Troy-Bilt TB70SS, Operator'S Manual

NOTE:

The unit uses Spring Assist Starting™, which
significantly reduces the effort required to start
the engine. You must pull the starter rope out far
enough to hear the engine attempt to start. There
is no need to pull the rope briskly-- there is no
harsh resistance when pulling. Be aware that this
starting method is vastly different from (and
much easier than) what you may be used to.

5.

Place the blue choke lever in Position 2 (Fig. 8).

6.

While squeezing the throttle control, pull the starter rope
out with a controlled and steady motion until the engine
starts.

7.

Keep the throttle squeezed and allow the engine to
warm up for 15 to 30 seconds.

NOTE:

Engine may take longer to warm up and reach
maximum operating speed at colder
temperatures.

NOTE:

Unit is properly warmed up when engine
accelerates without hesitation.

8.

Once the engine is warmed up, place the blue choke
lever in Position 3 (Fig. 8).  The unit is ready for use.

IF...

the engine hesitates, return the blue choke lever to
Position 2 (Fig. 8) and continue warm-up.

IF...

the engine does not start, go back to step 2.  

IF...

the engine fails to start after a few attempts, place the
blue choke lever in Position 3 and squeeze the throttle
control. Pull the starter rope out with a controlled and
steady motion 3 to 8 times. The engine should start. If
not, repeat.

IF WARM...

If the engine is already warm, start the unit with

the blue choke lever in Position 2. After the unit
starts, move the blue choke lever to Position 3. 

STOPPING INSTRUCTIONS

1.

Release your finger from the throttle control. Allow
the engine to cool down by idling.

2.

Press and hold On/Off Stop Control in the OFF (O) position until engine comes to a
complete stop (Fig. 7).

Stop/Off (O)

Throttle

Control

Start/On (I)

Fig. 7

Starting

Position

Throttle Control

Fig. 9

Position 1

Position 3

Position 2

Blue Choke

Lever

Fig. 8

Primer Bulb

Trimmer

Equipped With

Spring Assist

Starting ™ 

ASSEMBLY INSTRUCTIONS

2.

Press and hold the release button (Fig. 4).

3.

While firmly holding the upper shaft housing, pull the cutting
attachment or add-on straight out of the EZ-Link™ coupler (Fig. 5).

INSTALLING THE CUTTING ATTACHMENT OR ADD-ONS

NOTE:

To make installing or removing the add-on 
easier, place the unit on the ground or on a work
bench.

1.

Turn knob counterclockwise to loosen (Fig. 4).

2.

While firmly holding the add-on, push it straight into the EZ-
Link™ coupler (Fig. 5).

NOTE:

Aligning the release button with the guide recess will
help installation (Fig. 4).

3.

Turn the knob clockwise to tighten (Fig. 6).

For decorative trimming/edging with the 

line head cutting attachment

, lock the release button of the

cutting attachment into the 90° hole  (Fig. 6).

Guide Recess

Fig. 4

Release

Button

EZ-Link

™

Coupler

Upper Shaft

Housing

Fig. 5

Lower Shaft

Housing

Primary Hole

Knob

Fig. 6

90˚ Edging Hole

(Trimmer Only)

OIL AND FUEL INFORMATION

OIL AND FUEL MIXING INSTRUCTIONS

Old and/or improperly mixed fuel are the main reasons for the unit not running properly. Be sure to use
fresh, clean unleaded fuel. Follow the instructions carefully for the proper fuel/oil mixture.

Definition of Blended Fuels

Today's fuels are often a blend of gasoline and oxygenates such as ethanol, methanol, or MTBE (ether).
Alcohol-blended fuel absorbs water. As little as 1% water in the fuel can make fuel and oil separate. It
forms acids when stored. When using alcohol-blended fuel, use fresh fuel (less than 60 days old).

