14.8.2 Removing and Installing 14.8.3 Manual Fuel Pump 14.9 Fuel Intake 14.9.1 Pickup Body 14.9.2 Fuel Intake Hoses 14.9.3 Fuel Hoses, Tank Vent / Manual Fuel Pump 14.9.4 Fuel Tank Cap Special Servicing Tools Servicing Aids MS 171, MS 181, MS 211...
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4.2 = Reference to another chapter, i.e. chapter 4.2 in this example Service manuals and technical information bulletins are intended exclusively for the use of properly equipped repair shops. They must not be passed to third parties. MS 171, MS 181, MS 211...
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This symbol may appear alone on engine. small parts. Storing and disposing of oils and fuels Collect fuel or lubricating oil in a clean container and dispose of it properly in accordance with local environmental regulations. MS 171, MS 181, MS 211...
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Air gap between ignition module and 0.15...0.35 mm fanwheel: Spark plug (suppressed): NGK CMR 6H Electrode gap: 0.5 mm Chain Lubrication Fully automatic, speed-controlled oil pump with reciprocating piston Oil delivery rate: 7.0 cm³/min at 10,000 rpm MS 171, MS 181, MS 211...
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M 12x1 L Clutch/crankshaft 50.0 Screw D 5.3x41 Crankcase/engine pan/cylinder 11.0 Collar nut Baffle/filter base/collar screw, carburetor Screw D 5x18 Muffler/cylinder M 8x1 Flywheel/crankshaft 28.0 M 10x1 Spark plug 12.0 Screw D 4x18 Ignition module/cylinder MS 171, MS 181, MS 211...
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Power screwdriver setting for polymer: DG and P screws max. 500 rpm Do not use a impact wrench for releasing or tightening screws. Do not mix up screws with and without binding head MS 171, MS 181, MS 211...
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Loud noises Clutch springs stretched or fatigued Replace all clutch springs Needle cage damaged Fit new needle cage Clutch shoe retainer broken Fit new retainer Clutch shoes and carrier worn Install new clutch MS 171, MS 181, MS 211...
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Saw chain does not stop Brake spring stretched or broken Fit new brake spring immediately when brake is activated Brake band stretched or worn Fit new brake band Clutch drum worn Fit new clutch drum MS 171, MS 181, MS 211...
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Oil intake hose not properly fitted or Fit oil intake hose properly or install damaged new hose Unsuitable chain lubricant has been Drain unsuitable chain lubricant used from oil tank and fill up with recommended chain lubricant MS 171, MS 181, MS 211...
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Coat rewind spring with a little becomes viscous at very low standard solvent-based degreasant outside temperatures (spring (containing no chlorinated or windings stick together) halogenated hydrocarbons), then pull rope carefully several times until normal action is restored MS 171, MS 181, MS 211...
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Check operation of spark plug, clean spark plug and replace if necessary. A problem with the carburetor or the engine can also be the reason for erratic running behavior. MS 171, MS 181, MS 211...
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Faulty insulation or short in short Check short circuit wire for short circuit wire circuit to ground Break in ignition lead or insulation Check ignition lead, replace ignition damaged module if necessary Ignition module faulty Install new ignition module MS 171, MS 181, MS 211...
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Inlet needle sticking to valve seat Remove inlet needle, clean and refit Diaphragm gasket leaking Fit new diaphragm gasket Metering diaphragm damaged or Fit new metering diaphragm shrunk Manifold damaged Install new manifold MS 171, MS 181, MS 211...
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Idle jet bores or ports blocked Clean the carburetor Idle jet too rich or too lean Set low speed screw (L) correctly Setting of idle speed (LA) Set idle speed screw (LA) incorrect – throttle shutter correctly completely closed MS 171, MS 181, MS 211...
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Check lever on air valve and and low maximum speed throttle position replace if necessary Erratic idle – too lean Air valve does not close properly Check lever on air valve and replace if necessary MS 171, MS 181, MS 211...
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Check air valve and replace if necessary Engine overheating Insufficient cylinder cooling. Air Thoroughly clean all cooling air inlets in fan housing blocked or openings and the cylinder fins cooling fins on cylinder very dirty MS 171, MS 181, MS 211...
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(2) and tensioning gear (3) with reverse sequence. guide bar (4). – Install in the reverse sequence. – Tightening torques, b 3.5 : Remove the screw (arrow). – Remove the cover plate (1) and adjusting wheel (2). MS 171, MS 181, MS 211...
