution, do not operate within 50 feet

(15 m) of overhead electrical lines (Fig. 17).

• Keep everyone – helpers, bystanders, children and

animals – at least 50 feet (15 m) away from the work area
(Fig. 17). If anyone enters the work area, stop the unit!

• Wear non-slip gloves for maximum grip and protection.
• Maintain a proper grip on the unit whenever the motor is

running. Hold the unit firmly with both hands. Firmly grip
the shaft grip with the right hand and the D-handle with
the left hand (Fig. 18).

• The operator should be to the left of the chain line. Never

use a left-handed (cross-handed) grip, or any stance that
places any body part across the chain line (Fig. 18).

• Never stand directly under the limb being cut.

Pruning

This unit is designed for trimming small branches and limbs
up to 4 inches (10 cm) in diameter. For best results, observe
the following precautions.
• Do not use the pole saw for cutting down trees.
• Plan the cut carefully. Be aware of the direction in which the branch will fall.
• Branches may fall in unexpected directions. Do not stand directly under the branch being cut (Fig. 18).
• Do not cut from a ladder; this is extremely dangerous. Leave this operation for professionals.
• The most typical cutting application is to position the unit at an angle of 60° or less, depending on

the specific situation (Fig. 18). As the angle of the pole saw shaft to the ground increases, the
difficulty of making the first cut (from the underside of the limb) increases.

• Remove long branches in several stages.
• Do not make the flush cut next to the main limb or trunk until the limb has been cut further out to

reduce the weight.

• Cut lower branches first to allow the top branches more room to fall.
• Work slowly, keeping both hands on the unit with a firm grip. Maintain secure footing and balance.
• Avoid kickback. Kickback can result in severe injury or death. See

Understanding Kickback

and

Kickback Safety Precautions

in the Safety Instructions section.

• Keep the unit running the entire time while cutting, making sure to maintain a steady speed.
• Allow the chain to do the cutting; exert only light downward pressure. Forcing the cut could result in

damage to the guide bar, chain or motor.

• Release the trigger as soon as the cut is completed. Allow the chain to come to a complete stop.

Unnecessary wear may occur to the chain, bar and unit if the saw is run without a cutting load.

• Do not put pressure on the saw at the end of the cut.

Fig. 15

(15 m)

Fig. 17

OPERATING INSTRUCTIONS

Fig. 14

Fig. 16

WARNING:

Do not remove or alter the line cutting blade assembly. Excessive line length

will make the motor overheat. This may lead to serious personal injury or damage to the unit.

OPERATING INSTRUCTIONS

Basic Cutting Procedure

Follow the steps below to prevent stripping the bark from
the main member of the tree or shrub.

Do not use a back-

and-forth sawing motion.

1. Start the motor and let the chain accelerate to full speed

before starting the cut. Refer to

Starting and Stopping

Instructions

2. Make a shallow first cut (1/4 of the limb’s diameter) on

the underside of the limb close to the main limb or trunk
(Fig. 19).

3. Make a second cut from the top side of the limb

outboard from the first cut. Continue the cut through the
limb until the limb separates from the tree. Be prepared
to balance the weight of the tool when the limb falls.

4. Make a final cut close to main limb or trunk.

NOTE:

For second and final cuts (from the top of the
limb or branch), hold the front cutting guide
against the limb being cut (Fig. 20). This will help
steady the limb and make it easier to cut. Allow
the chain to do the cutting; only exert light
downward pressure. If the cut is forced, damage
to the bar, chain or motor may result.

5. Release the trigger as soon as the cut is completed.

Failure to follow proper cutting procedures will result in
the bar and chain binding and becoming pinched or
trapped in the limb. If this should happen:

• Stop the motor and disconnect the unit from the power source.
• If the limb can be reached from the ground, lift the limb while holding the saw. This should release

the “pinch” and free the saw.

• If the saw is still trapped, call a professional for assistance.