Using Blended Fuels

If you choose to use a blended fuel, or its use is unavoidable, follow recommended precautions:
•

Always use the fresh fuel mix explained in your operator's manual

•

Always agitate the fuel mix before fueling the unit

•

Drain the tank and run the engine dry before storing the unit

Using Fuel Additives

The bottle of 2-cycle oil that came with your unit contains a fuel additive which will help inhibit corrosion
and minimize the formation of gum deposits. It is recommended that you use our 2-cycle oil with this unit.
If unavailable, use a good 2-cycle oil de-signed for air-cooled engines along with a fuel additive, such as
STA-BIL® Gas Stabilizer or an equivalent. Add 0.8 oz. (23 ml.) of fuel additive per gallon of fuel according
to the instructions on the container. NEVER add fuel additives directly to the unit's fuel tank.

Thoroughly mix the proper ratio of 2-cycle engine oil with
unleaded gasoline in a separate fuel can. Use a 40:1 fuel/oil
ratio. Do not mix them directly in the engine fuel tank. See the
table below for specific gas and oil mixing ratios.

NOTE:

One gallon (3.8 liters) of unleaded gasoline mixed
with one 3.2 oz. (95 ml.) bottle of 2-cycle oil makes
a 40:1 fuel/oil ratio.

NOTE:

Dispose of the old fuel/oil mix in accordance to
Federal, State and Local regulations.

MIXING RATIO - 40:1

UNLEADED GAS

2 CYCLE OIL

1 GALLON US

(3.8 LITERS)

3.2 FL. OZ.

(95 ml) 

1 LITER

25 ml

STARTING/STOPPING INSTRUCTIONS

STARTING INSTRUCTIONS

1.

Mix gas with oil. Fill fuel tank with fuel/oil mixture. See Oil and Fuel Mixing Instructions.

NOTE:

There is no need to turn the unit on. The On/Off Stop Control is in the ON ( I ) position
at all times (Fig. 7).

2.

Fully press and release the primer bulb 10 times, slowly. Some amount of fuel should be
visible in the primer bulb and fuel lines (Fig. 8). If you can’t see fuel in the bulb, press and
release the bulb as many times as it takes before you can see fuel in it.

3.

Place the blue choke lever in Position 1 (Fig. 8).

4.

Crouch in the starting position (Fig. 9), squeeze the throttle control, and pull the starter rope
out with a controlled and steady motion 5 times. 

STARTING/STOPPING INSTRUCTIONS

OPERATING INSTRUCTIONS

HOLDING THE TRIMMER

Before operating the unit, stand in the operating position (Fig. 10).
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 attachment is parallel to the ground and easily
contacts the grass without the need to bend over

ADJUSTING TRIMMING LINE LENGTH

The Bump Head™ cutting attachment allows you to release
trimming line without stopping the engine. To release more line,
lightly tap the cutting attachment on the ground (Fig. 11) while
operating the trimmer 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 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 attachment parallel to the ground.

•

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 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 trimmer 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 your 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 and more.
Rotate the whole unit so that the cutting attachment is at a 30° angle to the ground (Fig. 12).

Fig. 11

Fig. 10

Fig. 10

4

CAUTION:

For proper engine operation and maximum reliability, pay strict attention to

the oil and fuel mixing instructions on the 2-cycle oil container. Using improperly mixed
fuel can severely damage the engine.

WARNING:

Gasoline is extremely flammable.

Ignited vapors may explode. Always stop the engine
and allow it to cool before filling the fuel tank. Do not
smoke while filling the tank. Keep sparks and open
flames at a distance from the area.

WARNING:

Remove fuel cap slowly to avoid injury from fuel spray. Never operate the

unit without the fuel cap securely in place.

WARNING: 

Add fuel in a clean, well ventilated outdoor area. Wipe up any spilled fuel

immediately. Avoid creating a source of ignition for spilt fuel. Do not start the engine until
fuel vapors dissipate.

WARNING:

Avoid accidental starting. Make sure you are in the starting position when

pulling the starter rope (Fig. 8). To avoid serious injury, the operator and unit must be
in a stable position while starting.

WARNING:

Remove fuel cap slowly to avoid injury from fuel spray. Never operate the

unit without the fuel cap securely in place.

WARNING:

Always wear eye, hearing, foot and body protection to reduce the risk of injury

when operating this unit.

CAUTION:

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

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