STIH) STIHL MS 241 C 2010-11
Contents 1. Introduction and safety precautions 3 1.1 1.2 Introduction Safety precautions 3 4 2. Specifications 5 2.1 2.2 2.3 2.4 2.5 Engine Fuel system Ignition system Chain lubrication Tightening torques 5 5 5 5 6 3. Troubleshooting 8 3.1 3.2 Clutch Chain Drive, Chain Brake, Chain Tensioner Chain lubrication Starter Ignition system Carburetor Engine 8 3.3 3.4 3.5 3.6 3.7 4. 4.1 4.2 Clutch drum Clutch 5. Chain brake 5.
Contents 10. 10.1 10.2 10.3 10.3.1 10.3.2 10.3.3 10.4 10.4.1 11. Maintaining the antivibration elements 94 Antivibration element on oil tank Antivibration element on fuel tank Antivibration element on front handle Antivibration element on handlebar, version with heating Stop buffer Filter base buffers Front handle Handlebar with heating 100 Actuating levers 105 94 13. Fuel system 115 14. 13.1 13.2 13.3 13.4 13.4.
Introduction and safety precautions 1.1 Introduction Refer to the illustrated spare parts lists during all repair work. These lists show the installation position and order in which the individual parts and modules should be assembled. Refer to the latest edition of the relevant spare parts list to check the part numbers of any spare parts required. A fault on the machine may be due to several causes.
Preparing to make repairs 1.2 Before repair tasks or clamping on the assembly stand, always remove the chain sprocket cover, saw chain and guide bar. Always use original STIHL replacement parts. They can be identified by the STIHL part number the logo { and the STIHL parts symbol K The symbol may appear alone on small parts. Storage or disposal of oil and fuel Collect fuel or lubricating oil in a clean container and dispose of it in accordance with environmental regulations.
2. Specifications 2.1 Engine MS 241 C Displacement: Bore: Stroke: Engine power to ISO 7293: Max. permissible engine speed (with bar and chain): Idle speed: Clutch: Clutch engages at: Crankcase leakage test at gauge pressure: under vacuum 2.2 42.6 cm3 42.5 mm 30.0 mm 2.2 kW (3.0 HP) at 10000 rpm 14000 rpm 2800 rpm Centrifugal clutch without linings 3500 rpm pü = 0.5 bar pu = 0.5 bar Fuel system Carburetor leakage test at gauge pressure: Operation of tank vent at gauge pressure: Fuel: 2.3 pü = 0.
2.5 Tightening torques DG and P screws are fitted in plastic and light alloy metal parts. These screws form a permanent thread when they are installed for the first time. The material is permanently deformed. Screws can be removed and installed as often as necessary without impairing the strength of the screwed assembly, provided that the specified tightening torque is observed. For this reason it is essential to use a torque wrench.
Fastener Thread size For component Tightening torque Nm Carrier Screw Screw Screw Nut Nut Screw Screw M 12x1 L D 4x12 M 5x16 M 5x16 M 8x1 M 12x0.75 P 4x10 D 4x12 M 10x1 D 4x20 M 5x20 M 5x20 Crankshaft carrier Oil pump / crankcase Muffler / crankcase Muffler / cylinder Flywheel / crankshaft Switch Support Pre-separator / crankcase Spark plug / cylinder Control unit / cylinder Cylinder / crankcase 1st stage Cylinder / crankcase 2nd stage 50.0 4.0 10.0 10.0 28.0 2.0 1.0 4.0 12.0 4.5 4.0 10.
3. Troubleshooting 3.
3.
Problem Cause Brake cable stretched QuickStop Super Coasting brake is not released although trigger interlock is pressed Brake cable unhooked or broken Excessive play on trigger interlock QuickStop Super Brake band is not released although trigger interlock is pressed QuickStop Super Coasting brake does not brake properly – trigger interlock not pressed 10 Remedy Adjust brake cable Reattach or replace brake cable Adjust brake cable Brake cable overstretched Adjust brake cable Sleeve of the brake cab
3.3 Chain lubrication In the event of trouble with the chain lubrication system, check and rectify other sources of faults before disassembling the oil pump. .
3.4 Starter Problem Cause Remedy Starter rope broken Rope pulled out too vigorously as far as stop or over edge, i.e.
Problem Cause Remedy Starter rope is difficult to pull or rewinds very slowly Starter mechanism is very dirty Thoroughly clean complete starter mechanism At very low outside temperatures: Lubricant oil on the rewind spring becomes viscous (spring winding stick together) or moisture has penetrated the rewind spring (spring windings are frozen) Coat rewind spring with a little standard solvent-based degreasant (containing no chlorinated or halogenated hydrocarbons), then pull rope carefully several tim
3.
3.
Problem Cause Remedy Engine will not idle, idle speed too high Throttle shutter is not closed properly when the throttle trigger is not pressed Examine carburetor and throttle rod, replace if necessary Oil seals or crankcase leaking Seal oil seals or crankcase, replace if necessary Throttle shutter does not close Replace carburetor Idle jet bores or ports blocked Clean the carburetor Idle jet too rich or too lean Check M-Tronic Tank vent faulty Replace tank vent Leak in fuel line between tan
Problem Cause Remedy Engine speed drops quickly under load – low power Air filter dirty Clean air filter, replace if necessary Throttle shutter not opened fully Check throttle rod Tank vent faulty Replace tank vent Fuel pick-up body dirty Replace pickup body Fuel strainer dirty Clean fuel strainer in carburetor, replace if necessary Leak in fuel line between tank and carburetor Seal connections or replace line Carburetor setting too lean Check M-Tronic Main jet bores or ports blocked Clea
3.
4. Clutch 4.
Chain brake 5.1 Checking operation of chain brake The chain brake is one of the most important safety devices on the chain saw. Its efficiency is measured in terms of the chain braking time, i.e., the time that elapses between activating the brake and the saw chain coming to a complete standstill. Fouling (particularly with chain oil, chips, fine particles of abrasion, etc.) and smoothing of the friction surfaces of the brake band and clutch drum impair the coefficient of friction.
Installation 5.3 Brake lever – Troubleshooting, b 3.2 1 1 2410RA012 TG 2410RA009 TG 2 2 – Remove shroud, b 6.4 – Remove fan housing, b 9.2 – Remove brake band, b 5.
– Examine pins and replace if necessary, b 5.
– Unhook and remove the brake spring at the brake lever 1 – Position the protective tube so that it starts after the second turn (arrow) : Use the assembly tool (2) 1117 890 0900 to attach the brake spring (1) to the anchor pin (arrow) : Unhook brake spring (1) from anchor pin (arrow) – Grease brake lever, cam lever and hand guard motion link, b 16 – The pin for the brake spring must be replaced if it shows signs of wear at the groove, b 5.
Installation 1 1 – Clean pins and disassembled parts, b 16 2 2410RA032 TG 2410RA028 TG – Grease pins, b 16 2 : Disconnect brake cable (1) : Slide hand guard (1) with brake lever (2) across the machine until it rests against the anchor pins (arrows) 1 : Pull brake lever (2) out of hand guard (1) – Examine cam lever and replace if necessary, b 5.
: Attach brake spring (1) to anchor pin (2) 2410RA025 TG : Turn cam lever (1) aside until cam of hand guard (arrow) slides past : Use the assembly tool 1117 890 0900 to hook the brake spring (1) onto the anchor pin (arrow) 1 – Press bearing eye of hand guard and brake lever onto the anchor pins 5902RA040 TG 2410RA034 TG 1 The turns of the brake spring must be tightly spaced when not installed; use a new brake spring if necessary.
Adjust brake cable : Screw in adjusting screw (2) – Play increases : Unscrew adjusting screw (2) – Play decreases 1 : Once play is adjusted correctly, tighten clamping screw (3) 2 2410RA039 TG 2410RA038 TG 1 – Press and hold the trigger interlock down completely : Remove screw (1) 1 : Lower tank housing (2) 2410RA038 TG Brake band (1) must rest against the crankcase (arrows) without play and the clutch drum must rotate freely.
5.4.2 Brake cable Removal and installation : Push hook (1) through the support (2) with a gentle twisting motion 1 – Unhook brake spring, b 5.4 – Remove QuickStop Super throttle trigger, b 11.3 – Remove QuickStop Super trigger switch, b 11.3.
