STIH) STIHL MS 240, 260 2008-07
Contents 1. 2. 3. Introduction Safety Precautions Specifications 3 6 Engine Fuel System Ignition System Chain Lubrication Tightening Torquese 6 6 6 6 7 4. Troubleshooting 9 4.1 4.2 Clutch Chain Drive, Chain Brake, Chain Tensioner Chain Lubrication Rewind Starter Ignition System Carburetor Engine 9 5. Cutting Attachment Engine 8.1 8.6.2 8.7 8.7.1 8.7.2 8.8 8.
Contents 14.6 Throttle Rod 94 14.6.1 Removing and Installing the Intake Manifold 94 14.6.2 Impulse Hose 96 14.7 Tank Vent 96 14.7.1 Testing 96 14.7.2 Removing and Installing 97 14.8 Fuel Intake 98 14.8.1 Pickup Body 98 14.8.2 Fuel Suction Hose 98 14.8.3 Removing and Installing the Tank Housing 99 15. Heating System 100 15.1 Carburetor Heating 100 15.1.1 Testing the Complete System 100 15.1.2 Testing the Heating Element 100 15.1.3 Thermostatic Switch 101 15.
Introduction This service manual contains detailed descriptions of all the repair and servicing procedures specific to this power tool. You should make use of the illustrated parts lists while carrying out repair work. They show the installed positions of the individual components and assemblies. Refer to the latest edition of the relevant parts list to check the part numbers of any replacement parts.
Versions with Quick Chain Tensioner Engage the bar mounting studs in the outer bores in the mounting plate and secure the saw in position with the nuts (arrows). The chain sprocket cover and cutting attachment have to be removed before mounting the saw to the assembly stand – pull the hand guard toward the handlebar. 165RA468 TG 165RA000 TG 1 There is only one bar stud on these versions. It is pushed through the upper hole (arrow) in the mounting plate and secured with the nut (1).
2. Safety Precautions If the power tool is started up in the course of repairs or maintenance work, observe all local and countryspecific safety regulations as well as the safety precautions and warnings in the instruction manual. Gasoline is an extremely flammable fuel and can be explosive in certain conditions. Always wear suitable protective gloves for operations in which components are heated for assembly or disassembly. Improper handling may result in burns or other serious injuries.
3. Specifications 3.1 Engine Displacement: Bore: Stroke: Engine power to ISO 7293: Maximum permissible engine speed (with bar and chain): Versions with catalytic converter Maximum permissible engine speed (with bar and chain): Idle speed: Clutch: Clutch engages at: Crankcase leakage test at gauge pressure: under vacuum: 3.2 MS 240 MS 260, MS 260 C 41.6 cm3 42 mm 30 mm 2.1 kW (2.85 bhp) at 9500 rpm 50.2 cm3 44.7 mm 32 mm 2.6 kW (3.
3.5 Tightening Torquese DG and P (Plastoform) screws are used in polymer and light metal components. These screws form a permanent thread when they are installed for the first time. They can be removed and installed as often as necessary without impairing the strength of the screwed assembly, providing the specified tightening torque is observed. For this reason it is essential to use a torque wrench.
Fastener Thread size For component Torque Nm Remarks Screw Nut Screw Screw Screw M 5x12 M 8x1 M 4x8 M 4x16 M 3x20 M 5x8.5 M5 M 5x20 M 14x1.25 M 5x20 Muffler/crankcase/cylinder (MS 240) Flywheel Side plate/crankcase Side plate/crankcase (quick chain tensioner) Clamp/manifold Stud/cylinder Carburetor Cylinder/crankcase Spark plug Ignition module/crankcase (microencapsulated) 10.0 33.0 3.0 3.0 0.5 1.4 3.5 11.0 25.0 7.
4. Troubleshooting 4.
4.
4.3 Chain Lubrication In the event of trouble with the chain lubrication system, check and rectify other sources of faults before disassembling the oil pump. .
4.4 Rewind Starter Condition Cause Remedy Starter rope broken Rope pulled out too vigorously as far as stop or over edge, i.e.
