Instruction Manual
Page 2
... Auger 15 Starting / Stopping the Engine ........ 15 Operating Instructions 18 Releasing a Trapped Auger 19 Cleaning the Air Filter 19 Motor Management 19 Adjusting the Carburetor 20 Checking the Spark Plug 21 Engine Running Behavior 22 Lubricating the Gearbox 22 Replacing Starter Rope and Rewind Spring 23 Storing the Machine 25 Maintenance Chart 26 Main Parts and Controls 27 Specifications 28 Maintenance and Repairs 30 STIHL Incorporated...
... Auger 15 Starting / Stopping the Engine ........ 15 Operating Instructions 18 Releasing a Trapped Auger 19 Cleaning the Air Filter 19 Motor Management 19 Adjusting the Carburetor 20 Checking the Spark Plug 21 Engine Running Behavior 22 Lubricating the Gearbox 22 Replacing Starter Rope and Rewind Spring 23 Storing the Machine 25 Maintenance Chart 26 Main Parts and Controls 27 Specifications 28 Maintenance and Repairs 30 STIHL Incorporated...
Instruction Manual
Page 3
... this manual. 2 BT 121 As a result, engineering changes and improvements are marked with different features. In addition to property. Therefore some changes, modifications and improvements may improve the operator's understanding of an accident or personal injury or serious damage to the operating instructions, this manual, please contact your STIHL dealer for assistance. Caution where there is to continually improve all models...
... this manual. 2 BT 121 As a result, engineering changes and improvements are marked with different features. In addition to property. Therefore some changes, modifications and improvements may improve the operator's understanding of an accident or personal injury or serious damage to the operating instructions, this manual, please contact your STIHL dealer for assistance. Caution where there is to continually improve all models...
Instruction Manual
Page 4
... the operator or throw him to use . the earth auger 3. BT 121 3 Be alert - The transfer of rotational (reactive) forces can cause the auger powerhead and handles to rotate suddenly in a counterclockwise direction and can result in serious injury. !Warning! Never let the earth auger run unattended. Because an earth auger is a high-torque, gasolinepowered tool, some special safety...
... the operator or throw him to use . the earth auger 3. BT 121 3 Be alert - The transfer of rotational (reactive) forces can cause the auger powerhead and handles to rotate suddenly in a counterclockwise direction and can result in serious injury. !Warning! Never let the earth auger run unattended. Because an earth auger is a high-torque, gasolinepowered tool, some special safety...
Instruction Manual
Page 6
...). !Warning! Never modify an earth auger in use with ANSI Z 87.1 (or your power tool to the auger, but may be colorless and odorless. Use of head injuries. !Warning! THE USE OF THE EARTH AUGER Transporting the earth auger !Warning! By hand: Carry the earth auger with the engine running . BT 121 5 Your earth auger produces toxic exhaust fumes...
...). !Warning! Never modify an earth auger in use with ANSI Z 87.1 (or your power tool to the auger, but may be colorless and odorless. Use of head injuries. !Warning! THE USE OF THE EARTH AUGER Transporting the earth auger !Warning! By hand: Carry the earth auger with the engine running . BT 121 5 Your earth auger produces toxic exhaust fumes...
Instruction Manual
Page 7
..., change your owner's manual). !Warning! Use extreme caution when handling gasoline or fuel mix. Fuel your earth auger in your clothing immediately. 6 BT 121 Never remove the fuel filler cap while the engine is fixed and spilled fuel has been wiped away. If fuel or oil leakage is found, do not start or run the engine until leak is running. Control dust...
..., change your owner's manual). !Warning! Use extreme caution when handling gasoline or fuel mix. Fuel your earth auger in your clothing immediately. 6 BT 121 Never remove the fuel filler cap while the engine is fixed and spilled fuel has been wiped away. If fuel or oil leakage is found, do not start or run the engine until leak is running. Control dust...
Instruction Manual
Page 8
... improperly tightened fuel filler cap to the throttle trigger, throttle trigger interlock, stop switch, drilling tool and auger brake and their proper function. !Warning! Injury could result. BT 121 7 Check the condition and the tightness of fuel. It should be used during starting your earth auger for information on engagement of the auger / powerhead when the brake activating lever is damaged, improperly adjusted...