– Reassemble remaining parts in reverse order 1 1 – Adjust brake cable and check operation, b 5.4.1 1 2 When raising the tank housing, make certain that the sleeve (1) is pushed completely into the adjusting screw (2) – incomplete insertion of the sleeve changes the setting of the brake cable. 5.5 The cam lever defines the engaged position of the hand guard. – Remove brake lever, b 5.3, QuickStop Super, b 5.4 2 2410RA044 TG – Check position of the fuel hose and correct it if necessary, b 13.11.
5.6 The pins ensure that the springs are securely mounted. They must therefore be replaced when worn, otherwise the springs may pop out. : Check condition of cam guide (arrow) and replace hand guard if necessary : Push circlip (1) into place 2 : Hook brake spring (1) into the brake lever so that the opening of the anchor loop (arrow) is visible : Hook brake spring (1) onto pin (2) 3 6 1 4 5 : Remove pins (1) through (6) Item 6 is present only in the version with QuickStop Super.
Installation Machines with QuickStop Super a 1 2 : Drive in anchor pins (5) and (6) in accordance with the following information a 3 5 : Drive in anchor pins (3), (4) and (5) in accordance with the following information 6 b 2410RA059 TG 4 2410RA056 TG Turn the pin back and forth slightly until it fits. The pins must be driven in square. 6 : Pin (1) a = approx. 2.9...3.3 mm Pin (2) b = approx. 4.3...4.
Chain tensioner 5.7.1 – Troubleshooting, b 3.2 Quick chain tensioner The quick chain tensioner is built into the chain sprocket cover. 1 2410RA063 TG 5.
5.7.2 Chain catcher – Reassemble remaining parts in reverse order – Remove the chain sprocket cover 2 2410RA300 TG 1 : Remove screw (1) and pull out chain catcher (2) under the bumper strip This chain sprocket cover can only be used on the MS 241. It cannot be retrofitted to other models. The length and shape of the stud must be appropriate for the chain sprocket cover with captive nut. The special tool stud 5910 893 9600 is available for replacing the nut.
Installation 2410RA068 TG 1 : Push in new collar nut (1) 2410RA069 TG 1 – Hold the hexagon of the collar nut in place : Screw the assembly tool (1) 5910 893 9600 with the long stud into the opposite side of the collar nut as far as it will go Now the new collar nut has been flanged and secured in the chain sprocket cover.
Engine 6.1 Muffler Check and if necessary repair the fuel supply, carburetor, air filter and ignition system before looking for faults on the engine. – Troubleshooting, b 3.7 – Remove and install spark arresting screen, if present, see Instruction Manual 2 To keep dirt particles from entering the cylinder, move piston to top dead center before removing the muffler.
2 c Defective oil seals and gaskets or cracks in housing are the usual causes of leaks. Such faults allow supplementary air to enter the engine and upset the fuel-air mixture. Moreover, the transition from idle speed to part or full throttle is not smooth. Always start with the vacuum test and then continue with the pressure test. The engine can be thoroughly checked for leaks under vacuum and at gauge pressure using the pump 0000 850 1300. 6.2.
4 1 3 3 2 : Washer (1) must be fitted : Push the hose (1) of pump 0000 850 1300 onto the connector (arrow) 1 : Slide ring (2) to the left – Vacuum test 2 2410RA079 TG 2 : Orient flange (1) 1118 850 4200 and push it onto the studs : Fit flange (1) 1118 850 4200 : Tightly screw on nuts (2) 6.2.2 : Operate lever (3) until the pressure gauge (4) indicates a vacuum of 0.5 bar If the vacuum reading remains constant, or does not decrease by more than 0.
6.3 Oil seals Installation It is not necessary to dismantle the complete engine if only the oil seals need to be replaced. – Clean the mating surface, b 16 – Clean the cone of the crankshaft to ensure it is completely greasefree, b 16 – Grease the sealing lips of the new oil seal, b 16 – Reassemble remaining parts in reverse order Pull out oil seals using puller 5910 890 4400 and jaws (profile no. 6) 0000 893 3711. 6.3.1 6.3.2 2 Clutch side – Remove the clutch, b 4.
: Remove the installing sleeve (1) 6.4 Shroud 1 2 2410RA090 TG 1 2410RA088 TG 2410RA086 TG 1 Avoid damage to the crankshaft stub. – Free the oil seal in its seat by tapping it with a suitable tube or a punch. : Orient press sleeve (1) 1118 893 2401 with the collar (arrow) facing the engine : Position puller (1) 5910 890 4400 : Use the press sleeve (1) 1118 893 2401 to install the oil seal (2) – Clamp the puller arms : Remove the shroud (1) The seating face must be flat and free from burrs.
Installation – Remove the carburetor, b 13.5 – Remove carburetor support, b 13.8 : Push in cap (1) with drift (2) – Reassemble remaining parts in reverse order 6.5 Cylinder Before removing the cylinder, decide whether or not the crankshaft is to be removed. 2410RA094 TG 1 – Remove the muffler, b 6.1 : Carefully pull off the cylinder (1) – Remove the decompression valve, b 6.9 – not for version with ErgoStart – Remove the front handle, b 10.
Installation 2 2 2 1 1 : Examine the intake elbow (1), replace if necessary. Engine operation may be impaired even by the slightest damage, b 3.7 2 2410RA099 TG 2410RA097 TG 2 1 : Fit clamping strap (1) 0000 893 2600 around piston and piston rings : Remove intake elbow (1) – Ensure that piston rings are correctly positioned, b 6.8 The clamping strap (1) must be fitted in such a way that the piston rings do not protrude beyond the piston sides.
6.6 Crankshaft Clutch side half of crankcase – Drain fuel tank and oil tank, b 1.1 2 1 – Remove brake band, b 5.2 : Remove clamping strap (1) and wooden assembly block (2) Make certain that the cylinder gasket is oriented according to the holes. – Remove oil pump, b 12.3 2410RA106 TG 2410RA104 TG 1 – Remove oil suction hose, b 12.2 – Remove brake lever, b 5.3 QuickStop Super, b 5.4 : Remove the circlip (1) – Remove the front handle, b 10.4 Version with heating, b 10.4.
Ignition side half of crankcase 1 : Unscrew screw (1), remove Loctite residue from the threaded hole if necessary 2410RA109 TG 2410RA544 TG 2 1 : Align the assembly tool (1) with the disk (2) 5910 893 2103 against the ignition-side half of the crankcase so that the edge number "24" (arrow) is at the bottom : Insert three M5 x 72 screws (3) through the holes marked "24" and screw them as far as possible into the crankcase half : Remove the gasket (1) : On versions with quick chain tensioner, remove
Installation 2 Ignition side half of crankcase Avoid damage to the crankshaft stub. If the inner race cannot be heated, the crankshaft can be drawn into the crankcase with the assembly tool 5910 007 2201. – Use disk 5910 893 2103.
1 1 22 24 23 22 24 2410RA118 TG The crankshaft also turns when it is drawn in with the installing tool. For this reason, ensure that the rod eye (1) always faces upwards towards the cylinder. : Fit a new gasket (1) and secure it at the guide sleeves (arrows) – Wear protective gloves – risk of burns – Coat the cylindrical crankshaft stub with oil – Heat only the inner race of the ball bearing to approx.
– By turning it, screw the spindle completely into the assembly tool : Screw the threaded sleeve (1) 5910 893 2409 onto the spindle as far as it will go – Left-hand thread : Hold crankshaft steady and screw threaded sleeve onto thread of crankshaft stub by turning the spindle counterclockwise 2410RA119 TG 2410RA121 TG 165RA133 TG 1 Ensure that the guide sleeves (arrows) line up with the holes and that the housing gasket is not jammed or buckled.
6.6.1 Ball bearing / crankcase Ignition-side half of the crankcase Those parts which are not supplied with the new crankcase must be removed from the old crankcase, examined and replaced if necessary. – For versions with quick chain tensioner, fit side plate : Coat screw (1) with Loctite, screw in and tighten, b 16 When fitting a new crankcase, the machine's serial number must be stamped on the crankcase with 2.5 mm figure stamps.