4.5 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. Condition Cause Remedy Engine runs roughly, misfires, temporary loss of power Spark plug boot is loose Press boot firmly onto spark plug and fit new spring if necessary Spark plug sooted, smeared with oil Clean the spark plug or replace if necessary.
Condition Cause Remedy No spark Spark plug faulty Install new spark plug Faulty insulation or short in short circuit wire Check short circuit wire for short circuit to ground Break in ignition lead or insulation damaged Check ignition lead and replace if necessary Ignition module faulty Install new ignition module 14 MS 240, MS 260, MS 260 C
4.
Condition Cause Remedy Engine will not idle, idle speed too high Throttle shutter opened too wide by idle speed screw LA Reset idle speed screw LA correctly Oil seals/crankcase leaking Seal or replace oil seals/crankcase Idle jet bores or ports blocked Clean the carburetor Setting of low speed screw too rich or too lean Reset low speed screw L correctly Setting of idle speed screw LA incorrect – throttle shutter completely closed Reset idle speed screw LA correctly Tank vent faulty Replace ta
Condition Cause Remedy Engine speed drops quickly under load – low power Air filter dirty Clean air filter or replace if necessary Throttle shutter not opened fully Check throttle cable and rod Tank vent faulty Replace tank vent Fuel pickup body dirty Install new pickup body Fuel strainer dirty Clean fuel strainer in carburetor, replace if necessary Leak on fuel hose from tank to carburetor Seal connections or install new fuel hose Setting of high speed screw H too rich Check basic carburet
4.
5. Cutting Attachment When installing the adjusting wheel, make sure its teeth point inboard. 3 – Reassemble in the reverse sequence. 1 165RA469 TG 2 165RA002 TG 1 Wear gloves to protect your hands from injury. : Carefully pry the wing nut (1) out of the sprocket cover (arrow). : Unscrew the hex nuts (1). – Check the wing nut (1) and replace if necessary 5.1 Chain Catcher – Remove the sprocket cover and cutting attachment, b 5 : Remove the chain sprocket cover (2).
6. Clutch – Troubleshooting, b 4.1 1 1 – Remove the sprocket cover and cutting attachment, b 5 165RA011 TG 165RA014 TG – Remove the clutch drum, b 6.1 1 : Push the locking strip (1) 0000 893 5903 into the cylinder so that "OBEN-TOP" is visible. – Pull the clutch shoes off the carrier. 165RA009 TG : Remove the retainers (1). 1 – Remove the air filter, b 14.1 : Pull boot (1) off the spark plug. 165RA015 TG 165RA012 TG – Remove the shroud, b 8.4 : Unscrew the clutch (1).
1 2 : Fit the clutch shoes (2) over the arms (2). : Check the clutch – all springs (arrows) must be properly attached. 165RA023 TG 165RA017 TG 165RA020 TG 1 : Screw the clutch (1) on to the crankshaft stub and tighten down the hexagon (arrow) firmly – lefthand thread. – Tightening torques, b 3.5 TOP 1 – Reassemble all other parts in the reverse sequence. 165RA021 TG 165RA018 TG : Clamp the clutch in a vise (arrow). – Remove the locking strip from the cylinder.
6.1 Clutch Drum 165RA411 TG 165RA024 TG 1 : Pull off the needle cage (1). 2 1 165RA415 TG 1 The notch (arrow) in the clutch drum must engage the worm gear's driver (1). – Remove the sprocket cover and cutting attachment, b 5 – Clean the needle cage (1) and crankshaft stub, b 17 : Pull the hand guard (1) towards the handlebar. – Lubricate the needle cage (1) and crankshaft stub, b 17 Use the mark (2) for orientation.
Chain Brake 7.1 Checking Operation 7.2 Removing and Installing the Brake Band 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. – Start the engine. – With the chain brake activated (locked), open the throttle wide for a brief period (max. 3 seconds) – the chain must not rotate.
: Pry the brake band (1) out of its seat (arrow). – Remove the brake band (1). : Hold the brake band (1) sideways, attach it to the brake lever (arrow) and then swing it in the direction of its seat. 165RA040 TG 1 165RA044 TG 1 165RA040 TG 1 : Push the brake band (1) into its guide (arrow) as far as stop. 1 Do not over-stretch the brake band. 1 : Position the brake band (1) it the guide (arrow) first. : Turn the brake band (1) to one side and disconnect it from the brake lever (arrow).