... improperly tightened fuel filler cap to the throttle trigger, throttle trigger interlock, stop switch, drilling tool and auger brake and their proper function. !Warning! Injury could result. BT 121 7 Check the condition and the tightness of fuel. It should be used during starting your earth auger for information on engagement of the auger / powerhead when the brake activating lever is damaged, improperly adjusted...
Instruction Manual
Page 9
... speed at starting . Important Adjustments !Warning! If you cannot set the correct idle speed, have your STIHL dealer check your owner's manual. In such a situation, some or all of the rotational force (reactive force) is transferred to rotate suddenly in heavy clay soil, bore about 1/3 way and remove the auger from a turning drilling tool do not use an earth auger with incorrect idle speed adjustment...
... speed at starting . Important Adjustments !Warning! If you cannot set the correct idle speed, have your STIHL dealer check your owner's manual. In such a situation, some or all of the rotational force (reactive force) is transferred to rotate suddenly in heavy clay soil, bore about 1/3 way and remove the auger from a turning drilling tool do not use an earth auger with incorrect idle speed adjustment...
Instruction Manual
Page 10
...! Your model earth auger is not insulated. !Warning! In order to the ground. Make sure your earth auger firmly to release the throttle completely if the forces become too great. BT 121 9 Wrap your fingers tightly around the handles, keeping the handles cradled between your hands in severe jerking and loss of electrical shock. DANGER! Before drilling, obtain the...
...! Your model earth auger is not insulated. !Warning! In order to the ground. Make sure your earth auger firmly to release the throttle completely if the forces become too great. BT 121 9 Wrap your fingers tightly around the handles, keeping the handles cradled between your hands in severe jerking and loss of electrical shock. DANGER! Before drilling, obtain the...
Instruction Manual
Page 11
... nonapproved replacement parts were used, STIHL may cause hearing loss. Keep spark plug and wire connections tight and clean. !Warning! Never touch a hot muffler or burn will result. Maintenance, Repair and Storing Maintenance, replacement, or repair of your STIHL servicing dealer only. !Warning! Follow the maintenance and repair instructions in a high or locked place, away from stepping in good condition. Tighten all nuts, bolts and screws except the carburetor adjustment screws...
... nonapproved replacement parts were used, STIHL may cause hearing loss. Keep spark plug and wire connections tight and clean. !Warning! Never touch a hot muffler or burn will result. Maintenance, Repair and Storing Maintenance, replacement, or repair of your STIHL servicing dealer only. !Warning! Follow the maintenance and repair instructions in a high or locked place, away from stepping in good condition. Tighten all nuts, bolts and screws except the carburetor adjustment screws...
Instruction Manual
Page 13
...12 BT 121 We recommend STIHL 50:1 two-stroke engine oil since it is stored should be cleaned as well. The machine's fuel tank and the canister in which fuel mix is specially formulated for use in both water cooled and air cooled engines (e.g., outboard motors, ...turn, increases the risk of 89 (R+M/2). Do not use BIA or TCW rated (twostroke water cooled) mix oils or other mix oils that are for use only nationally recognized high-quality unleaded gasoline! Take care when handling gasoline. This could cause running problems or even damage the engine. Avoid direct...
...12 BT 121 We recommend STIHL 50:1 two-stroke engine oil since it is stored should be cleaned as well. The machine's fuel tank and the canister in which fuel mix is specially formulated for use in both water cooled and air cooled engines (e.g., outboard motors, ...turn, increases the risk of 89 (R+M/2). Do not use BIA or TCW rated (twostroke water cooled) mix oils or other mix oils that are for use only nationally recognized high-quality unleaded gasoline! Take care when handling gasoline. This could cause running problems or even damage the engine. Avoid direct...
Instruction Manual
Page 18
...to position B. If the engine still does not start : If you did not turn the choke knob to e quickly enough after the engine began to fire, the combustion chamber has flooded. : Turn the choke knob to e : Set the slide control, trigger interlock and throttle trigger to idle speed. : Open throttle slightly - Make sure the ... : Disengage the auger brake by moving the activating lever to 20 pulls may be necessary. the auger must not rotate when the engine is correctly adjusted - warm up As soon as the engine runs: : Blip the throttle trigger to clear the combustion chamber. : Fit the spark...