Installation – Replace ball bearings if the crankcase is in good condition The ball bearing must be fitted rapidly, as it absorbs heat and expands. – Heat the bearing seat of the ball bearing to approx. 150 °C (300 °F) – Position ball bearing so that the open side (balls visible) faces the inside of the crankcase : Press the grooved ball bearing home as far as possible – Remove oil pump, b 12.
Installation 1 – Coat needle bearing with oil and slide it into the rod eye If the piston pin is stuck, tap the end of the drift gently with a hammer to loosen it. The piston must be held steady during this process to ensure that jolts are not transmitted to the connecting rod. – Examine the piston rings and replace if necessary, b 6.
6.8 Piston rings – Remove piston, b 6.7 : Position the installing tool 5910 890 2210 with the taper sleeve on the piston boss, hold the piston steady and press the tool shank home until the snap ring slips into the groove : Use a piece of old piston ring to scrape the grooves (arrows) clean 2410RA137 TG : Remove sleeve and fit it over the opposite shaft end of the assembly tool, with the internal pin pointing towards the flat surface. – Examine the piston rings and replace if necessary, b 6.
6.9 Decompression valve – Remove shroud, b 6.4 2410RA140 TG 1 : Position the piston rings so that the radiuses at the ring gaps encircle the fixing pins in the piston grooves (arrows) 2410RA141 TG – Carefully slide the piston rings over the piston – danger of breakage : Unscrew decompression valve (1) : Check the correct installed position of the piston rings again (arrows) – Reassemble remaining parts in reverse order 5902RA164 TG – Install the piston, b 6.
Ignition system Exercise extreme caution while carrying out maintenance and repair work on the ignition system. The high voltages which occur can cause serious or fatal accidents. Troubleshooting on the ignition system should always start with the spark plug, b 3.5 – Remove fan housing, b 9.2 Testing of the ignition module is not limited to only a spark test.
Installation 1 2 2410RA148 TG 1 2410RA146 TG 1 : Remove screws (1) with washers : Position cable holder (1) on the cylinder and secure it with the pins on the cylindrical raised parts – Remove control unit 2410RA150 TG 1 : Position ground wire (1) so that the cable lug is pressed fully home (arrow) and the crimped side faces the screw head : Insert screw (2) with washer – do not tighten 3 – Check ignition lead, replace if necessary – Examine the spark plug boot, replace if necessary, b 7.
1 1 2 Shown without setting gauge for a better view.
: Press ignition lead (1) completely into the guide (arrow) – Note routing of the ignition lead, see illustration Ignition lead and spark plug boot must not touch the air guide shroud. Spark test check control unit The ignition test refers only to a spark test, not the general functions of the control unit; these are described in the M-Tronic chapter, b 8.2, b 8.5. To spark test the control unit, use either the ZAT 4 ignition system tester 5910 850 4503 or the ZAT 3 ignition system tester 5910 850 4520.
5 While using the ZAT 3, hold it only by the handle (4) or position it in a safe place. Keep fingers or other parts of your body at least 1 cm away from the spark window (3), high-voltage connection (2), ground connection (5) and the ground terminal (1). Danger! High voltage – risk of electrocution.
7.5.1 Ignition lead The ignition lead is built into the high voltage output of the control unit. If the ignition lead is damaged, the control unit must be replaced. – Before twisting in the ignition lead, fill the coil tower with STIHL multi-purpose grease, b 16 – Block the piston with the locking strip, b 4 Do not use either graphite grease or silicone insulating paste. – Remove spark plug boot, b 7.5 1 2 2410RA164 TG – Remove the control unit, b 7.
– Reassemble remaining parts in reverse order 7.7.2 Removal and installation – Remove shroud, b 6.4 The flywheel and magnet poles (arrows) must not display any signs of damage or blue discoloration; replace flywheel if necessary. – The magnet ring must also be examined for signs of damage in versions with handle heating, b 7.6 – With versions with ErgoStart pawls, check for damage and smoothness of motion, b 9.4.
1 : Remove screw (1) with washer and remove ground wire cable lug (2) 2410RA170 TG 2410RA167 TG 2 : Remove blade receptacle (1) of the carburetor heating lead 2410RA171 TG 1 1 : Pull plug connector (1) out of the carburetor support mount (arrow) Versions with manual fuel pump 1 1 2 : Remove wiring harness (1) and ground wire (2) from the guides (arrows) Versions with heating 3 : Push out the holder (1) with the fuel pump at the air guide shroud (2), remove fuel hose (3) at the carburetor (a
1 2 2 : Pull out grommet (1) with wiring harness 1 2410RA175 TG 1 2410RA179 TG 2410RA176 TG 2 MS 241 C 2 : Pull blade receptacles (1) out of the insulating sleeve (2) – Check blade receptacles and insulating sleeves, clean or replace insulating sleeves if necessary 1 : Remove wiring harness (1) from the guides (arrows) of the air guide shroud 2410RA180 TG 1 1 : Remove ground wire (1) from the guides (arrows) : Pry out and remove the cable holder (1) at the pin (arrow) : Pull the retaining
Installation 1 The ground wire (4) must be routed behind the protective tube (2) – facing the cylinder. 1 2 3 : Close and lock the cover (1) so that the tab (2) engages the slit (arrow) of the retaining tab (3) – the retaining tab must fit snugly against the insulating sleeve : Push the grommet (1) into the opening (arrow) in the air guide shroud (2) until it is flush with the edge of the air guide shroud The leads must not be reversed.
4 1 2 : Press the red M-Tronic lead (1), ground wire (2) and black lead (3) of the short-circuit wire all the way into the guides (arrows) 2410RA192 TG 5 1 2410RA190 TG 3 2 2 : Check that the leads are properly seated in the guides and press the cable holder (1) with the pin (arrow) into the mount until it snaps into place The protective tube (4) must start at the beginning of the rib and protective tube (5) must rest against the beginning of the rib.
2 1 : Orient plug (1) and jack (2) that the tab (3) lines up with the mount (arrow) – do not twist the leads 2410RA199 TG 1 2410RA188 TG 2 : Slide the blade receptacle (1) of the blue ground wire, with the crimped side facing the cam (2), into the guide (arrow) as far as it will go : Plug connector (1) into jack (2) until the tab (3) clicks into place in the mount (arrow) 2410RA201 TG 1 3 2 : Check the routing of the blue ground wire (1) and black shortcircuit wire (2), if necessary, press them
Versions with heating : Press fuel return line (3) completely into the guide (arrow) 1 2410RA227 TG 2410RA198 TG 2410RA204 TG 1 1 : Orient blade receptacle (1) so that the crimped side faces the carburetor : Press blade receptacle (1) onto the connector tab (arrow) of the heating switch as far as it will go : Press ground wire (1) completely into the guide (arrow) – Ground wire is routed underneath the wiring harness Push the new fuel suction hose (1) completely onto the connectors (arrows) 1 Al
a 7.7.4 1 Contact spring The short-circuit wire must be seated firmly in the eye of the contact spring, if necessary, carry out a contact and continuity test, b 7.7.1. 1 : Press wiring harness (1) completely into the guides (arrows) : Press the wiring harness (1) into the guide so that the protective tube (2) a = approx. 8 mm is seated in the guide (arrow) – Ground wire is routed underneath the wiring harness – Check the air gap between control unit and flywheel, adjust if necessary, b 7.
2 1 1 : Press contact sleeve (1) of the short-circuit wire out of the contact spring (2) : Position contact spring (1) against the guide (arrows) – Examine contact spring, replace if necessary : Lift contact spring (1) slightly at the connection of the short-circuit wire and guide it over the tab (2) – do not overextend the contact spring 2310RA154 TG 1 2410RA212 TG 2410RA210 TG 2 : Push the contact spring (1) into the guide (arrows) as far it will go, until the tab surrounds the contact spring – I
7.8 Troubleshooting, ignition system Engine does not run Stop switch: – in position "F"? Check spark plug: – Smeared with oil, black? – Sooted? – Electrode gap correct? – Contacts shorted (threads)? – Clean, adjust or replace spark plug, b 7.5 Check spark plug boot: – Firmly seated on spark plug (torsion spring)? – Torsion spring hook in center of ignition lead? – Spark plug boot damaged? – Replace spark plug boot and/or torsion spring if necessary, b 7.