7.3 Brake Lever 1 : Remove the E-clip (arrow). – Inspect the pivot pins and replace if necessary, b 7.5 – Troubleshooting, b 4.2 – Push the hand guard towards the guide bar. – Inspect the cam lever and replace if necessary, b 7.4 1 The brake spring (1) is now relaxed. 2 165RA050 TG – Remove the brake band, b 7.2 : Use the assembly tool 117 890 0900 to disconnect the brake spring (1) from the anchor pin (arrow). – Disconnect the brake spring (1) from the brake lever.
1 165RA054 TG 165RA057 TG 165RA059 TG 2 : Lift the bearing boss of the hand guard and the brake lever a little and position them over the pivot pins (arrows). : The turns of brake spring must be tightly against one another in the relaxed condition. If this is not the case, replace the brake spring. : Use the assembly tool (2) 1117 890 0900 to attach the brake spring (1) to the anchor pin (arrow). Check the correct position of the protective hose – it must be centered in the spring.
7.5 1 1 Pins : Remove the E-clip (arrow). 165RA064 TG 165RA061 TG The anchor pins secure the springs. Worn pins must be replaced – the springs may otherwise become detached and pop out. All parts have been removed from the pins in the following illustrations for greater clarity. : Fit the E-clip (1). – Pull the cam lever (1) off the pivot pin. 2 165RA066 TG 1 – Check the cam lever (1) and spring (2) and replace if necessary.
7.6 a 4 3 5 a 1 2 165RA069 TG b : Carefully tap home the pins to obtain the following dimensions: Pin (1) a = 4.3 – 4.7 mm Pin (2) b =. 3.0 – 3.4 mm 165RA378 TG 165RA068 TG : Drive home the pins (1 and 2) as shown in the illustrations. b – Remove the sprocket cover and cutting attachment, b 5 – Troubleshooting, b 4.2 c 1 Side Chain Tensioner 2 : Carefully tap home the pins to obtain the following dimensions: Pin (3) a = 4.3 – 4.7 mm Pin (4) b = 3.0 – 3.4 mm Pin (5) = 3.0 – 3.
7.6.1 Front Chain Tensioner 2 3 1 – Troubleshooting, b 4.2 4 165RA461 TG 6 5 1 – Remove the side plate, b 7.2 3 : Inspect the thrust pad (1), adjusting screw (2), tensioner slide (3), cover plate (4), spur gear (5) and O-ring (6) and replace as necessary. 165RA463 TG 2 – Remove the sprocket cover and cutting attachment, b 5 : Pull off the thrust pad (1) and unscrew the adjusting screw (2) from the tensioner slide (3). – Check the individual parts and replace if necessary.
1 Versions with Quick Chain Tensioner – Remove the sprocket cover and cutting attachment, b 5 – Remove the side plate, b 7.6 1 – Remove the sprocket cover and cutting attachment, b 5 – Remove the side plate, b 7.6 : Push stud puller 5910 893 0501 (1) over the collar stud (arrow) as far as it will go and unscrew the stud counterclockwise. : Before installing, coat threads (arrow) of collar studs with Loctite, b 17 – Fit collar studs and tighten them down firmly. – Tightening torques, b 3.
Engine 8.1 Muffler / Spark Arresting Screen 2 1 Always check and, if necessary, repair the fuel system, carburetor, air filter and ignition system before looking for faults on the engine. 1 165RA086 TG 165RA457 TG 8. – Troubleshooting, b 4 : Remove the heat shield (1), if fitted. 1 : Check the reflector foil (1), if fitted, and replace if necessary 165RA084 TG : Remove the gasket (2). Spark arresting screen (if fitted) 1 : Take out the screws (arrows).
1 2 2 1 : Place the heat shield (1) in position (if fitted) and use the indentations (arrows) to line it up on the sealing face of the cylinder exhaust port. : Insert screws (arrows) and tighten them down firmly. : Line up the screws (arrows) and check the position of the gasket. – Tightening torques, b 3.5 : Insert screws (2) to hold the muffler in position. 8.
