Stihl FR 108 Owner'S Manual Download Page 1

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Summary of Contents for FR 108

Page 1: ...STIHL FS BB 7DB Instruction Manual Owner s Manual Assembling Safety Precautions Operating Instructions Maintenance ...

Page 2: ...4 scratcher tooth 47 not understand any of the instructions in Fitting stop 24 Replacing Starter Rope and this manual Mounting the Cutting Tools 25 Rewind Spring 48 STIHL Supercut 2 2 26 Spark Arresting Screen in Warn ng STIHL Supercut 20 2 26 Muffler 51 Because a brushcutter is a high speed STIHL Autocut 25 2 26 Storing the Machine 51 cutting tool some special safety pre STIHL Autocut 30 2 26 Mai...

Page 3: ...e handle 6 Throttle cable retainer 7 Carrying loop 8 Throttle cable stop switch wire 9 Spark plug terminal 10 Air filter cover 11 Choke lever 12 Machine support 13 Fuel tank 14 Fuel filler cap 15 Starter grip 16 Carburetor adjusting screws 17 Muffler 18 Deflector for all cutting tools without skirt 19 Metal cutting Itool cutting blade 230 ...

Page 4: ...ung backwards toward the operator during starting and switches the 11 Choke lever by the cutting tool and from contact engine s ignition off and stops the Eases engine starting with the cutting tool engine by enriching mixture 19 Cutting tool 4 Throttle trigger interlock 12 Machine support The cutting attachment i e blade Must be depressed before the For resting machine on the ground made from met...

Page 5: ... control 5 Throttle trigger 6 Throttle trigger interlock 7 Throttle cable stop switch wire 8 Spark plug terminal 9 Air filter cover 10 Choke lever 11 Machine support 4 19 17 18 12 Fuel tank 13 Fuel filler cap 14 Starter grip 15 Carburetor adjusting screws 16 Muffler 17 Deflector for mowing heads 18 Line limiting blade 19 Cutting tool ...

Page 6: ...he harness For resting machine on the ground 18 Line limiting blade Metal blade at the deflector in order to keep the line of the mowing head 4 Slide control 12 Fuel tank at the proper length Starting throttle lock and stop switch For fuel and oil mixture Keeps the throttle partially open during starting and switches the 19 Cutting tool engine s ignition off and stops the 13 Fuel filler cap The cu...

Page 7: ...ders or the operator Striking such objects could damage the cutting attachment and may cause blades to crack chip or break STIHL does not recommend the use of rigid blades when cutting in stony areas Thrown objects or damaged blades may result in serious or fatal injury to the operator or bystanders 6 Warning Minors should never be allowed to use a brushcutter Bystanders especially children and an...

Page 8: ...shcutter may not protect the operator from all foreign objects gravel glass wire etc thrown by the wheeling cutting attach ment Thrown objects may also ricochet and strike the operator Therefore to re duce the risk of injury to your eyes never operate a brushcutter unless wearing goggles or properly fitted safety glasses with adequate top and side protection complying with ANSI Z 87 1 or your app ...

Page 9: ...nd grip to suit your size before starting work The machine should be properly balanced as specified in your owner s manual for proper control and less fatique in operation Always check your bruhcutter for proper condition and operation before starting particularly the throttle trigger throttle trigger interlock if applicable stop switch cutting tool deflector and harness Arrows on the deflector A ...

Page 10: ...ire tighten fuel cap by hand with as much force as possible The screw driver end of the STIHL combination wrench or other similar tool can be used as an aid in tightening slotted fuel caps Starting Warning Your brushcutter is a oneperson machi ne Once started it may fling foreign ob jekts for a great distance To reduce the risk of eye and other injury insure that bystanders are at least 50 feet 15...

Page 11: ...times Make sure your brush cutter handles and grip are in good con dition and free of moisture pitch oil or grease 10 Warningl Never attempt to operate any brush cutter with one hand Loss of control of the brushcutter resulting in serious or fatal injury may result To reduce the risk of bodily injury resulting from loss of control and contact with the cutting tool make sure your unif is equipped w...

Page 12: ...y Such tools may shatter at high speed and cause serious or fatal injury Warn ng A loose blade may cause the blade to vibrate crack break or come off the brushcutter which may result in serious or fatal injury Make sure that the blade is properly tightened Use the wrench supplied or one of sufficient length to obtain the proper torque If the blade loosens after being properly tightened stop work i...