1 Spark present? yes no Air gap: – Check control unit/ flywheel, – adjust if necessary, b 7.3 Check flywheel: – Have pole shoes turned blue? – Replace flywheel if necessary, b 7.6 Check short circuit wire: – Wire damaged? – Plug connections firmly seated? – Check continuity, replace wiring harness if necessary, b 7.7.1 Check ignition lead: – Severe chafing? – Spark plug boot: Holes / cracks? – Resistance of spark plug boot to ground: Required 1.5...
2 3 Switch shaft Check correct operation: – Short circuit wire chafed? – Function between contact spring and contact of the switch shaft: – Position "F" = no connection – Position "0" = connection – Replace wiring harness if necessary, b 11.1 Spark present? yes no Control unit needs to be replaced, b 7.
8. M-Tronic 2410RA546 TG 8.1 The fully electronic M-Tronic engine management system controls the ignition timing and fuel flow, taking all external conditions into account. A basic or standard setting of the carburetor is no longer required. The M-Tronic electronically adjusts the fuel-air mixture in the carburetor. The M-Tronic controls all operating states such as start, idle, part throttle and full throttle while accounting for the external conditions, e.g.
8.2 Testing 8.2.1 Test preparations The following steps must be carried out before testing. 1 – Remove shroud, b 6.4 – Remove the air filter, b 13.1 2410RA216 TG – Carry out troubleshooting according to troubleshooting chart, b 8.
Versions with heating All versions 1 1 5 2 Screw (1) must be tight. Leads (arrows) must be seated completely and firmly in the blade receptacles and the cable lug. 2 : Remove blade receptacle (1) and contact sleeve (2) : Push out the holder (3) with ground wire (4) at the air guide shroud (5) and lay it aside 1 2410RA221 TG 1 2410RA219 TG 2410RA217 TG 3 4 Plug (1) must be seated completely and firmly in the recess of the solenoid.
Versions with heating 1 3 : Push the holder (1) with the ground wire (2) into the recess in the air guide shroud (3) as far as it will go 2410RA225 TG 2410RA223 TG 1 2 : Push blade receptacle (1) onto the connector tab – Push on blade receptacle all the way : Press lead (2) completely into the guide (arrow) of the filter base – Reassemble remaining parts in reverse order 8.2.
Measuring resistance 1 2 1 2 2410RA166 TG 2410RA222 TG 2410RA228 TG 1 : Measure resistance between plugs (1) and (2) of the M-Tronic test lead : Set Master Control lever (1) to position }; the cam on the lever (2) must actuate the microswitch (arrow) – clicking sound Target value: between 28 and 42 ohms Versions with manual fuel pump – Set Master Control lever to position } – Push out the holder with the fuel pump and set it aside, b 8.2.3 – Connect the test lead, b 8.2.
Versions with manual fuel pump 2 Checking the ground connection – Connect M-Tronic test lead to multimeter : Insert black plug (1) in the "com" / "ground" jack and the red plug (2) in the "volt" / "ohm" jack – Set multimeter to "diode test" : Test diode on switchgear (3) (microswitch) in accordance with multimeter instruction manual If the switchgear (microswitch) is intact and the Master Control lever is set to the } position, the following target values will be attained: 1 – Install holder with heati
– Connect the test lead, b 16 2 – Check continuity between leads and blade receptacles – Blade receptacles must be firmly connected to the leads; in the event of contact problems, the wiring harness must be replaced, b 8.2.3, b 8.2.6 Target value: < 10 ohms 1 Check leads between solenoid valve and diagnostic jack 1 2410RA233 TG – Connect the test lead, b 8.2.2 – Versions with manual fuel pump, remove fuel pump and set it aside, b 8.2.
Wiring harness Versions with heating – The M-Tronic leads and the ground wire are all combined into one wiring harness; removal and installation are described in the chapter "Short-circuit wire", b 7.7.2 1 Switchgear – Remove shroud, b 6.4 1 2410RA240 TG 2 8.4 All versions : Remove blade receptacle (1) – Remove the air filter, b 13.1 2410RA243 TG 8.3 : Pull plug connector (1) out of the carburetor support mount (arrow) : Remove heating element (2) from the studs – Check switchgear, b 8.2.
1 1 2 The fuel hose does not have to be removed from the carburetor support. : Carefully pull out the carburetor with the fuel hose over the studs and lay it aside – do not overextend the fuel hose 3 : Pull the wiring harness (1) out of the guide (arrow) and pull it out between the special bolt (2) and the starter shaft (3) : Check lever on the starter shaft (3), replace if necessary, b 13.6.
1 Versions with manual fuel pump 2 1 3 2 : Position the wiring harness (1) so that the protective tube (2) rests against the beginning of the guide : Press the red and black leads completely into the guides (arrows) : Check seat of the fuel return line (1), if necessary.
Versions with heating Versions with manual fuel pump All versions 4 2 1 5 2410RA260 TG : Press thermostatic switch lead (1) completely into the guide (arrow) of the air guide shroud – Lead (1) must form a loop at the plug connection 2410RA259 TG 2410RA257 TG 1 1 : Push the holder (1) with the fuel pump into the mount of the air guide shroud (2) as far as it will go; push new fuel hose (3) onto the connectors (arrows) : Push the holder (1) of the switchgear over the studs so that the tab rests aga
8.5 Troubleshooting, M-Tronic 8.5.1 Engine does not start Engine does not start – Set Master Control lever to position } Can engine be started? yes no Troubleshooting completed – Test ignition system according to flow chart "Ignition system troubleshooting", b 7.8 no – Check ignition (spark plug, spark plug boot, ignition spark), b 7.4 yes Ignition spark present? yes Is it possible to start the engine? no – Check start detection, (microswitch, actuating lever), b 8.2.
8.5.2 Engine does not start in position } Engine does not start in position } – engine floods. Can the flooded engine be started in position F? Is it possible to start the engine? yes Troubleshooting completed no – Check start detection (microswitch actuation) clean if necessary Mechanically OK? no – Examine switch gear, clean or replace if necessary, b 8.2.5, b 8.4 yes – Check start detection, wiring harness and plug connections, b 8.2.5,b 8.2.3 Are target values attained?, b 8.2.
8.5.3 Engine speed drops under load – low power Engine speed drops under load – low power – Examine air filter, clean or replace if necessary, b 13.1 – Calibrate control unit, b 8.1 yes Troubleshooting completed 82 Machine OK? no – Look for a fault in the fuel path, check engine for leaks, b 13.11, b 6.
8.5.4 Ignition – no ignition spark No ignition spark – Set Master Control lever to position } Can engine be started? yes Troubleshooting completed no – Check the flywheel, (two pairs of poles?) b 7.6 Combination OK? no Establish correct control unit/ flywheel combination yes – Check air gap between control unit and flywheel, b 7.3 Air gap OK? no – Set correct air gap, b 7.3 yes – Test ignition system according to flow chart "Ignition system troubleshooting", b 7.
8.5.5 Engine stops suddenly Engine stops suddenly Machine OK? yes Troubleshooting completed no – Check fuel path (fuel pick-up body, tank vent, fuel hoses), b 13.11 Fuel path OK? no – Repair fuel system yes – Check plug connection on control unit or between wiring harness and switchgear Connection and firm seat of the plugs OK? no – Check plug connections, replace wiring harness and/or switching device, if necessary b 8.2.3, b 8.3, b 8.
8.5.6 Cut-off speed not reached Maximum speed less than 13000 rpm – Check air filter and spark arrestor screen (if present) in muffler, clean or replace if necessary, b 13.1, b 6.1 – Check saw chain tension and chain lubrication –Calibrate control unit, b 8.1 Maximum speed greater than 13000 rpm? yes Troubleshooting completed no – Check plug connection on control unit, b 8.2.
General If the action of the starter rope becomes very stiff and the rope rewinds very slowly or not completely, it may be assumed that the starter mechanism is in order but plugged with dirt. At very low outside temperatures, the lubricating oil on the rewind spring may thicken and cause the spring windings to stick together. This has a detrimental effect on the function of the starter mechanism.