Preparations 1 2 1 – Remove the shroud, b 8.4 – Set the piston to top dead center. This can be checked through the spark plug hole. – Remove the decompression valve, b 8.9 2 165RA099 TG 165RA474 TG 1 : Fit the sealing plate (1) 0000 855 8106 between the cylinder exhaust port and heat shield (if fitted) and tighten down the screws moderately. 1 165RA475 TG 8.2.1 – Pin (1) must be in the test flange 1128 850 4200 – it seals the impulse hose. : Make sure that the pin (1) is in hole "2" (arrow).
Vacuum Test Oil seals tend to fail when subjected to a vacuum, i.e. the sealing lip lifts away from the crankshaft during the piston's induction stroke because there is no internal counterpressure. A test can be carried out with pump 0000 850 1300 to detect this kind of fault. 1 If the vacuum reading remains constant, or rises to no more than 0.3 bar within 20 seconds, it can be assumed that the oil seals are in good condition.
Oil Seals – Clamp the puller arms. It is not necessary to disassemble the engine to replace the oil seals. – Pull out the oil seal. Take care not to damage the crankshaft stub. Ignition side – Remove the fan housing, b 10.2 – Clean the sealing face with a little standard solvent-based degreasant containing no chlorinated or halogenated hydrocarbons. – Remove the flywheel, b 9.5 – Remove the generator, b 15.
– Slip the oil seal (2), open side facing the crankcase, over the installing sleeve. 1 8.4 Removing and Installing the Shroud 165RA111 TG – Remove the installing sleeve (1). 2 165RA115 TG – Free off the oil seal in its seat by tapping it with a suitable tube or a punch. 165RA113 TG 1 : Apply puller (1) 5910 890 4400 with No. 3.1 jaws 0000 893 3706. : Use press sleeve (2) 1120 893 2400 to install the oil seal (1). – Clamp the puller arms. 2 1 : Unscrew the slotted nut (arrow).
Versions with decompression valve Cylinder Before removing the piston, decide whether or not the crankshaft has to be removed as well. 1 1 165RA008 TG 165RA005 TG 2 8.5 : Pull the insulator (1) off the slotted nut (2). – Check the individual parts and replace if necessary. : Bond the new reflector foil in position along the ribs (arrows). – Reassemble in the reverse sequence.
Always use a new cylinder gasket when re-installing the cylinder. 1 1 : Carefully lift the cylinder (1) away. 165RA032 TG : Pull off the stop buffer (1). 165RA495 TG 165RA116 TG 1 Do not use pointed or sharp-edged tools for this job. – Line up the cylinder gasket (1) so that the tabs (arrow) point toward the carburetor and cutting attachment. : Place the cylinder gasket (1) in position. 165RA387 TG 1 1 165RA030 TG : Pull the impulse hose (1) off the nipple (arrow).
: Tighten the screw until the gap "a" between the two ends of the hose clamp is about 5 to 6 mm. 1 165RA074 TG 165RA034 TG 1 : Line up the manifold (1) – the tab must be pisitioned as shown in the illustration (arrow). 165RA072 TG – Push the manifold (1) on to the intake stub. : Inspect and clean the sealing face (arrow) and remove any gasket residue. 165RA071 TG Apply the clamping strap (1) so that the piston rings do not project beyond the cylinder wall.
– On versions with handle heating, remove the generator, b 15.7 1 – Drain the fuel and oil tanks, b 1 – Remove the tank housing, b 14.8.3 – Lift the tank housing a little. : Push the impulse hose (1) on to the nipple (arrow). 165RA027 TG – Reassemble all other parts in the reverse sequence. 8.6 Crankshaft 8.6.1 Removing and Installing Use the tools in the service tool set 5910 007 2200 for removing and installing.
Versions with Quick Chain Tensioner Removing – ignition side 165RA117 TG Use the tools in the service tool set 5910 007 2200 for removing and installing. 2 1 165RA078 TG 16 1 165RA121 TG – Unscrew the spindle (1) of service tool 5910 890 2220 until the drilled plate (2) butts against the crankcase – left-hand thread. : Turn the spindle (2) clockwise until the crankshaft stub is pushed out of the ball bearing. : The tensioner slide (1) must butt against the thrust pad (arrow).