...to position B. If the engine still does not start : If you did not turn the choke knob to e quickly enough after the engine began to fire, the combustion chamber has flooded. : Turn the choke knob to e : Set the slide control, trigger interlock and throttle trigger to idle speed. : Open throttle slightly - Make sure the ... : Disengage the auger brake by moving the activating lever to 20 pulls may be necessary. the auger must not rotate when the engine is correctly adjusted - warm up As soon as the engine runs: : Blip the throttle trigger to clear the combustion chamber. : Fit the spark...
Instruction Manual
Page 21
... one turn the low speed screw (L) down the engine. : Remove the auger from the machine. : Check air filter and clean or replace as stop - Drilling spindle rotates when engine is idling : Turn the idle speed screw (LA) counterclockwise until the engine runs smoothly - Adjusting Idle Speed Engine stops while idling : Carry out standard setting with the low speed screw (L). : Turn the idle speed screw (LA) clockwise until the drilling spindle stops rotating - Standard Setting : Shut...
... one turn the low speed screw (L) down the engine. : Remove the auger from the machine. : Check air filter and clean or replace as stop - Drilling spindle rotates when engine is idling : Turn the idle speed screw (LA) counterclockwise until the engine runs smoothly - Adjusting Idle Speed Engine stops while idling : Carry out standard setting with the low speed screw (L). : Turn the idle speed screw (LA) clockwise until the drilling spindle stops rotating - Standard Setting : Shut...
Instruction Manual
Page 22
These factors cause deposits to form on power, difficult to start or runs poorly at part load. BT 121 21 Fit a new spark plug after every correction to change the setting of the approved range. see "Specifications". : Use only resistor type spark plugs of the idle speed screw (LA) after approx. 100 operating hours or earlier if the electrodes are badly eroded. Wrong fuel mix...
These factors cause deposits to form on power, difficult to start or runs poorly at part load. BT 121 21 Fit a new spark plug after every correction to change the setting of the approved range. see "Specifications". : Use only resistor type spark plugs of the idle speed screw (LA) after approx. 100 operating hours or earlier if the electrodes are badly eroded. Wrong fuel mix...
Instruction Manual
Page 25
... that it must still be under "Replacing a Broken Starter Rope". English / USA 7 7 Tensioning the Rewind Spring : Make a loop in the unwound starter rope and use it in the clockwise direction, starting outside and working inward. : Fit the screws. : Install the rope rotor as described under tension and could break. : Take one more turn on rope rotor to rotate the...
... that it must still be under "Replacing a Broken Starter Rope". English / USA 7 7 Tensioning the Rewind Spring : Make a loop in the unwound starter rope and use it in the clockwise direction, starting outside and working inward. : Fit the screws. : Install the rope rotor as described under tension and could break. : Take one more turn on rope rotor to rotate the...
Instruction Manual
Page 27
...-lubricate Drilling spindle Clean X Auger Inspect X Replace Safety labels Replace 1) STIHL recommends the STIHL servicing dealer X X X X X X X X X X X X X X X x 26 BT 121 If your daily working time is longer than normal or conditions are difficult (very dusty work or daily after each refueling stop weekly monthly yearly if problem if damaged as required English / USA Maintenance Chart Please note that the following maintenance intervals apply for normal operating conditions. before starting work...
...-lubricate Drilling spindle Clean X Auger Inspect X Replace Safety labels Replace 1) STIHL recommends the STIHL servicing dealer X X X X X X X X X X X X X X X x 26 BT 121 If your daily working time is longer than normal or conditions are difficult (very dusty work or daily after each refueling stop weekly monthly yearly if problem if damaged as required English / USA Maintenance Chart Please note that the following maintenance intervals apply for normal operating conditions. before starting work...
Instruction Manual
Page 29
... tank. 5. Throttle Trigger Controls the speed of operating hours for which is the device to stop . Screw Plug Seals filler opening for easier engine starts. 14. Choke Knob Operates choke to ISO 8893 Max. Auger Brake Activating Lever Lever for a cold start the engine. 2. Padding Helps cushion thigh against handle frame. Air Filter Cover Encloses and protects the air filter. 4. Slide Control For starting , switches the engine's ignition...