9.3 Pawls Versions with ErgoStart – Remove ErgoStart, b 9.4 – Remove fan housing, b 9.2 1 2310RA206 TG – Relieve the tension of the rewind spring, b 9.5 2310RA204 TG 1 : Carefully ease the spring (1) off the starter post : Position the spring (1) so that the loop of the spring encloses the peg of the pawl and the curved part of the spring (arrow) is located in the groove in the starter post Two pawls are installed in the version with ErgoStart. Removal is the same as with the standard version.
ErgoStart Installation The spring may still have spring tension stored in it, thus release the spring tension before any assembly procedure: – Pull out the starter until the engine turns – the preloaded spring is relaxed Checking correct functioning The pawls must move freely and rest against the stop due to the spring force.
9.5 Rope rotor – Install pawl or pawls and spring, b 9.3 Relieve tension of rewind spring – Install starter rope, b 9.6 2 1 2310RA213 TG The system will not be under tension if the starter rope or rewind spring is broken. – Remove fan housing and segment, b 9.2 : Remove the washer (1) – Remove ErgoStart, b 9.4 The rewind spring must be relieved. All versions : Carefully pull off the rope rotor (2) –The rewind spring may pop out – Examine the rope rotor, replace if necessary.
1 4903RA132 TG : Push starter rope (1) out a short distance and undo the knot Pull the rope through the grip until the knot at the end of the rope is in the recess (arrow) – Pull starter rope out of rope rotor and fan housing. 2310RA218 TG 2310RA215 TG 1 : Pull starter rope (1) into rotor until the knot rests in the recess (arrow) of the rope rotor – Tension the rewind spring, b 9.7 – Reassemble remaining parts in reverse order 165RA227 TG 1 2310RA216 TG 9.
: Hold the rope rotor (1) steady : Pull out the twisted starter rope (2) with the starter grip and straighten it out Reduce spring tension Pull the rope out, hold the rope rotor steady and take off one turn of the rope. – Reassemble remaining parts in reverse order 9.8 2 Replacing the rewind Spring – Troubleshooting, b 3.4 The replacement spring is supplied ready for installation and secured in a spring housing. 2310RA221 TG 1 – Remove fan housing and segment, b 9.
Reinstalling a rewind spring that has popped out Versions with ErgoStart Install new rewind spring If the rewind spring pops out during installation, fit it in the fan housing as follows: 1 2310RA230 TG : Press the frame (1) against the rewind spring and turn it slightly clockwise until the rewind spring is completely seated The rewind spring may pop out.
Reinserting a popped out rewind spring into the frame 2310RA229 TG 1 Make certain that the rewind spring (1) is inserted completely and the outer anchor loop is seated in the anchor loop mount (arrow), if necessary, press the rewind spring completely into the mount in the fan housing. In versions with ErgoStart, the rewind spring mount sits lower, thus the rewind spring can only be inserted directly into the fan housing premounted in a frame.
Maintaining the antivibration elements The front handle / tank housing and crankcase are connected by vibration-damping springs, rubber buffers and stop buffers. 1 Antivibration element on oil tank The antivibration elements are located in the area of the oil tank and are fastened to the bottom of the machine. 2310RA233 TG Damaged springs rubber buffers and stop buffers must always be replaced. 10.
Versions with heating Installation 1 2 3 : Remove cover (1) : Remove screw (1) on front handle – Push tank housing down slightly and hold it there All versions 1 2310RA236 TG 2 2310RA238 TG 1 1 1 2310RA239 TG 2310RA237 TG 2410RA303 TG 1 : Push the antivibration element (1) slightly upward and lift it out of the guide (arrow) : Orient antivibration element so that the tab (1) faces the crankcase and push it bearing plug (2) first between crankcase and tank housing : Push bearing plug (2)
10.3 2 1 Antivibration element on front handle The antivibration element is between front handle and cylinder. 2410RA304 TG : Push tank housing upward until the peg (1) of the front handle engages in the mount (arrow) 2410RA306 TG – Remove shroud, b 6.4 1 – Remove the air filter, b 13.
Installation 2 1 1 1 0001RA219 TG 2410RA306 TG 2310RA244 TG 2 3 2 : Position bearing plug (1) against cylinder : Twist out bearing plug (1) and unhook retainer (arrow) : Push retainer (1) with the small nipple into the hole in the front handle (2) : Coat screw (2) with Loctite, screw in and tighten, b 16 : Twist out spring (2) and pull out retainer (arrow) : Twist spring (3) onto the peg (arrow) as far as it will go – Reassemble remaining parts in reverse order Installation 10.3.
– Replace stop buffer 1 10.3.3 Filter base buffers – Remove filter base, b 13.3 Installation 2410RA309 TG 2 : Position antivibration element (1) against front handle and cylinder 1 : Screw in the screw (2) and tighten it 2410RA311 TG 2 1 – Orient the stop buffer (1) on both sides – the conical pegs (arrow) facing the crankcase : Coat screw (3) with Loctite, screw in and tighten, b 16 – To simplify installation, coat the conical pegs with STIHL press fluid, b 16 10.3.
Installation : Lift front handle (1) slightly at the side and remove it from the guide (arrow). 2 1 1 : Push tank housing (1) upward and hold it there : Screw in the screw (2) and tighten it – To simplify installation, coat the conical pegs with STIHL press fluid, b 16 – Reassemble remaining parts in reverse order : Press the buffers (1) with the conical pegs completely into the holes (arrows) –to simplify assembly, twist the buffers while pressing them in 10.
Installation 1 2 – Position front handle 1 2310RA158 TG 2 : Lift front handle (1) with the peg (2) facing forward into the recess (arrow) until it is seated in the mount of the tank housing – Insert and tighten down the screws : Position bearing plug (1) of the antivibration spring against cylinder 2410RA303 TG 2410RA306 TG 1 : Remove screw (1) on front handle : Coat screw (2) with Loctite, screw in and tighten, b 16 1 1 2 – Reassemble remaining parts in reverse order 2310RA157 TG 10.4.
1 4 1 1 : Press pegs (1) out of the mount (arrow) and lower front handle (2) with tank housing 3 5 : Push insulating tube (1) toward the wiring harness and push insulating tube (2) toward the front handle heating element 0001RA240 TG 2 2410RA323 TG 2410RA319 TG 2 : Remove front handle (1) from the lower guide – Remove front handle Do not disconnect plug connection (3).
Installation 1 2 – Press the plug connection together completely, b 1 2410RA327 TG 1 : Press in the handle insert (1) as far as it will go 2410RA329 TG 2 The leads on the front handle are of different lengths; during assembly, take care that the short lead (1) is connected to the lead to the heating switch and the long lead (2) is connected to the lead to the handle heating element. 2410RA330 TG 1 Do not pinch the leads and plugs.
1 3 2 1 : Insert and tighten screws (1) – lines must be seated in the guide (arrow) – Tighten screws of the front handle on the underside of the machine : Push insulating tube (1) onto thick lead of the handle heating Plug connection with shorter lead of the front handle.
1 2 1 2410RA341 TG : Run the thin lead (1) with a loop (2) around the rib and press it into the guide (arrow) as far as it will go The leads of the handle heating element must be seated completely in the guide (arrow). : Push tank housing (1) upward and hold it there : Screw in the screw (2) and tighten it – Install throttle trigger, b 11.
Actuating levers 11.1 Master Control lever – Examine the filter base, replace if necessary The positions of the Master Control lever are described in the Instruction Manual. Installation 11.1.1 Removal and installation – Position filter base in the carburetor space 2 1 2310RA164 TG 11. – Remove the air filter, b 13.1 : Press the switch shaft (1) onto the post (2) of the filter base as far as it will go – Remove choke rod, b 11.4 – Remove the filter base from the studs, b 13.
Throttle trigger / throttle trigger interlock 1 3 1 2310RA167 TG 2 5902RA307 TG 1 2 : To disassemble the handle molding.
– Check correct functioning – Reassemble remaining parts in reverse order 2310RA172 TG 11.3 1 : Press the trigger interlock (2) into the bearing points (arrow) 2 Throttle trigger / throttle trigger interlock / QuickStop Super After each removal, coat sliding and bearing points with grease.