1 1 – Check the two halves of the crankcase and ball bearings and replace if necessary, b 8.6.2 Before installing, clean the crankshaft with a standard commercial, solvent-based degreasant containing no chlorinated or halogenated hydrocarbons. Installing – ignition side Take care not to damage the crankshaft stub. Inspect and clean the sealing faces on the ignition side of the crankcase (including the cylinder sealing face) – the sealing faces must not be damaged in any way.
Installing – clutch side 1 Take care not to damage the crankshaft stub. 165RA126 TG 165RA128 TG 2 : Position the screw sleeve (2) on the crankshaft thread and screw it into place. The crankshaft turns when it is being pulled into place with the service tool. Therefore, make sure the small end of the connecting rod always points upward to the cylinder.
– Screw the spindle (left-hand thread) fully into the service tool 5910 890 2205. : Screw the screw sleeve (1) 5910 893 2409 omto the spindle of service tool 5910 890 2205 as far as stop (left-hand thread). – Heat the inner bearing race to about 150°C (300°F). : Turn the spindle counterclockwise until the crankcase locates against the guide sleeves. : Push the crankcase fully home. – Coat straight stub of crankshaft with oil.
8.6.2 2 Each half of the crankcase can be replaced separately if it is damaged. 165RA117 TG 165RA075 TG 1 : Use a 4 mm dia. drift to drive home the dowel pin at the chain tensioner side until the pin is flush with the hole at the other side.4 m : Fit the washer (1) and ring (2). – Check and install the piston, b 8.7.2 – Check and install the cylinder, b 8.5 – Reassemble all other parts in the reverse sequence.
: Use a suitable punch to carefully drive out the oil seal. 165RA142 TG 165RA140 TG 165RA137 TG Ignition side of crankcase – Heat the area of the bearing seat to about 150 °C (300 °F). : Check and clean the crankcase or replace if necessary. – Position the ball bearing so that its open side (balls visible) face the outside of the crankcase. If this half of the crankcase is in order, install a new ball bearing. : Push the ball bearing home as far as stop.
8.7 Piston 8.7.1 Removal 1 2 – Heat the area of the bearing seat to about 150 °C (300 °F). – Position the ball bearing so that the centering ring (arrow) points toward the oil pump. 165RA147 TG 165RA480 TG Before removing the cylinder, decide whether or not the crankshaft has to be removed as well, b 8.6 – Remove the cylinder, b 8.
8.7.2 Installing 1 2 : Pull out the needle cage (1), check it and replace if necessary. – Lubricate the needle cage (1) with oil and push it into the connecting rod. – Lubricate the piston pin with oil. : Fit the piston pin (1) on the assembly drift (2) and slide it into the piston. 165RA154 TG 165RA151 TG 165RA149 TG 1 : Push the large slotted diameter of the sleeve over the magnet and snap ring. The inner pin must point towards the flat face of the tool's shank.
8.8 Piston Rings – Remove the piston, b 8.7.1 1 165RA158 TG 165RA156 TG Fit the snap ring (1) so that its gap (arrow) points either up or down. 165RA160 TG : Remove the sleeve and slip it onto the other end of the shank – the inner pin must point towards the flat face. – Remove the piston rings from the piston. Make sure the tool shank is held square on the piston pin axis. MS 240, MS 260, MS 260 C – Inspect the piston rings and replace if necessary, b 8.8 – Install the cylinder, b 8.
8.9 Decompression Valve 2 : Position the piston rings so that the radii at the ring gap meet at the fixing pin in the piston groove (arrows). : Check correct installed position of the piston rings (arrows). – Install the piston, b 8.7.2 165RA163 TG 165RA162 TG 1 – Remove the shroud, b 8.4 : Remove the cover (1). : Unscrew the decompression valve (2). 165RA164 TG – Reassemble all other parts in the reverse sequence. : Check the sealing cone (arrow) on the decompression valve for damage.
9. Ignition System Exercise extreme caution when troubleshooting and carrying out maintenance or repair work on the ignition system. The high voltages which occur can cause serious or fatal accidents. 9.2 Ignition Module 9.2.1 Removing and Installing – Remove the fan housing, b 10.2 1 The ignition module accommodates all the components required to control ignition timing.