Page 13: ... operations described in your manual With the engine running attach the brushcutter to the spring hook of your harness see appropriate chapter of this manual USING THE CUTTING TOOLS For an illustration of the various cutting tools and instructions on proper mount ing see the chapter on mounting the cutting tools in your owner s manual Using the mowing heads The STIHL Supercut Autocut Polymatic and...

Page 14: ...1 111111 1 _ 1l11l 1 dlll l I 111 111 11 I 11 1111 111111 II 111111111 II I It I tll _ 11111 1111111 I 11111 I 11111 11111 illllll llili 11 11111111111 ViI II i1II1 11 JIII l llllillil 1111 1111 dol 11l1 111l l i lIl II Illillllll 1 1111111111 1 0 II 11111l1 111 11 11 11111 118 when it has worn as far as one of these marks It is important to follow the maintance instructions supplied with the head...

Page 15: ...y it is essential to take the following precautions Avoid contact with hard or solid foreign objects such as stones rocks or pieces of metal Never cut wood or shrubs with a stem diameter of more than 2cm 3 4 use a circular saw blade for such work Inspect the brush knife at regular short intervals for signs of damage Do not continue working with a damaged brush knife Resharpen the brush knife re gU...

Page 16: ...he cutting tool be sure to remount the standard deflector for all other u ses N o en o o o positioned against the tree during the cutting process Inexperienced users should place the left side of the stop against the tree trunk before beginning to cut This act will keep the brush cutter against the tree during the cutting operation and will reduce the risk of loss of control and possible kickout d...

Page 17: ...rigid blade and never use a rigid blade on a brushcutter with a loop handle MAINTENANCE REPAIR AND STORING Use only identical STIHL replacement parts for maintenance and repair Use of parts manufactured by others may cause serious or fatal injury Follow the maintenance and repair instructions in the appropriate section of your owner s manual Please refer to the maintenance chart at the last pages ...

Page 18: ...ged missing or mode fied An improperly maintained muffler will increase the risk of fire and hearing loss Never touch a hot muffler or burn will result If your muffler was equipped with a spark arresting screen to reduce the risk of fire e g in the USA Canada and Australia never operate your hedge trimmer if the screen is missing or dama ged Remember that the risk of forest fi res is greater in ho...

Page 19: ...ever 23 Bike handle 18 Carrying straps 24 Shoulder strap recommended 25 Shoulder strap 26 Full harness recommended 27 Full harness A fully equipped brushcutter comprises among other items Cutting tool Deflector Handle Carrying strap Select the correct combination from the table according to the cutting tool you intend to use For safety reasons you may only combi ne the cutting tool deflector handl...

Page 20: ...Cutting tools Deflectors Handles Carrying straps 2 0 20 15 3 4 21 5 6 22 24 16 7 8 23 V l t J e C 9 25 10 11 21 1 18 J 22 12 23 V A I 25 26 19 13 14 23 V 0 27 19 ...

Page 21: ...as stop Line up the bike handle Tighten the screws firmly Fitting the control handle Remove the screw 6 from the nut 7 Take both parts out of the control handle 8 Push the control handle onto the bike handle 5 throttle trigger 9 must point in direction of gear head Line up the holes 10 Fit nut and screw in the control handle Tighten the screw firmly Fitting the throttle cable Do not kink the throt...

Page 22: ... lQj I fIlII 41 3 3 Insert square nuts 3 in the standoff lever 4 line up the holes 4 On FS 108 Place the clamp 5 in the loop handle 1 and position them both against the drive tube 6 Fit the clamp 7 and place standoff lever 4 in position line up the holes Ir selfscrews 8 in holes and screw them into standoff lever fingertight Align the loop handle Tighten the screws firmly 21 ...

Page 23: ...ngertight Align the loop handle Tighten the screws firmly 22 Mounting the Loop Handle Version A At A 1 o o Mount the loop handle 1 20 cm 8 A forward of the control handle 2 On FS 108 Place the clamp 3 in the loop handle 1 and position them both against the drive tube 4 Fit the clamp 5 line up the holes Insert screws 6 in holes and screw on the nuts 7 fingertight Align the loop handle Lock the nuts...

Page 24: ...e Lock the nuts and tighten the screws firmly Mounting the Loop Handle Version B Mount the loop handle 1 20 cm 8 A forward of the control handle 2 Place the clamp 3 in the loop handle 1 On FS 88 Place packing sleeve 5 on the drive tube 4 On FS 108 Place both parts on the drive tube 4 Fit the clamp 6 and make sure that the holes line up Insert the screws 7 as far as stop Line up the loop handle and...