Installation 3 – Carefully fit handle molding (1) until it snaps into place 2 1 – Check correct functioning : Hook the torsion spring (1) into the throttle trigger (2) – Note the installed position (arrow) 2310RA182 TG 1 2310RA179 TG 2 – Reassemble remaining parts in reverse order : Center the throttle trigger (1) with punch (2) : Drive in the pin (3) until it is equidistant on both sides 11.3.1 Trigger switch QuickStop Super After each removal, coat sliding and bearing points with grease.
Installation 11.3.2 Trigger interlock QuickStop Super 1 Installation After each removal, coat sliding and bearing points with grease. – Remove handle molding, b 11.
11.4 Choke rod 1 – Remove the air filter, b 13.1 1 2 2410RA344 TG : Move switch shaft (1) to position "F" and pry out choke rod (2) at the mount (arrow) : Unhook the choke rod (2) from the lever (3) : Insert choke rod (1) in guide (arrow) : Move switch shaft (2) to position "F" and hold it there, then press choke rod (1) completely into the mount (arrow) Installation 2 Throttle rod – Remove handle molding and trigger interlock, b 11.2, QuickStop Super, b 11.3 – Remove choke rod, b 11.
1 2310RA296 TG 2 : Press the throttle rod (1) into the guide (2) on the carburetor support until it snaps into place – Install handle molding and trigger interlock, b 11.2, QuickStop Super, b 11.3 – Push carburetor with attached fuel hose onto the studs, b 8.4 – Install filter base, b 13.
12. Chain lubrication 12.1 Pickup body 12.2 Oil suction hose Impurities gradually clog the fine pores of the filter with minute particles of dirt. This prevents the oil pump from supplying sufficient oil to the bar and chain. Always check the oil tank and pick-up body first if problems develop in the oil supply. – Unscrew oil tank cap and drain oil tank, b 1 – Troubleshooting, b 3.3 – Remove oil pump, b 12.3 – Remove the clutch, b 4.2 – Remove brake band, b 5.2 – Install oil pump, b 12.
2 1 1 1 2 – Inspect spring and worm, replace if necessary : Remove sealing ring (1) – Examine oil pump, replace if necessary : Screw in screws (2) and tighten them Installation – Push the worm home until it makes contact 1 1 TOP 1 : Unscrew screw (1) and remove cover (2) 2410RA353 TG 2410RA350 TG 2 2410RA355 TG : Push in oil pump (1) as far as it will go 2410RA356 TG : Pull worm (1) with spring (2) out of oil pump 2410RA352 TG 2410RA349 TG 2 : Push new sealing ring (1) into the openin
12.4 Valve Installation A valve is installed in the tank wall to keep internal tank pressure equal to atmospheric pressure. The valve must be replaced if faulty. 1 2410RA318 TG – Unscrew oil tank cap and drain oil tank, b 1 Ensure that the parts are installed correctly.
Fuel system 13.1 Air filter 13.2 Dirty air filters reduce engine power, increase fuel consumption and make starting more difficult. The air filter should be checked when there is a noticeable loss of engine power. – Refer also to troubleshooting, b 3.6, b 3.7 Baffle 2 – Remove the air filter, b 13.1 2410RA237 TG 13. 1 1 2410RA263 TG – Remove shroud, b 6.
Installation 2 1 – Position filter base in the carburetor space 1 : Remove short circuit wire (1) and contact spring (2) from the guides (arrows) – Remove contact spring, b 7.7.4 : Press filter base (1) over the studs (arrows) onto the carburetor 2 3 – Remove switch shaft, b 11.
: Use wiring tool 5910 890 4000 to press the ground wire (1) into the guides (arrows) so that it lies snug against the air guide shroud and the marking (2) is at the edge of the guide 1 1 : Insert lead (1) completely in cable guide (arrow) 2410RA172 TG 2 2 2410RA169 TG 1 2410RA270 TG Versions with heating : Hold the jack (1), press the tab (arrow) and pull out the plug (2) – do not tug on the leads – Remove the carburetor, b 13.
1 : Pry out and remove the cable holder (1) at the pin (arrow) : Press the grommet (arrow) of the fuel hose (1) downward and out 1 2 : Pull the air guide shroud (1) over the buffers and out of the mounts, in the process, pushing the fuel hose (2) through the hole (arrow) 2 : Press tab (1) in the direction of the clutch side and pry the air guide shroud (2) out of the mount – Lay aside the wiring harness with the filter base 2 1 1 2 2410RA281 TG : Remove grommet (1) and wiring harness from the gui
Installation : Pull the grommet of the fuel hose (2) into the hole (arrow) in the air guide shroud (1) until the grommet entirely encloses the hole 2410RA284 TG : Push new fuel hose (1) through the opening (arrow) 1 2 : Slide the shutter (1) into the guide until it snaps into place : Orient the grommet (1) of the fuel hose (2) so the the straight side (arrow) rests against the edge of the air guide shroud 1 2 2 2410RA283 TG 1 : To pull the manifold flange (2) into the hole of the air guide shro
– Remove the throttle rod, b 11.5 1 – Remove carburetor support, b 13.8 : Guide the air guide shroud (1) over the buffers (2) and push the lugs into the mounts of the crankcase 2 : Push the grommet (1) into the mount until it is flush with the edge of the air guide shroud 2410RA293 TG 2 1 2410RA292 TG 2 2410RA289 TG 1 – Install wiring harness in the air guide shroud, b 7.7.2 1 2410RA290 TG 2 – Install the carburetor, b 13.
Installation 2 2 1 : Pull fuel hose (1) and fuel return line (2) out of the air guide shroud 2410RA442 TG : Press tab (1) in the direction of the clutch side and pry the air guide shroud (2) out of the mount 1 2410RA299 TG 2410RA296 TG 1 – Pull out the shutter and inspect it, replace if necessary – Remove the air guide shroud : Slide the shutter (1) into the guide until it snaps into place 2 : Ease out grommet (1) and examine it, replace if necessary – Replace fuel hose, b 13.11.
2 1 2 2410RA445 TG 2410RA283 TG 1 : To pull the manifold flange (2) into the hole of the air guide shroud, place a string (1) that is approx.
1 1 1 : Guide the air guide shroud (1) over the buffers (2) and push the lugs into the mounts of the crankcase : Orient the fuel return line (1) so that the marking (arrow) is located at the grommet (2) 3 2410RA453 TG 2410RA450 TG 2410RA451 TG 2 : Press the air guide shroud (1) into the mount until the tab (2) snaps into place 2 : Starting at the grommet (2), press the fuel return line (1) into the guides (arrows) – the marking (3) must be located at the upper guide rib 1 – Install the filter bas
1 1 2 : Pull contact sleeve (1) out of heating switch (2) : Slide insulating tube (1) towards generator and disconnect plug connection 3 2410RA460 TG 2 2410RA457 TG 2410RA454 TG 1 : Press tab (1) in the direction of the clutch side and pry the air guide shroud (2) out of the mount 3 2 1 : Remove lead (1) from the guides (arrows) 2 : Pull insulating tube (1) off of the generator lead (2) 2410RA461 TG 1 2410RA458 TG 2410RA455 TG 1 : Press tab (1) in the direction of the ignition side an
Installation 2 1 – Pull out the shutter and inspect it, replace if necessary – Pull the grommet off of the generator lead – to make it easier, twist the grommet while pulling it off 2 : Slide the shutter (1) into the guide until it snaps into place 2410RA464 TG 3 : Pull the fuel hose (1) out of the air guide shroud : Pull the wiring harness (2) out of the air guide shroud through the grommet (3) : Remove ground wire (1) from the guide (arrow) : Push the holder (2) with the heating switch out of th
– To simplify assembly, coat the manifold flange with STIHL press fluid, b 16 : Push grommet (1) onto the generator lead (2) so that the conical area (arrow) faces the generator – to make it easier, twist the grommet while pushing it on 1 2 2 : Fit the air guide shroud (1) The crimped side of the ground wire (2) must face the intake elbow.