1 1 : Pull boot (1) off the spark plug. – Disengage the connector. : Use a suitable punch to drive out the retainer (1). : Disconnect the short circuit wire (1) – do not pull it out of the retainer. 1 165RA174 TG 1 165RA171 TG 165RA009 TG 2 : Take out the screws (arrows). – Check the retainer and replace if necessary – Check the spark plug boot and ignition lead, and replace if necessary, b 9.4 – Remove the ground wire (2). 165RA169 TG – Reassemble in the reverse sequence.
: Rotate the flywheel until the magnet poles (arrows) are next to the ignition module. 165RA176 TG 1 : Fit the ignition module (1) and insert the screw (arrow) – do not tighten down yet. – Press the ignition module (1) against the setting gauge. 1 – Tighten down the screws firmly. – Tightening torques, b 3.5 – Remove the setting gauge. : Fit the ground wire (2) and insert the screw (arrow) – do not tighten down yet.
Testing the Ignition Module The engine may start and accelerate during the test. To test the ignition module, use either the ZAT 4 ignition system tester 5910 850 4503 or the ZAT 3 ignition system tester 5910 850 4520. The ignition test refers only to a spark test, not to ignition timing. 5 If a spark is visible, the ignition system is in order. 1 If no spark is visible in the window (2), check the ignition system with the aid of the troubleshooting chart, b 9.
9.4 Spark Plug Boot / Ignition Lead – Cut a new ignition lead to the specified length, see parts list. – Use a pointed tool to pierce the center of the new ignition lead’s insulation, about 15 mm from the end of the lead. 2 165RA481 TG 165RA190 TG 1 : Make sure the leg spring (arrow) locates properly inside the spark plug boot. 165RA188 TG – Remove the ignition module, b 9.2.1 : Pull the grommet (1) off the high voltge output (arrow).
9.5 Flywheel 1 – Remove the shroud, b 8.4 – Block the piston with the locking strip (1) 0000 893 5903, b 6 : Screw the puller (1) 1110 890 4500 clockwise into the flywheel as far as stop. : Use 24 mm open end wrench (3) to hold the puller steady and screw home the thrust bolt (2) until the flywheel is released from the crankshaft. 165RA194 TG 165RA192 TG – Remove the puller (1) 1110 890 4500 from the flywheel. : Unscrew the flywheel nut (arrow).
9.6 Short Circuit Wire 9.6.1 Testing 9.6.2 Removing and Installing – Remove the shroud, b 8.4 165RA200 TG – Remove the fan housing, b 10.2 – Remove the carburetor, b 14.2 The ground and short circuit wires are combined in a wiring harness. – Remove the fan housing, b 10.2 3 : Disconnect the short circuit wire (1). – Set the switch shaft to "0". The resistance measured must be about 0 Ω. If it is much higher, the reason is a break and the wire has to be replaced, b 9.6.2.
A faulty ground wire may impair or prevent operation of the short circuit wire, and the heating on versions with handle heating. 165RA207 TG 165RA202 TG Perform the contact and continuity test on the ground wire too. Versions with handle heating – Pull the wiring harness out of the opening (arrow). Make sure the retaining lug (arrow) locks the contact spring in position. 165RA205 TG 1 Check the additional wire (1) in the wiring harness and replace the wiring harness if necessary, b 15.8.
165RA212 TG 165RA210 TG 1 2 165RA214 TG 1 Start installation and connector of the short circuit wire at the ignition module. : Fit the grommet (arrow) in the opening and make sure it is properly seated. : Push connector (1) of ground wire (greem/yellow) into the contact spring as far as stop. : Connect the short circuit wire (1) and push it into the retainer (arrow). – Use STIHL press fluid to simplify assembly, b 17 : Push connectot (2) of short circuit wire into the switch shaft as far as stop.
9.6.3 Ground Wire 165RA209 TG A faulty ground wire may impair or prevent operation of the short circuit wire. – Check for contact and continuity and replace wiring harness if necessary, b 9.6.2 Versions with handle heating, b 15.8 Versions with handle heating 165RA497 TG : Push the pin and socket connector into the guides (arrows). 1 The ground wire is combined with the short circuit wire in a wiring harness.