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: Unscrew the spark plug (1). Disassembling : Slip the retainers (1) onto the clutch shoes. – Clamp the clutch in a vise. : Use hook (2) 5910 890 2800 to remove the clutch springs (1). MS 171, MS 181, MS 211...
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(arrow) faces outwards. : Use the hook (2) 5910 890 2800 to attach the other ends of the springs and press them firmly into the clutch shoes – do not overstretch the springs. MS 171, MS 181, MS 211...
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Remove and install the clutch drum drum (1), check the remaining wall (1), see instruction manual. thickness. If it is less than about 80% of the original thickness, install a new clutch drum. MS 171, MS 181, MS 211...
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(arrow). : Use a screwdriver to ease the cover (1) away at the points shown (arrows). – Remove and inspect the cover (1), service or replace if necessary. MS 171, MS 181, MS 211...
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(arrows) and push it fully – Install the clutch drum, home. b 6.1 – Reassemble all other parts in the reverse sequence. : Swing the brake band into the guide (arrow) first. – Check operation. MS 171, MS 181, MS 211...
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: Pull the hand guard (1) and brake the holes. lever (2) off the pivot pins – To ease assembly, remove the (arrows) together. rewind starter, b 10.2 – Remove the hand guard and brake lever. MS 171, MS 181, MS 211...
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: Ease the cam (arrow) of the hand guard (2) past the flat spring (1). – Push the hand guard and brake lever onto the pivot pins, moving the hand guard to and fro at the same time. MS 171, MS 181, MS 211...
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Loctite, b 16 : Position the new pin (1) in the bore (arrow) so that the knurling on the pin meshes with the existing knurling in the bore. Turn pin back and forth as necessary. MS 171, MS 181, MS 211...
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– Install in the reverse sequence. – Fit the collar studs and tighten : Remove the screw (arrow). them down firmly. – Tightening torques, b 3.5 – Reassemble all other parts in the reverse sequence. MS 171, MS 181, MS 211...
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– Remove the muffler (1), check and replace if necessary. : Inspect and clean the sealing faces (arrows), b 16 : Push home the plugs (arrows). – Position machine vertically. – Tightening torques, b 3.5 MS 171, MS 181, MS 211...
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: Fit the sealing plate (1) 0000 855 8106 between the : Fit the nuts (arrows) and tighten cylinder exhaust port and flange – Tightening torques, b 3.5 them down firmly. and tighten down the screws moderately. MS 171, MS 181, MS 211...
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– Tighten down the muffler firmly. : Operate the lever (2) until the – Reassemble all other parts in the pressure gauge (arrow) indicates reverse sequence. a vacuum of 0.5 bar. – Tightening torques, b 3.5 MS 171, MS 181, MS 211...
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– Degrease the crankshaft taper, b 16 : Apply puller (1) 5910 890 4400 with No. 3.1 jaws 0000 893 3706. – Reassemble all other parts in the reverse sequence. MS 171, MS 181, MS 211...
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– Apply thin coating of sealant, b 16, to the outside diameter of the oil seal. : Lift the shroud (1) a little and pull it off in the direction of the rear handle. MS 171, MS 181, MS 211...
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– If necessary, also remove the The carburetor carrier can be also (1) into the guides (arrows) until carburetor carrier, b 14.7.1 be removed after the engine has they snap into position. been removed. MS 171, MS 181, MS 211...
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– support engine pan from below : Pry the engine pan (1) away from with one hand. the engine at the lugs (arrows). – Remove the engine pan. : Pull the oil seals (arrows) off the crankshaft stub. MS 171, MS 181, MS 211...
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If a new cylinder is installed, transfer long crankshaft stub (1) must be on the intake manifold (if it is still the right. serviceable) from the old cylinder. : Fit the retaining ring (1). MS 171, MS 181, MS 211...
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Take care not to damage the bearings and oil seals in the crankshaft stubs. bearing seats in the cylinder, making sure the oil seals are properly seated (arrows) in the housing. MS 171, MS 181, MS 211...
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: Use a suitable tool to ease the hookless snap rings out of the : Remove the piston (1) from the grooves in the piston bosses connecting rod. (arrow). – Inspect the piston rings and replace if necessary, b 8.8.1 MS 171, MS 181, MS 211...
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The inner pin (2) must point towards the flat face (3) of tool's shank. : Fit the piston pin (2) on the assembly drift (1) and slide it into the piston. MS 171, MS 181, MS 211...
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: Position the piston rings so that – Remove the piston rings from the the radii at the ring gap meet at piston – the MS 171 has only one the fixing pin in the piston groove piston ring. (arrows).