: Position the air guide shroud (1) and pull the grommet of the fuel hose (2) into the hole (arrow) until the grommet completely encloses the hole 1 1 2 2 2410RA478 TG : Pull in wiring harness (1) until the protective tube (2) rests against the grommet 2410RA480 TG 2 2 Shown without piston and cylinder for a better view. The lugs (2) of the air guide shroud (1) must engage the mounts (arrows) of the crankcase.
4 1 2 1 5 2 3 1 : Pull in generator lead (1) and wiring harness (2) : Push together the connector (1) and the terminal socket (2) : Position cable lug (3) so that the crimped side faces upward and insert screws (4) : Slide insulating tube (3) over the plug connection : Push ground wire (5) into the guide (arrow) and tighten screws (4) : Push the contact sleeve (1) into the heating switch (2) as far as it will go 2410RA487 TG 2 1 2410RA483 TG 3 : Route generator lead (1) behind the wiring ha
All versions 1 1 : Push the grommet (1) into the mount until it is flush with the edge of the air guide shroud : Pull holder (1) of the switchgear over the studs (arrows) and lay it aside – Install wiring harness in the air guide shroud, b 7.7.2 Versions with manual fuel pump 2410RA243 TG 2410RA239 TG 2410RA292 TG 1 : Pull plug connector (1) out of the carburetor support mount (arrow) 2 – Install the filter base with the attached wiring harness, b 8.4 1 2410RA241 TG 13.
All versions – Examine the carburetor and repair or replace it if necessary, b 13.5, b 13.6 2 – Replace fuel hose, b 13.11.2 1 : Pull off carburetor (1) slightly and pull lead (2) out of the guide (arrow) 2410RA488 TG 2410RA470 TG Versions with manual fuel pump 1 : Disconnect the fuel hose (1) from the connector (arrow). – Replace fuel suction hose, b 13.11.3 Installation Versions with manual fuel pump : Disconnect the fuel hose (1) from the connector (arrow).
All versions : Push together the connector (3) and the terminal socket (4) 2 1 2 1 : Push new fuel hose (1) onto the connector (2) so that the tab (arrow) faces the throttle shaft lever and fits against the connector evenly Version with heating : Press the plug connection with insulating tube (1) into the center of the guide (arrow) 2410RA492 TG – Press the plug connection together completely, b 1 3 1 2410RA416 TG Washer (1) must be fitted.
All versions 1 Versions with manual fuel pump 2 1 4 : Push on the carburetor (1) further 2 2410RA188 TG 1 3 – Push on the carburetor as far as it will go – pay attention to cable routing and make sure not to pinch any leads 3 : Push the holder (1) with the fuel pump into the mount of the air guide shroud (2) as far as it will go; push new fuel hose (3) onto the connectors (arrows) : Fuel return line (4) must be seated completely in the guide (5); if necessary, press the fuel return line (4) into
All versions 1 : Push the holder (1) of the switchgear over the studs so that the tab rests against the pin (arrow) 2410RA506 TG 2410RA260 TG 1 2 : Push the fuel line (1) 1110 141 8600 onto the double connector (2) 0000 855 9200 : Push the fuel line with double connector onto the fuel port (arrow) 2 1 2410RA507 TG – Install the filter base with the attached wiring harness, b 8.
13.6.1 Metering diaphragm 2 1 2 1 – Remove the carburetor, b 13.5 2 1 2410RA357 TG : Carefully separate the metering diaphragm (1) and gasket (2) : Take out the screws (arrows) : Remove the end cover (1) The diaphragm material is subjected to continuous alternating stresses and eventually shows signs of fatigue. In other words, the diaphragm distorts and swells and must be replaced.
13.6.2 Inlet needle Ensure that the spring locates on the nipple of the inlet control lever. – Remove the metering diaphragm, b 13.6.1 165RA348 TG – Press the inlet control lever down and secure it with the screw. 1 2410RA372 TG 3 2 : The inlet needle must be replaced if a circular indentation (arrow) is visible on the tip of its sealing cone – Check that the inlet control lever moves easily – Install the metering diaphragm, b 13.6.1 13.6.3 Pump diaphragm – Troubleshooting, b 3.
Version with handle and carburetor heating – Examine the pump diaphragm for signs of damage and wear, fit a new gasket 1 3 1 1 2410RA362 TG 2 – Position the end cover (1) on the carburetor housing from below so that the gasket and pump diaphragm remain secured to the end cover : Remove screw (1) 2310RA267 TG : Remove thermostatic switch (2) : Remove the end cover (3) If the gasket and pump diaphragm are stuck to the carburetor, they must be removed very carefully.
1 2 3 1 1 2410RA367 TG 2 2410RA365 TG 2410RA374 TG 2 : Press lead (1) into the guides (arrows) so that is is behind the peg (2) : Remove screw (1) and pull out cable holder (2) : Press out the circlip (1) and remove the lever (2) : Slide on the insulating tube (3) Installation Installation 2 All versions 3 4 2410RA376 TG – Move the end cover (1) back and forth slightly until the pegs on the end cover engage in the holes in the carburetor housing 2410RA366 TG 1 1 : Orient the cable ho
13.6.6 Lever of the choke shaft – Remove the carburetor, b 13.5 – Troubleshoot carburetor, b 3.6 1 – Install carburetor, check correct functioning – Lever (1) must actuate the microswitch, b 13.5, b 8.2.5 – Reassemble remaining parts in reverse order 13.7 Carburetor bracket – Remove filter base with attached wiring harness and lay it aside, b 8.4 – Remove switchgear and carburetor and lay them aside, b 8.
3 2 2 – Remove carburetor support, check it and replace if necessary – Examine intake elbow, replace if necessary, b 13.
Versions with heating 13.9 Intake elbow A damaged intake elbow may lead to impaired engine performance. 1 2410RA548 TG – Troubleshooting, b 3.7 2410RA427 TG – Remove shroud, b 6.4 : Check seat of the lead (1) to the heating switch; if necessary. press it completely into the guides (arrows) – Remove the carburetor, b 13.5 : Examine and clean the mating surfaces (arrows), b 16 – Remove carburetor support, b 13.8 – Remove the air guide shroud, b 13.4 Versions with manual fuel pump, b 13.4.
Installation Pressure is equalized via the tank vent. A negative pressure must not build up inside the fuel tank. – Clean the area around the tank vent : Insert and tighten down the screws (arrows) 1 : Push the connector (1) 0000 855 9200 into the fuel hose (arrow) Testing with gauge pressure 2 Versions with manual fuel pump 1 – Install air guide shroud, b 13.4 Versions with manual fuel pump, b 13.4.1, Versions with heating, b 13.4.
13.10.2 Removal and installation – Remove shroud, b 6.4 2310RA365 TG 1 : Pry out the tank vent (1) via the mounting rib (arrow) Always fit a new tank vent.
13.11 Fuel intake 13.11.1 Pickup body Always check the fuel tank and pickup body first if problems develop in the fuel supply. – Troubleshooting, b 3.6 or b 3.7 1 : Use hook 5910 893 8800 to pull the pickup body (1) out of the fuel tank 2310RA372 TG 1 2310RA371 TG Impurities which are entrained into the fuel tank with the fuel are trapped by the pick-up body. With time, the fine pores in the pick-up body become clogged with very fine dirt particles.
Versions with QuickStop Super 2 2 Before lowering the tank housing, loosen the brake cable holder, because the sleeve of the brake cable can be pulled out of the adjusting screw when the tank housing is lowered – Brake cable adjustment can be negatively affected. 2410RA522 TG 2310RA378 TG 2310RA057 TG 1 1 1 : Remove connector (1) from fuel hose (2) – Use STIHL press fluid to simplify assembly, b 16 – Remove the pickup body, b 13.11.
Versions with QuickStop Super 2 2 1 1 : Push fuel hose (1) with the connector (2) in front into the fuel suction hose so that it is between the ribs (arrows) : Orient the fuel hose (1) so that it is underneath the brake cable (2) in accordance with the illustration and runs toward the ignition side Versions with QuickStop Super All versions 1 2310RA059 TG 2310RA525 TG 2410RA523 TG 2 : Press brake cable holder with the pin (1) through the opening and into the mount (arrow) : Screw in the screw (
Versions with heating – Install the carburetor support, b 13.8 1 Versions with QuickStop Super 2 – Install the carburetor, b 13.5 2 : Fit the plug (1) of the antivibration spring on the front handle : Screw in the screw (2) and tighten it 13.11.
