Troy-Bilt TB80 EC Operator'S Manual Download Page 4

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HOLDING THE UNIT

Before operating the unit, stand in the operating position (Fig. 9). Check for the
following:
• The operator is wearing eye protection and proper clothing

• With a slightly-bent right arm, the operator’s hand is holding the shaft grip

• The operator’s left arm is straight, the left hand holding the D-handle

• The unit is at waist level

• The cutting head is parallel to the ground and easily contacts the grass without

the need to bend over

ADJUSTING TRIMMING LINE LENGTH

The Bump Head™ cutting head allows the release of trimming line without stopping the engine. To release more line,
lightly tap the cutting head on the ground (Fig. 10) 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 head 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 attempting a line release in tall grass, the engine may
stall. Always keep the trimming line fully extended. Line release becomes more difficult when the cutting line gets shorter.

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

TIPS FOR BEST TRIMMING RESULTS

• Keep the cutting head parallel to the ground.

• Do not force the cutting head. 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 engine.

• Cut grass over 8 inches (200 mm) by working from top to bottom in small increments to avoid premature line wear

or engine drag.

• Cut from right to left whenever possible. Cutting to the left improves the unit's cutting efficiency. Clippings are

thrown away from the operator.

• Slowly move the unit into and out of the cutting area at the desired height. Move either in a forward-backward or

side-to-side motion. Cutting shorter lengths produces the best results.

• Trim only when grass and weeds are dry.

• The life of the cutting line is dependent upon:

• Following the trimming techniques

• What vegetation is being cut

• Where vegetation is cut

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

DECORATIVE TRIMMING

Decorative trimming is accomplished by removing all vegetation around trees, posts,
fences, etc..

Rotate the whole unit so that the cutting head is at a 30° angle to the ground (Fig. 11).

MAINTENANCE AND REPAIR INSTRUCTIONS

MAINTENANCE SCHEDULE

Perform these required maintenance procedures at the frequency stated in the table. These procedures should also be
a part of any seasonal tune-up.

NOTE:

Some maintenance procedures may require special tools or skills. If you are unsure about these procedures,
take your unit to any non-road engine repair establishment, individual or authorized service dealer.

NOTE:

Maintenance, replacement, or repair of the emission control devices and system may be performed by any
non-road engine repair establishment, individual or authorized service dealer.

NOTE:

Please read the California/EPA statement that came with the unit for a complete listing of terms and
coverage for the emissions control devices, such as the spark arrestor, muffler, carburetor, etc.

WARNING:

To prevent serious injury, never perform maintenance or repairs while the unit is running.

Always allow the unit to cool before servicing or repairing the unit. Disconnect the spark plug wire to
prevent the unit from starting accidentally.

FREQUENCY

MAINTENANCE REQUIRED

SEE

Every 10 hours

Clean and re-oil air filter

p. 4

Every 25 hours

Check spark plug condition and gap

p. 5

LINE INSTALLATION

This section covers both SplitLine® and standard
single line installation.

Always use original equipment manufacturer

0.095 in.

(2.41 mm)

replacement line. Line other than the

specified may make the engine overheat or fail.

There are two methods to replace the trimming line:

• Wind the inner reel with new line

• Install a prewound inner reel

Removing the Existing Inner Reel

1. Hold the outer spool with one hand and unscrew

the bump knob counterclockwise (Fig. 12).
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. 13).

3. Remove spring from the inner reel (Fig. 13).

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. 14). If necessary,
remove burrs or replace the reel and spool.

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. 15). 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. 16). Wind the line in the direction indicated
on the inner reel. Place an index finger between
the two lines to stop the lines from overlapping.
Do not overlap the ends of the line. Proceed to
step 12.

Loop

Fig. 15

Fig. 16

Loop

Fig. 17

Indexing Teeth

Fig. 14

Index Teeth

Fig. 18

Spring

Fig. 19

Eyelets

Bolt

Bump Knob

Fig. 12

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. 17). 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. 17).

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 head to operate incorrectly.

12. Insert the ends of the line into the two holding slots (Fig. 18).

13. Insert or slide the ends of the line through or into the eyelets in the outer spool and place inner reel with spring

inside the outer spool (Fig. 19). Push the inner reel and outer spool together.

NOTE:

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

14. While holding the inner reel and outer spool, grasp the ends and pull firmly to release the line from the holding slots in the spool.

15. Hold the inner reel in place and install the bump knob by turning clockwise. Tighten securely.

INSTALLING A PREWOUND REEL

1. Hold the outer spool with one hand and unscrew the bump knob counterclockwise (Fig. 12). Inspect the bolt inside

the bump knob to make sure it moves freely. Replace the bump knob if damaged.