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: Pull off the spark plug boot (1). The ignition module accommodates all the components required to : Remove the ignition module (1). control ignition timing. There are two electrical connections on the coil body: MS 171, MS 181, MS 211...
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9.4 – Troubleshooting, b 4.5 : Fit the wire terminal (1) so that it is against the stop (arrow) and insert the screw – do not tighten down yet. : Fit the retainer (1). MS 171, MS 181, MS 211...
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: Fit the short circuit wire (1) in the retainer (arrow) and reconnect it. Short circuit and ground wires must be next to one another in the retainer – ground wire must face the cylinder. MS 171, MS 181, MS 211...
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(2), ground : Hold the ignition lead and leg – Pull the boot off the ignition lead. connection (5) and the ground spring together and push them terminal (1). into the spark plug boot. MS 171, MS 181, MS 211...
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– Remove the shroud, b 8.4 – Tightening torques, b 3.5 – Block the piston with the locking strip (1), b 6 – Unscrew the puller and remove the flywheel. MS 171, MS 181, MS 211...
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9.7 – Check ground wire for continuity. : Take out the screw and remove the ground wire (2). – Install in the reverse sequence. MS 171, MS 181, MS 211...
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: Push short circuit wire connector tie on the wiring harness. (1) into receptacle on switch shaft (arrow) as far as stop. : Position the ground wire (1) against the protective rib (arrow) – to avoid unintentional disconnection. MS 171, MS 181, MS 211...
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9.1.1 : Push the contact spring (1) into – Reassemble all other parts in the reverse sequence. its seat until the lug (arrow) snaps into position. – Tightening torques, b 3.5 MS 171, MS 181, MS 211...
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9.6.2 – Reassemble all other parts in the reverse sequence. – Tightening torques, b 3.5 : Position the ground wire (1) against the protective rib (arrow) – to avoid unintentional disconnection MS 171, MS 181, MS 211...
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– If necessary, install new spark plug boot and/or leg spring, b 9.4 Test ignition system: with ZAT 3 or ZAT 4 (use ZAT 3 as main spark gap – see TI 32.94), b 9.3 MS 171, MS 181, MS 211...
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– Severe chafing? – Spark plug boot: Holes/cracks? – Resistance: spark plug boot to ground: spec. 1.5 – 12 kΩ If necessary, install new spark plug boot and/or ignition lead with ignition module, b 9.4 MS 171, MS 181, MS 211...
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9.1.1 Engine runs Machine runs trouble-free, –Look for fault in fuel system no further action necessary or carburetor – Check engine for leaks – Check position of flywheel on crankshaft, b 8.2, b 9.5 MS 171, MS 181, MS 211...
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(1) and washer. Machines with ErgoStart – Tightening torques, b 3.5 – Relieve tension of spring, b 10.4 : Push the locking tab (arrow) to one side and take out the segment (1). MS 171, MS 181, MS 211...
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Check that washer (3) is in place. : Position the spring clip (1) so that its loop engages the peg on the pawl and its curved part (arrow) is in the starter post’s groove. MS 171, MS 181, MS 211...
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(arrow). : Remove the E-clips (arrows). – Install the E-clips. – Pull off the pawls (1) and remove the torsion springs. – Clean the pawls (1), b 16 MS 171, MS 181, MS 211...
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: Push the end of the starter rope – Install the pawl(s) and spring clip, (1) out a little and undo the knot. b 10.3 – Pull the starter rope out of the rope rotor and fan housing. MS 171, MS 181, MS 211...
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: Pull the starter rope through the grip until the knot is seated in the Do not shorten the starter rope. recess (arrow). : Thread the starter rope (1) through the guide bushing (arrow). MS 171, MS 181, MS 211...
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– Hold the rope rotor (2) steady. rope. : Pull out the twisted rope (1) with – Install the fan housing and, if the starter grip and straighten it necessary, the segment, b 10.1 out. and b 10.2 MS 171, MS 181, MS 211...
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(1). Line up the installing tool so that the anchor loop (2) is above the lug (3) and the opening in the installing tool is in the position shown (arrow). MS 171, MS 181, MS 211...
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The open side of the anchor loop clockwise until the spring is (arrow) must face inwards. Then fit properly seated. the rewind spring (1) counter- clockwise. – Remove the installing tool. MS 171, MS 181, MS 211...
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: Screw the anti-vibration spring (2) into the handle frame (arrow) as far as stop. – Remove the shroud, b 8.4 : Remove the screw (arrow). – Lower the handle frame (1) a little. MS 171, MS 181, MS 211...