9.7 Ignition System Troubleshooting Engine does not run Stop switch: – in position "F"? Check the spark plug: – Smeared with oil, black? – Sooted? – Electrode gap correct? – Contacts shorted? – Clean, readjust or replace the plug, b 9.3 Check the spark plug boot: – Firmly seated on plug (leg spring)? – Leg spring hook in center of ignition lead? – Boot damaged? – If necessary, install new spark plug boot and/ or leg spring, b 9.
1 Powerful spark? yes no Air gap: – Check ignition module/flywheel, – reset if necessary, b 9.2.1 Check the flywheel: – Have pole shoes turned blue? – Install new flywheel if necessary, b 9.5 Check short circuit wire: – Wire damaged? – Connectors firmly seated? – Check the short circuit wire for break and replace if necessary, b 9.6.1 Check the ignition lead: – Severe chafing? – Spark plug boot: Holes/cracks? – Resistance: spark plug boot to ground: spec. 1.
2 3 Check operation of switch shaft: – Short circuit wire chafed? – Function between contact spring and switch shaft contact: – Position "F" = no connection – Position "0" = connection – Install new short circuit wire if necessary, b 9.6.2 Powerful spark? yes no Install new ignition module, b 9.2.
General If the action of the starter rope becomes very stiff and the rope rewinds very slowly or not completely, it can 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.
– Pull out the rope with the starter grip and slowly release the rope rotor. : Position the spring clip (1) so that its loop engages the peg on the pawl and its curved end (arrow) is in the starter post’s groove. – Remove the starter rope or remaining rope from the rotor, b 10.5 165RA225 TG 165RA222 TG 1 1 The system will not be under tension if either the starter rope or rewind spring is broken. – Remove the spring clip and pawl, b 10.
10.5 Starter Rope / Grip Machines with ElastoStart Grip – Remove the fan housing and the segment, b 10.2 1 1 165RA230 TG The system will not be under tension if the starter rope is broken. – Remove remaining rope from the rope rotor and starter grip. : Use a suitable tool to pry the cap (1) out of the starter grip. Do not shorten the starter rope. – Remove the rope rotor, b 10.4 165RA233 TG – Relieve tension of rewind spring, b 10.4 : Thread the new starter rope (1) through the sleeve.
Machines with Standard Starter Grip – Install the rope rotor and tension the rewind spring, b 10.4 – Install the fan housing, b 10.2 1 165RA227 TG 165RA235 TG – Tightening torques, b 3.5 : Thread the starter rope (1) through the guide bushing (arrow). 10.6 1 – Pull the rope out of the starter grip. Tensioning the Rewind Spring 2 1 165RA228 TG 165RA236 TG 165RA238 TG : Tie one of the special knots shown in the end of the rope. : Thread the starter rope (1) through the side of the rope rotor.
10.7 2 Replacing the Rewind Spring – Troubleshooting, b 4.4 165RA237 TG 165RA241 TG 1 : Pull out the twisted rope (1) with the starter grip and straighten it out. The rewind spring is correctly tensioned when the starter grip sits firmly in the rope guide bushing (arrow) without drooping to one side. If this is not the case, tension the spring by one additional turn.
1 Check that the rewind spring (1) is properly seated and the anchor loop engages the lug (arrow). If the rewind spring has popped out, refit it in the fan housing as follows: : Fit the rewind spring (1) counterclockwise in the housing, starting from outside and working inwards. – Hold the spring windings so that they cannot pop out. a – Arrange the spring (1) in its original position. The position of the anchor loop cannot be changed after the rewind spring is fitted in the spring housing.
Servicing the AV System – Reassemble all other parts in the reverse sequence. Vibration-damping rubber buffers are used for the connection between the handlebar, tank housing and engine housing. Damaged rubber buffers (annular buffers) must always be replaced. Annular Buffer on Chain Catcher Always replace a damaged annular buffer. – Remove the sprocket cover and cutting attachment, b 5 11.2 1 165RA250 TG 11.1 – Tightening torques, b 3.