Fig. 18

Fig. 19

Fig. 20

Load

First Cut

1/4 Diameter

Cutting

Guide

Final Cut

Second Cut

WARNING:

Use caution when pruning heavy

branches. Falling branches can cause serious
injury. Always wear head protection, plan a safe
exit from the path of falling limbs and stay alert.

MAINTENANCE AND REPAIR INSTRUCTIONS

NOTE:

If it is necessary to replace damaged or missing
parts, use only manufacturer suggested
replacement parts. The use of any other parts
may create a hazard or cause product damage
and will VOID the warranty.

TRIMMER MAINTENANCE AND REPAIR

Line Installation

This section covers both SplitLine

and standard single

line installation.

Always use original equipment manufacturer 0.080 in. (2.03
mm) replacement line. Line other than the specified may
make the motor overheat or fail.

There are two methods for replacing the trimming line:
• Wind the inner reel with new line
• Install a prewound inner reel

Winding New Line on the Existing Inner Reel

1. Hold the outer spool with one hand and unscrew the

bump knob counterclockwise (Fig. 21). Inspect the bolt
inside the bump knob to make sure it moves freely.
Replace the bump knob if damaged.

2. Remove the inner reel from the outer spool (Fig. 22).
3. Remove spring from the inner reel (Fig. 22).
4. Use a clean cloth to clean the inner reel, spring, shaft

and inner surface of the outer spool.

5. Check the indexing teeth on the inner reel and outer

spool for wear (Fig. 23). If necessary, remove burrs or
replace the reel and spool.

NOTE:

SplitLine™ can only be used with the inner reel
with the slotted holes. Single line can be used on
either type of inner reel. Use Figure 24 to identify
the inner reel you have.

NOTE:

Always use the correct line length when installing
trimming line on the unit. The line may not release
properly if the line is too long.

Single Line Installation

Go To Step 8 for SplitLine™ Installation

6. Take approximately 20 feet (6 m) of new trimming line,

loop it into two equal lengths. Insert each end of the line
through one of the two holes in the inner reel (Fig. 25).
Pull the line through the inner reel so that the loop is as
small as possible.

7. Wind the lines in tight even layers, onto the reel (Fig. 26).

Wind the line in the direction indicated on the inner reel.
Place your index finger between the two lines to stop
the lines from overlapping. Do not overlap the ends of
the line. Proceed to step 11.

SplitLine™ Installation

8. Take approximately 10 feet (3 m) of new trimming line.

Insert one end of the line through one of the two holes in
the inner reel (Fig. 27). Pull the line through the inner reel
until only about 4 inches is left out.

9. Insert the end of the line into the open hole in the inner

reel and pull the line tight to make the loop as small as
possible(Fig. 27).

10. Before winding, split the line back about 6 inches.
11. Wind the line in tight even layers in the direction

indicated on the inner reel.

NOTE:

Failure to wind the line in the direction indicated
will cause the cutting attachment to operate
incorrectly.

12. Insert the ends of the line into the two holding slots (Fig. 28).
13. Insert the ends of the line through the eyelets in the

outer spool and place inner reel with spring inside the
outer spool(Fig. 29). Push the inner reel and outer spool
together. While holding the inner reel and outer spool,
grasp the ends and pull firmly to release the line from the
holding slots in the reel.

NOTE:

The spring must be assembled on the inner reel
before reassembling the cutting attachment.

14. Hold the inner reel in place and install the bump knob

by turning clockwise. Tighten securely.

WARNING:

Before inspecting, cleaning or servicing the unit, stop the motor, wait for all

moving parts to stop, disconnect the unit from the power source and allow the unit to cool.
Failure to follow these instructions can result in serious injury or property damage.

Fig. 21

Bolt

Fig. 22

Outer Spool

Fig. 23

Indexing Teeth

Fig. 24

For Use with

SingleLine

ONLY

Fig. 25

Loop