Page 25: ...own securely 24 Fitting skirt and blade Slide the lower guide slot of the skirt 4 over the deflector 1 it must snap into position Push blade 5 into the upper gUide on the skirt and line it up with the first hole Fit the screw and tighten it down firmly Fitting stop for circular saw blades Remove standard deflector Place the stop 1 on the gear head flange fit the three M 5 x 18 screws 2 provided an...

Page 26: ... as far as stop apply slight pressure Rotate output shaft until the stop pin slips into position and blocks the shaft Removing cutting tool mounting hardware Position combination wrench 3 on the mounting nut 4 Release and unscrew the nut clockwise left hand thread Remove shipping keeper 5 if fitted Pull the rider plate 6 and thrust washer 7 off the shaft 8 Now fit the cutting tool 25 ...

Page 27: ... line is advanced auto matically providing at least 6cm 2 4 of line is still projecting from the head Blade on deflector trims surplus line to correct length Fit new nylon line as described in instructions supplied with mowing head STIHL Autocut 25 2 STIHL Autocut 30 2 Lay your brushcutter on its back with the gear head facing up Screw mowing head counterclock wise onto the output shaft 1 as far a...

Page 28: ...c 2 1 3 4 c I STIHL Autocut 24 2 STIHL Polymatic 30 2 Lay your brushcutter on its back with the gear head facing up Slip the plain washer 1 and thrust washer 2 over the shaft 3 and against the thrust plate 4 Screw mowing head counterclock wise onto the output shaft as far as it will go Block the output shaft Tighten down the mowing head securely Important Remove the stop pin Keep instruction sheet...

Page 29: ...haft and unscrew the mounting nut clockwise If the mounting nut becomes slack due to frequent loosening and retightening fit a new one Replacing cutting blades Refer to instruction sheet supplied with fixed line head Lay your brushcutter on its back with the gear head facing up Place mowing head on the thrust plate 1 Slip the thrust washer 2 over the output shaft 3 Block the output shaft Screw mou...

Page 30: ...tter on its back with the gear head facing up Place cutting tool 1 on the thrust plate 2 Cutting edges of blade 230 8 3 must point clockwise Cutting blade 230 4 4 and brush knife 5 may be fitted either way round Slip the thrust washer 6 and rider plate 7 over the output shaft 8 Block the output shaft Screw mounting nut 9 counter clockwise on to output shaft and tighten down securely Important Remo...

Page 31: ... gear head facing up Position saw blade 3 on the thrust plate 4 teeth must point in clockwise direction Slip the thrust washer 5 and rider plate 6 over the drive shaft 7 Block the drive shaft Screw mounting nut 8 counterclockwise on to drive shaft and tighten down securely Releasing mounting nut Block the drive shaft and unscrew the mounting nut clockwise If the mounting nut becomes slack due to f...

Page 32: ...the classification TC for mixing We recommend STIHL 50 1 two stroke engine oil since it is specially formulated for use in STIHl engines The mix ratio with STIHl oil is 50 1 50 parts gasoline to 1 part oil or 25 1 25 parts gasoline to 1 part oil with other branded two stroke air cooled engine oils Do not use BIA or TCW two stroke water cooled mix oils Take care when handling gasoline Avoid direct ...

Page 33: ... a loop handle come without a harness available as special acces sory for these models Shoulder strap Use of the carrying strap is described in chapters Safety Precautions and Selecting the Cutting Tool Warning In order to reduce the risk of bums or other personal injury from esca ping gas vapor and fumes remove the fuel filler cap carefully so as to allow any pressure build up in the tank to rele...

Page 34: ...lancing the brushcutter Attach the spring hook 3 to the clamp 4 on the drive shaft slacken the screw 5 Slide the clamp up or down the drive shaft Tighten the screw moderately Let go of the brushcutter and check to see how it is balanced mowing heads Fixed Line Head and brush knife must rest lightly on the ground Circular saw blades must stay abottt 30cm 1 ft A clear of the ground Tighten the screw...

Page 35: ...throttle position 34 If engine is cold Set the choke lever 4 to L If engine is warm Set the choke lever 4 to Also use this setting il engine has been running but is still cold Put the unit on the ground It must rest securely on the engine support and deflector Check that the cutting tool is not touching the ground or any other obstacles Make sure you have a firm looting Hold the unit with you left...