2 1 1 : Pull out connector (1) with fuel return line (2) : Remove fuel suction hose (1), b 13.11.
1 1 2 13.11.4 Manual fuel pump 2 – Remove shroud, b 6.
1 13.11.5 Tank housing 1 2 – Empty the fuel tank, b 1 : Press the lugs (arrows) together and push out the fuel pump (1) – Examine fuel pump and replace if necessary 2410RA537 TG 2410RA535 TG – Remove the front handle, b 10.4 Versions with heating, b 10.4.1 : Push holder (1) with fuel pump (2) as far as it will go into the guides (arrows) of the air guide shroud 1 Installation 2 – Remove the carburetor, b 13.5 – Remove carburetor support, b 13.8 – Remove the air guide shroud, b 13.
All versions 3 – Examine the tank housing and replace it if necessary. 2 Those parts of the old tank housing which are not supplied with the new tank housing must be reused – see spare parts list.
Versions with QuickStop Super All versions 3 4 2 – Install air guide shroud, b 13.4 Versions with manual fuel pump, b 13.4.1, Versions with heating, b 13.4.
14. Heating 14.1 Carburetor heating Idling problems with a hot engine may also indicate a fault in the heating element of the thermostatic switch. 14.1.1 Check overall system In the function check of the overall system, the generator and heating elements are checked. Precondition is an ambient temperature of at least + 20 °C (68 °F). If the temperature is below + 13 °C (55 °F), the thermostatic switch may be closed and produce false readings.
Installation The thermostatic switch is an electronic component that cannot be tested directly. The functionality of the thermostatic switch can be determined using the troubleshooting chart, b 14.2 1 3 3 2 1 2410RA364 TG – Remove the carburetor, b 13.5 1 2 – Check that the pump diaphragm and gasket are correctly seated 2410RA374 TG 14.1.
14.2 Troubleshooting, carburetor heating Heating element resistance Measure when temperature = +20 °C (68 °F) Resistance approx. 12 Ω? Replace heating element, b 14.1.2 no yes Replace thermostatic switch, b 14.1.
14.3 Handle heating systems If the pointer does not move, there is a break in the circuit. 14.3.1 Troubleshooting The entire handle heating system is maintenance-free and not subject to electrical wear. Faults in the generator, heating elements and leads are generally caused by mechanical damage. Failures in the heating system may be due to two reasons: 1. 2. Interruption in the electrical circuit due to damage to leads or components.
14.4 Heating switch Installation 2 – Remove filter base, b 13.
2 : Orient socket terminal of the ground wire so that the connector tab (1) points toward the carburetor and the flat faces (arrows) engage between the fins (2) of the holder 2410RA389 TG 2410RA387 TG 2 : Fit washer (1) 1 2410RA392 TG 1 1 2 : Push the contact sleeve (1) into the heating switch (2) as far as it will go : Tightly screw on nuts (2) 1 – Position socket terminal at the holder : To ensure correct switch position, orient the heating switch (1) so that the groove faces the pin (arrow
14.5 Heating element in handle – Remove the handle molding and trigger interlock, b 11.2 If the heating element is intact, the ohmmeter will indicate a value of approx. 1.6 Ω (reading 1.5...2.0 Ω) in the measuring range "Ω". 1 1 Is the heating element inoperable despite a successful resistance measurement? 2 2410RA395 TG 1 : Pull insulating tubes (1) and (2) with plug connections out of the guides 2410RA396 TG The heating element must be replaced if the value is outside this range.
If the reading obtained is outside this tolerance, then the front handle (front handle heating element) must be replaced, b 10.4.1. The black lead of the handle heating must be routed underneath the gray lead of the wiring harness. : Press the leads of the handle heating and the wiring harness into the guide (arrows) – Reassemble remaining parts in reverse order 14.6 Heating element in front handle The heating element in the front handle cannot be replaced.
14.7 Generator Installation – Press the plug connection together completely, b 1 – Remove the control unit, b 7.3 – Remove the flywheel, b 7.6 0001RA448 TG – Remove the pre-separator, b 7.2 – Remove the carburetor, b 13.5 1 2410RA408 TG : Check generator and poles (arrow) for cracks or other damage. Replace generator if necessary. – Remove carburetor support, b 13.8 – Remove the air guide shroud, b 13.4.
1 2410RA413 TG : Lay generator lead (1) in bottom of recess (arrow) : Press generator lead (1) on the inside of the crankcase into the guide (arrow) so that it lies snug 1 1 : Press generator lead (1) into the guides (arrows) so that it runs snug against the crankcase The lead (1) must be seated completely in the recess (arrow). The flywheel must not touch the generator lead – power supply can be interrupted.
14.7.1 Troubleshooting chart, handle heating systems and generator Start yes Do both handles become warm? no Heating switch set to „F“? yes no Activate switch Measure resistance of the individual heating elements using ohmmeter Disconnect plug connection to thermostatic switch b 13.5 Check rear handle heating element: in good condition? Is it completely against the handle housing? no yes Resistance of handle heating element approx. 1.6 Ω? no Replace handle heating element, b 14.
1 3 2 Disconnect and clear plug connections to front handle heating element, b 10.4.1 check handle heating element resistance approx. 6.4 Ω? no Replace front handle, b 10.4.1 yes Test heating switch (contact sleeve against switch housing) Closed: approx. 0 Ω ? Open: no continuity, b 14.3 no Replace heating switch, b 14.4 yes Reassemble plug connection to thermostatic switch, b 13.
14.7.2 Summary of test connections and test values – The wires in the handle must be unplugged to test the individual components separately Component Switch Ohmmeter connection (either test lead can be used) Resistance Ω If faulty Lead 1 Required Actual Cause Remedy < 0.5 - Switch faulty Replace switch 1.6 1.5 - 2.
Component Generator Ohmmeter connection (either test lead can be used) Resistance Ω If faulty Lead 1 Lead 2 Required Actual Cause Connector to generator lead Weight 0.6 0.
: Disconnect plug connections and remove wiring harness (3) – Remove shroud, b 6.4 – Remove the handle molding and trigger interlock, b 11.2 Installation – Press the plug connections together completely, b 1 – Remove the carburetor, b 13.5 3 – Remove carburetor support, b 13.8 4 5 – Remove the air guide shroud, b 13.4.2 1 – Lower the tank housing and remove the cover of the plug connections, b 10.4.1 The wires of the handle must be seated completely in the guide (arrow).
In the absence of a fault in the wiring harness, heating elements, generator or heating switch, then the problem may also be due to damaged connecting leads between the front and rear handle heating elements. – Remove shroud, b 6.4 – Remove handle molding, trigger interlock and throttle trigger, b 11.2 – Lower the tank housing and remove the cover of the plug connections, b 10.4.1 2410RA425 TG 1 – Install cover over the plug connections, lift and fasten tank housing, b 10.4.
1 1 2 4 1 – Remove and examine connecting leads, replace if necessary 2410RA436 TG : Slide insulating tubes (1) towards connecting leads and disconnect plug connections 4 2410RA434 TG 2410RA432 TG 1 : Connect the thin connecting lead (1) with the thin lead (2) of the wiring harness and the lower lead (3) of the handle heating element : Position insulating tube (1) with plug connection at the edge of the tank housing and push it into the guide (arrow) as far as it will go 3 – Push connectors an
1 : Position insulating tube (1) with plug connection at the edge of the tank housing and push it into the guide (arrow) as far as it will go 3 2 1 2410RA440 TG 2 2 3 2410RA441 TG 2410RA439 TG 1 The thin connecting lead must be run underneath the thick connecting lead.
15. Special tools New special tools No. Designation Part No. Use 1 Press sleeve 1143 893 2400 2 Wiring tool 5910 890 4000 Pressing in oil seal (Ignition side) Inserting wires in the guides Remarks Existing special tools No. Designation Part No.
No. Designation Part No.
16. Service accessories No. Designation Part No.
englisch / english 0455 741 0123. M0,7. A11. DDS.