2. Remove the old inner reel from the outer spool (Fig. 13).

3. Remove the spring from the old inner reel (Fig. 13).

4. Place the spring in the new inner reel.

NOTE:

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

5. Insert or slide the ends of the line through or into the eyelets in the outer spool (Fig. 19).

6. Place the new inner reel inside the outer spool. 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 spool.

7. Hold the inner reel in place and install the bump knob by turning clockwise. Tighten securely.

INSTALLATION OF THE SPEEDLOCK™

Removing the Existing Inner Reel

Refer to Removing the Existing Inner Reel in the
Maintenance and Repair Instructions section that
can be found in the operator’s manual.

Installing the SpeedLock™

1. After removing the inner reel, place the

SpeedLock™ onto the shaft, making sure to
align the arrows with the eyelets in the outer
spool (Fig. 20).

2. Place the spring over the shaft and into the

recess in the SpeedLock™ Spool (Fig. 20).

3. While holding the outer spool in place, insert

the bolt located in the Bump Knob™ through
the end of the spring and into the end of the
shaft (Fig. 20).

4. While slightly compressing the spring, screw

the Bump Knob™ clockwise into the shaft (Fig.
20). Tighten Securely.

Installing the Trimming Line

1. Align the arrows on the SpeedLock™ with the

eyelets on the outer spool (Fig. 21).

2. Insert a piece of precut spiral line,

P/N 49UFSHLL953

, into an eyelet on the outer spool (Fig. 21).

3. Push the line into the SpeedLock™ until it starts to show from the opposite side.

4. Adjust the line so that both ends are of equal length (Fig. 22).

5. While holding the outer spool in place, pull the SpeedLock™ away from the outer spool and twist the SpeedLock™

clockwise until the dot is in line with the eyelet or until it stops (Fig. 23).

6. Release the SpeedLock™ so that it snaps into place.

7. Check that the SpeedLock™ has seated completely into the outer spool. If it has not, repeat steps 5 thru 7.

Removing the Trimming Line

1. While holding the outer spool in place, pull the SpeedLock™ away from the outer spool and twist the SpeedLock™

counterclockwise until it stops. The arrows should align with the eyelets on the outer spool. (Fig. 21)

2. Release the SpeedLock™.

NOTE:

The SpeedLock™ should stand about 1/4 of an inch above the outer spool.

3. Firmly pull one end of the trimming line until the whole piece exits the outer spool.

REMOVING THE SPEEDLOCK™

1. While holding the outer spool in place, turn the Bump Knob™ counterclockwise until it completely unscrews from

the shaft.

2. Remove the spring.

3. Remove the SpeedLock™.

AIR FILTER MAINTENANCE

Cleaning the Air Filter

Failure to maintain your air filter properly can result in poor performance or can cause
permanent damage to your engine.
1. Open the air filter cover by unscrewing the cover screw (Fig. 24).

2. Remove the air filter (Fig. 24).

3. Wash the filter in detergent and water. Rinse the filter thoroughly and allow it to

dry.

4. Apply enough clean SAE 30 motor oil to lightly coat the filter.

5. Squeeze the filter to spread and remove excess oil.

6. Replace the air filter (Fig. 24).

NOTE:

Operating the unit without the air filter will VOID the warranty.

7. Reinstall the air filter cover. Insert the hooks on the air filter housing into the slots

on the air filter cover (Fig. 25).

8. Swing the air filter cover to the right and align the cover screw with the cover

screw hole (Fig. 25). Tighten the cover screw to secure the air filter cover.

NOTE:

Do not over tighten as this may strip the screw.

ADJUSTING THE IDLE SPEED

NOTE:

Careless adjustments can seriously damage the unit. A qualified service
dealer should make carburetor adjustments.

If, after checking the fuel and cleaning the air filter, the engine still will not idle, adjust
the idle speed screw as follows:
1. Start the engine. Refer to

Starting and Stopping

2. Release the throttle control and let the engine idle. If the engine stops, use a small

Phillips screwdriver to turn the idle speed screw clockwise, 1/8 of a turn at a time
(as needed) until the engine idles smoothly (Fig. 26).

3. If the engine is idling too quickly, turn the idle speed screw counterclockwise, 1/8

of a turn at a time (as needed) to reduce the idle speed (Fig. 26).

Checking the fuel, cleaning the air filter, and adjusting the idle speed should solve
most engine problems. If not, and any of the following conditions are true, take the
unit to a qualified service dealer:
• the engine will not idle

• the engine hesitates or stalls on acceleration

• there is a loss of engine power

WARNING:

To avoid serious personal injury, always stop the engine and allow it to cool before

cleaning or maintaining the unit.

WARNING:

The cutting head may spin during idle speed adjustments. Wear protective clothing and

observe all safety instructions to prevent serious personal injury.

WARNING:

Never use metal-reinforced line, wire, chain or rope. These can break off and become

dangerous projectiles.

Fig. 26