Page 36: ...rter rope can rewind properly When engine begins to fire If engine is cold Set choke lever 4 to and continue cranking until engine runs If engine is warm Continue cranking until engine runs_ As soon as warm engine runs Blip the throttle trigger 2 the slide control 3 moves to the run position I and the engine returns to idling speed Make ure carburetor is correctly adj usted cutting tool must not r...

Page 37: ...lever to L quickly enough after the engine began to fire the combustion chamber is flooded Remove spark plug terminal 5 Unscrew and dry off the spark plug Set slide control to STOP Open the throttle fully Pull the starter rope several times to clear the combustion chamber Refit the spark plug and connect the spark plug terminal Set slide control to START Set choke lever to even if engine is cold N...

Page 38: ...e following adjustments H Open 1 full turn L Open 1 full tum Start the engine and adjust idling speed with the idle speed adjusting screw LA or LD cutting tool must not rotate This standard setting is the optimum setting of the high speed adjusting screw for normal operation at an altitude of about 300 m 1000 It above sea level It ensures your machine will deliver maximum power be fuel efficient a...

Page 39: ...kwise until you hear 38 no further increase in RPM back off screw one eighth turn Machines with metal cutting tool A tachometer is necessary for the following adjustment If no tachometer is available do not turn screws beyond the basic setting Carry out the basic setting Warm up engine by running it for about 1 minute at full throttle and then return to idle speed Back off high speed adjusting scr...

Page 40: ...l must not rotate Cutting tool rotates when engine is idling Turn the idle speed adjusting screw LA or LD counterclockwise until cutting tool stops rotating then back off screw about another one half tum from that position Erratic idling behavior poor acceleration Idle setting is too lean Turn the low speed adjusting screw L counterclockwise until engine runs and accelerates smoothly Exhaust smoke...

Page 41: ...k fillings 40 During operation After long period of full throttle operation allow engine to run for a while at idling speed so that the heat in the engine can be dissipated by flow of cooling air This protects engine mounted components ignition carburetor from thermal overload After finishing work Storing for short period To avoid condensation fill the fuel tank and keep the unit in a dry place un...

Page 42: ... only suppressed spark plugs of the approved type Rectify faults which have caused fouling of spark plug Incorrect carburetor setting too much oil in fuel mix dirty air filter unfavorable running conditions e g operating at part load Fit a new spark plug after approx 100 operating hours or earlier if the electrodes are badly eroded If there is a noticeable loss of engine power Set choke lever to L...

Page 43: ... the gear head on e g warm soapy water and then de of the filler plug screw the tube the drive tube dry 2 of STIHL gear lubricant Release the clamp screws 1 0781 120 1117 into the filler hole Pull the gear head 2 off the Replace damaged parts of filter Squeeze grease into the gear drive tube housing about 5 10 g 1 4 oz Place the felt element in the filter base 5 first and then Do not completely fi...

Page 44: ...ube into the gear head turn drive shaft 4 back and forth until mark is reached Line up the gear head Tighten down the clamp screws If shaft has turned blue fit a new one Pull the shaft 3 out of the drive tube Use STIHL multipurpose grease 0781 120 1109 to coat dry areas of the shaft Do not apply too much grease never pump grease into the drive tube t 3 0 J r To avoid out at balance Resharpen the c...

Page 45: ...t might shatter and cause serious or fatal injury Resharpen when the tips of the cutting edges 1 have worn down to about 1mm 3 64 A To avoid out of balance Resharpen the cutters 2 uniformly do not alter the contour of the parent blade 3 in any way After resharpening about 5 times have blade checked on STIHL balancer 5910 850 2600 and rebalanced as necessary Measurements and angles for resharpening...

Page 46: ...e file are usually enough Brush knite 250 Never straighten or weld a bent or cracked brush knife it might shatter and cause serious or fatal injury Only sharpen the cutting edges 1 at the pointed tips do not sharpen curved cutting edges 2 even if theyare nicked in places To avoid out at balance Resharpen cutting edges uniformly use the sharpening template 0457 342 2629 provided After resharpening ...

Page 47: ... 200 chisel tooth Never straighten or weld a bent or cracked circular saw blade it might shatter and cause serious or fatal injury Sharpening circular saw blade on the unit Cut a vertical slit in the top of a tree stump lean the unit against the stump so that the saw blade rests in the slil Turn the blade with one hand while resharpening Wear gloves Sharpen correctly File only the side plate 1 If ...