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(2) and retainer (3) and little. replace if necessary. – Reassemble all other parts in the : Remove the screw (arrow). reverse sequence. – Take out the anti-vibration spring. – Tightening torques, b 3.5 MS 171, MS 181, MS 211...
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– Pry the anti-vibration springs out of their mounts. : Pull tank vent hose (1) off the nipple. – Hold the rear handle, turn the handle frame to the right and take it out. MS 171, MS 181, MS 211...
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– Reassemble all other parts in the reverse sequence. – Tightening torques, b 3.5 : Insert and firmly tighten down the screws (arrows) of the anti- vibration springs on the oil tank and cylinder. MS 171, MS 181, MS 211...
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(2). – Remove the switch shaft and lever. : Apply screwdriver to edge – Inspect the switch shaft and lever (arrow) and pry the lever (1) out and replace if necessary. of its seat. MS 171, MS 181, MS 211...
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: Push the lever (1) into the mounts until it snaps into position. : Line up the switch shaft (1) and push it into the right-hand mount (arrow). – Position the switch shaft and lever against the mounts. MS 171, MS 181, MS 211...
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– Remove the filter base, b 14.2 : Use a screwdriver to ease the : Place throttle trigger (1) in lugs (arrows) apart and push mounts (arrow) in rear handle. them through the handle frame from below. MS 171, MS 181, MS 211...
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(3) and push it into mount. the guides (arrows) until it snaps into position. : Depress the interlock lever until its stop (1) engages – this is the position required for mounting the handle molding. MS 171, MS 181, MS 211...
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– Install in the reverse sequence. : Pry the oil suction hose (1) off the oil tank connector (arrow). – Pull out the oil suction hose with pickup body, inspect it and replace if necessary. MS 171, MS 181, MS 211...
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– Remove the handle frame, b 11.4 : Line up the oil pump (1) as shown by the symbol (arrow) – the countersunk bore must line up with the cross bore in the oil pump’s seat. MS 171, MS 181, MS 211...
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: Remove the old valve (1) from b 8.3 the oil tank. – Install the handle frame, b 11.4 – Reassemble all other parts in the reverse sequence. – Tightening torques, b 3.5 MS 171, MS 181, MS 211...
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: Use a 6 mm drift to carefully drive in the new valve from outside – note installed depth. : Installed depth of valve: a = about 2.5 mm – Reassemble all other parts in the reverse sequence. MS 171, MS 181, MS 211...
(arrows). if necessary. difficult. – Remove and inspect the baffle – Coat O-ring (2) with STIHL Press The air filter should be checked (1) and replace if necessary. Fluid before installing, b 16 when there is a noticeable loss of engine power.
– Reassemble all other parts in the reverse sequence. – Disconnect the choke rod, b 14.6 – Tightening torques, b 3.5 – Set Master Control lever to “ “ Sleeve (1) must be in place. MS 171, MS 181, MS 211...
(arrow). off the carburetor. – Install the carburetor, b 14.3 – Reassemble all other parts in the reverse sequence. – Tightening torques, b 3.5 MS 171, MS 181, MS 211...
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(2) and reverse sequence. carburetor body (arrows). gasket (1). – Tightening torques, b 3.5 : Position the gasket (1) and metering diaphragm (2) so that the tabs (arrows) with holes point towards the adjusting screws. MS 171, MS 181, MS 211...
: Position the inlet control lever (3) with spindle (2) on the spring’s seat (arrow) first, then slide the : Remove the inlet needle (1). inlet control lever’s clevis into the groove in the inlet needle (1). MS 171, MS 181, MS 211...
16 : Remove the screw (arrow). : Position the valve jet (1) so that the centering taper (arrow) points towards the carburetor bore. MS 171, MS 181, MS 211...
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: Use a needle to remove the fuel strainer (1) from the carburetor body. – Install in the reverse sequence. – Line up the end cover (1) so that the shoulder (arrow) points towards the throttle shutter. MS 171, MS 181, MS 211...
: Remove the E-clip (arrow). – Pull out the air valve shaft (1) and disconnect and relax the torsion spring (2) at the same time. – Clean the air valve shaft and guides, b 16 MS 171, MS 181, MS 211...
: Slide the air valve (1), with the hole (2) on the left and the marking visible, into the slot in the shaft. : Position leg of torsion spring against web (arrow) on valve body. MS 171, MS 181, MS 211...