... tank. 5. Throttle Trigger Controls the speed of operating hours for which is the device to stop . Screw Plug Seals filler opening for easier engine starts. 14. Choke Knob Operates choke to ISO 8893 Max. Auger Brake Activating Lever Lever for a cold start the engine. 2. Padding Helps cushion thigh against handle frame. Air Filter Cover Encloses and protects the air filter. 4. Slide Control For starting , switches the engine's ignition...
Instruction Manual
Page 30
...gear drive Gear ratio 47.5 : 1 Max. torque at drilling spindle 79 Nm Lubrication STIHL gear lubricant for all markets) Electrode gap 0.02 in (0.5 mm) Spark plug thread M 14 x 1.25; 0.37 in (9.5 mm) long Fuel System Carburetor All position diaphragm carburetor with electronic speed governor Spark plug (resistor type) Bosch WSR 6 F, NGK BPMR 7 A or Champion RCJ 6 Y (not for brushcutters Weight without drilling tool... auger 6 in (150 mm) diameter, 20.6 in (525 mm) long Special Accessories Shaft extension 17.7 in (450 mm) long Chuck For drill diameters from 5/64" to 1/2" (2 to 13 mm) BT 121 29
...gear drive Gear ratio 47.5 : 1 Max. torque at drilling spindle 79 Nm Lubrication STIHL gear lubricant for all markets) Electrode gap 0.02 in (0.5 mm) Spark plug thread M 14 x 1.25; 0.37 in (9.5 mm) long Fuel System Carburetor All position diaphragm carburetor with electronic speed governor Spark plug (resistor type) Bosch WSR 6 F, NGK BPMR 7 A or Champion RCJ 6 Y (not for brushcutters Weight without drilling tool... auger 6 in (150 mm) diameter, 20.6 in (525 mm) long Special Accessories Shaft extension 17.7 in (450 mm) long Chuck For drill diameters from 5/64" to 1/2" (2 to 13 mm) BT 121 29
Instruction Manual
Page 31
Warranty claims following repairs can be identified by the STlHL part number, the STIHl logo and, in this manual. Other repair work may appear alone on small parts. 30 BT 121 This symbol may be accepted only if the repair has been performed by authorized STIHL service shops. Original STlHL parts can be performed only by an authorized STIHL servicing dealer using original STIHL replacement parts. English / USA Maintenance and Repairs Users of this unit should carry out only the maintenance operations described in some cases, by the STlHL parts symbol (.
Warranty claims following repairs can be identified by the STlHL part number, the STIHl logo and, in this manual. Other repair work may appear alone on small parts. 30 BT 121 This symbol may be accepted only if the repair has been performed by authorized STIHL service shops. Original STlHL parts can be performed only by an authorized STIHL servicing dealer using original STIHL replacement parts. English / USA Maintenance and Repairs Users of this unit should carry out only the maintenance operations described in some cases, by the STlHL parts symbol (.
Instruction Manual
Page 32
... your equipment type engine. Owner's Warranty Responsibilities: As the small off-road equipment engine owner, you warranty coverage if your small off -road equipment engine or a part has failed due to STIHL Inc., 536 Viking Drive, P.O. Warranty Period The warranty period will repair your owner's manual. Any replacement part or service that your small off -road equipment engine owner, you can write to abuse, neglect, improper maintenance or...
... your equipment type engine. Owner's Warranty Responsibilities: As the small off-road equipment engine owner, you warranty coverage if your small off -road equipment engine or a part has failed due to STIHL Inc., 536 Viking Drive, P.O. Warranty Period The warranty period will repair your owner's manual. Any replacement part or service that your small off -road equipment engine owner, you can write to abuse, neglect, improper maintenance or...
Instruction Manual
Page 33
... fuel-oil mixture (see also instruction "Fuel"). Deviations from this manual are based on the application of parts and other engine components caused by STIHL Incorporated at and after the first scheduled replacement point. 32 BT 121 Diagnosis You, as necessary" will be warranted for required maintenance at no cost to the owner. Warranty Work STIHL Incorporated shall remedy warranty defects at an authorized STIHL servicing dealer...
... fuel-oil mixture (see also instruction "Fuel"). Deviations from this manual are based on the application of parts and other engine components caused by STIHL Incorporated at and after the first scheduled replacement point. 32 BT 121 Diagnosis You, as necessary" will be warranted for required maintenance at no cost to the owner. Warranty Work STIHL Incorporated shall remedy warranty defects at an authorized STIHL servicing dealer...