Page 48: ...e is a gap C between the tooth and saw set see Resetting the teeth If the tooth just touches the saw set Clearance 0 is 1mm 3 64 and the set is correct Resetting correctly the teeth Fit notch of saw set 4 over the tooth 6 blade thickness 1 5mm about 1 16 Maintain the angle of 90 E and keep to existing direction of set Push the saw set downward until the sloRing side F of the notch butts against th...

Page 49: ...ible two or three strokes of the file are usually enough Do not alter tooth profile Removing rewind starter Lay your brushculler on its back with the gear head facing up Remove the four screws 1 from the machine support 2 and lift it away Take out the screws 3 Remove the starter cover 4 together with rewind starter mechanism Replacing a broken starter rope Take out the screw 5 Remove the washer 6 ...

Page 50: ...inous oil Slide rotor onto starter post turn it back and forth until anchor loop 8 of rewind spring engages Fit screw and washer and tighten down firmly Go to Tensioning rewind spring a 2mm O 08in Replacing a broken rewind spring Lubricate the new spring with a few drops of non resinous oil do not open the wire retainer Remove the rope rotor as described in Replacing a broken starter rope Rei tlov...

Page 51: ...ll revolutions counterclockwise Hold the rotor steady straighten the twisted rope release the rotor Let go of rope slowly so that it winds onto the rotor The starter grip must be firmly seated in the rope guide bush If grip droops to one side Add one more turn on rope rotor to increase spring tension When starter rope is fully extended it must be possible to rotate the rotor another half turn If t...

Page 52: ...rk arresting screen if necessary If screen is damaged or coked up fit a new one Refit the spark arresting screen Fit the cover Fit the shroud For periods of about 3 months or longer Drain and clean the fuel tank Run engine until carburetor is dry this helps prevent the carburetor diaphragms sticking together Remove clean and inspect the ClLtting tool Thoroughly clean the machine pay special attent...

Page 53: ...operation x x 34 36 Air filter Clean x x 41 42 Replace x 41 42 r Check 32 Filter in fuel tank x Replace x 32 Fuel tank Clean I x 31 Check idle adjustment Carburetor cutting tool must not turn x x 37 39 Readjust idle x 37 39 Spark plug Readjust electrode gap x 41 Cylinder fins Clean x Spark arresting screen in muffler Inspect x I 51 Clean or replace x x 51 All accessible screws and nuts not adjusti...

Page 54: ...34 in 1 46 in Stroke 28 mm 32 mm 1 10 in 1 26 in Engine power 0 9 kW 1 1 kW to ISO 8893 1 2 bhp 1 5 bhp Max permissible engine speed with metal cutting tool rpm 12 000 12 000 Max output shaft speed tool moun ting rpm 8800 9000 Idle speed rpm 2800 2 800 Ignition System Fuel System Carburetor All position diaphragm carburetor with integral fuel pump Air filter Foam and felt elements Fuel tank capaci...

Page 55: ...ool 95 103 2 7 2 4 5 0 6 3 FS 88 R 3 Mowina head 98 109 2 5 2 0 6 3 6 3 FS 88 R 4 Metal tool 95 103 2 5 2 0 9 4 6 7 FS 108 2 Mowina head 99 111 2 4 3 7 2 4 2 8 FS 108 2 Metal tool 96 105 2 4 3 7 2 1 2 5 FS 108 R 3 Mowina head 99 111 1 8 1 8 4 4 5 4 FS 108 R 4 Metal tool 96 105 1 8 2 2 4 4 3 5 1 2 3 4 54 Weighted equivalent level includes idling and maximum RPM with the same duration of exposure Ve...

Page 56: ...224 5 STIHL Autocut 30 2 4002 710 2107 Thermoplastic blades 6 STIHL Polymatic 30 2 for 8 4002 710 2120 Pack of 12 41110071001 7 STIHL Fixed Line Head 40017132100 Transport guards for 9 to 11 4119 790 3906 8 STIHL Polycut 40 3 for 12 and 13 4119 790 3901 4111 7102100 9 Grass cutting blade 230 4 Other special accessories 4001 7133801 Shoulder strap Full b mess 10 Grass cut1ing blade 230 8 Goggres 40...

Page 57: ... WARNING The engine exhaust from this product contains chemicals known to the State of California to cause cancer birth defects or other reproductive harm englisch english U S A ...

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