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: Position the torsion spring (2) on the throttle shaft (arrow). : Remove the E-clip (arrow). – Pull out the choke shaft (1) in the direction of the lever. Disconnect and relax the torsion spring at the same time. MS 171, MS 181, MS 211...
– Close the choke shutter (2) and center it in the carburetor body’s bore. – Tighten down the screw firmly. : Remove the screw (arrow). – Check freedom of movement. – Reassemble all other parts in the reverse sequence. MS 171, MS 181, MS 211...
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(2) on the left, on the flat side of bore (arrow) and then push the the shaft – the marking must be throttle shaft all the way through. visible. MS 171, MS 181, MS 211...
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(arrow) first, onto the throttle shaft. : Turn the lever (1) clockwise until its arm can be fitted against the stop (arrows) and the lever (1) engages the two flats on the throttle shaft. MS 171, MS 181, MS 211...
L as far as stop. L = low speed screw (2) LA = idle speed screw (3) – Continue with high speed screw If the carburetor cannot be adjusted properly, the problem may be the adjusting screws. MS 171, MS 181, MS 211...
Always install a new limiter cap. First position it so that its lug is below the stop (arrow) and then press it onto the high speed screw. : Press the limiter cap (1) onto the high speed screw H. MS 171, MS 181, MS 211...
– Turn the high speed screw H – Turn the low speed screw L clockwise (leaner) – no further slowly clockwise as far as stop, than stop. then turn it back 1 full turn MS 171, MS 181, MS 211...
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– Remove the throttle rod. Check it and replace if necessary. – Reassemble all other parts in the reverse sequence. : Pass the throttle rod (1) under the throttle trigger (2) and push it into the hole (arrow). MS 171, MS 181, MS 211...
: Inspect and clean the sealing face (arrow) on the cylinder, b 16 The sealing face must be perfectly clean and not be damaged in any way. Components with damaged sealing faces must be replaced. MS 171, MS 181, MS 211...
(arrow). : Open the shutter (1), if fitted, and push it out of its seat (arrow). – Check the shutter and replace it if necessary. – Install in the reverse sequence. MS 171, MS 181, MS 211...
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– Pass the ends of the strings reverse sequence. hose is attached. through the bores (arrows) and position the manifold flanges – Tightening torques, b 3.5 against the bores in the carburetor carrier (1). MS 171, MS 181, MS 211...
0000 850 1300 to the nipple (arrow) – subject the fuel tank to a vacuum. Equalization of pressure takes place via the tank vent. There must be no build-up of vacuum in the tank. MS 171, MS 181, MS 211...
All manuals and user guides at all-guides.com 14.8.2 Removing and Installing – Coat seat of tank vent with STIHL – Remove the filter base, b 14.2 Press Fluid, b 16 – Remove the carburetor, b 14.3 – Remove the handle frame, : Press the tank vent into its seat b 11.4...
– Push the fuel pump into the fuel hose (1). : Line up the lug (3) with the recess (arrow) and push the fuel pump (2) into the bore until the retaining tabs engage. MS 171, MS 181, MS 211...
Tightening torques, b 3.5 – Remove the tank vent, b 14.8.2 : Pull off and inspect the fuel hose (1) and replace if necessary. – Install in the reverse sequence. MS 171, MS 181, MS 211...
– Check the tank cap and replace sealing ring or tank cap. – Install in the reverse sequence. – Carry out leakage test. : Push the connector (1) into the grommet and locate it on the web (arrow). MS 171, MS 181, MS 211...
Setting gauge 1111 890 6400 Adjusting air gap between ignition module and flywheel Ignition system tester, ZAT 4 5910 850 4503 Testing ignition system Ignition system tester, ZAT 3 5910 850 4520 Testing ignition system MS 171, MS 181, MS 211...
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T-handle screwdriver, T 27 x 150 5910 890 2400 IS-P screws (4 mm) Crimping tool 5910 890 8210 Attaching connectors to electrical wires Pliers DIN 5254-A 19 0811 611 8380 Removing and installing external circlips Remarks: 1) Use for releasing only. MS 171, MS 181, MS 211...
0786 111 2109 adhesive (Loctite 270) High-strength threadlocking 0786 111 2117 adhesive (Loctite 648) Standard commercial solvent- Cleaning sealing faces and carburetor, based degreasant containing no crankshaft stubs and flywheel taper chlorinated or halogenated hydrocarbons MS 171, MS 181, MS 211...
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All manuals and user guides at all-guides.com englisch / english 0455 533 0123. M7. F7. FST. Printed in Germany...
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