1 – Check the annular buffer (1) and replace if necessary 165RA258 TG : Pry out the annular buffer (1). 1 165RA254 TG 165RA486 TG 2 – Position the tank housing on the annular buffer – the holes must line up. : Take out the screws (arrows) and remove the retaining plate (2). – Remove the annular buffer (1). : Insert screw (arrow) and tighten it down firmly. – Check the annular buffer (1) and replace if necessary – Push the plug into the annular buffer as far as stop.
11.5 Handlebar – Remove the sprocket cover and cutting attachment, b 5 1 – Fit the washer (1). : Insert screw (arrow) and tighten it down firmly. – Reassemble all other parts in the reverse sequence. Lower the tank housing a little – check that the impulse is pushed fully onto the connector on the crankcase. : Ease the stop buffer (1) out of the bore. – Check the stop buffer (1) and replace if necessary 165RA262 TG – Position the tank housing on the annular buffer – the holes must line up.
1 165RA266 TG 165RA264 TG 1 – Take out the annular buffer/tank housing mounting screws. Annular buffer at ignition side, b 11.3. Annular buffer at clutch side, b 11.2 – Remove the interlock lever, b 12.2 – Remove the switch shaft, b 12.1.1 : Position the handlebar (1) in its seat on the side of the machine (arrow) and insert the screws. – Remove the handlebar (1), check it and replace if necessary. – Check that the handlebar is properly seated and then tighten down all four screws firmly.
Removing the Handlebar – Push the insulating tube (1) in the directon of the heating element. 165RA273 TG 165RA268 TG 1 165RA270 TG 1 : Pull the wiring harness out of the hole (arrow) in the housing in the direction of the cylinder. : Place the handlebar in position and continue pulling the wiring harness (1) through the hole until it is snugly seated in the recess (arrow). : Separate the pin and socket connector (arrow).
1 1 2 2 165RA280 TG : Push the wire (1) through the insulating tube (2). 165RA278 TG 165RA276 TG 1 : Push the wires with the insulating tube (1) into the guide. – The ground wire ring terminal (2) must be in position on the heater switch. The wires and insulating tube (1) must not project – risk of chafing on switch shaft or throttle rod. : Position the handlebar (1) so that the heater switch engages the opening (arrow). – Secure the handlebar, b 11.
Switch Shaft 12.1.1 Removing and Installing 2 1 The following positions can be selected with the switch shaft: – Remove the air filter, b 14.1 – Position 0 = engine off – ignition is switched off – Remove the handle molding, b 12.2 – Position F = normal run position – engine runs or may start in this position 1 2 165RA284 TG 12.1 165RA282 TG Control Levers 165RA281 TG 12. : Pry the switch shaft (1) out of its mount (arrow).
12.2 2 Throttle Trigger/Interlock Lever 1 2 – Line up the switch shaft – the lever (1) must locate in the guide (arrow). – The contact spring (1) must butt against the switch shaft's (2) guide. : Press the switch shaft into the mount (2) until it snaps into position. : Move switch shaft to "0" – contact between the short circuit wire and contact spring (arrow) must be made. 165RA289 TG 165RA288 TG 165RA286 TG 1 – Remove the air filter, b 14.1 : Take out the screw (arrow).
1 3 1 : Ease the interlock lever (1) out of its mounts (arrows). – Disconnect the torsion spring and remove the interlock lever. 165RA297 TG 2 165RA294 TG 165RA291 TG 1 – Check the interlock lever (1), trottle trigger (2) and torsion spring (1) and replace if necessary : Fit the throttle trigger (1) in the rear handle so that its lug is behind the arm on the switch shaft (arrow). Versions with handle heating 1 1 : Use a drift (2) to drive out the pin (1).
1 When installing the interlock lever, make sure its stop (1) engages the recess in the throttle trigger. : Attach the throttle rod (1) to the trigger (2). : Attach the torsion spring (2) to the interlock lever (arrow). Versions with handle heating 1 165RA302 TG 2 165RA335 TG 1 165RA299 TG 2 : Engage tab of handle molding (1) in the opening (arrow).
Chain Lubrication 13.1 Pickup Body 13.2 Impurities gradually clog the fine pores of the filter with minute particles of dirt. This prevents the oil pump from supplying sufficient oil. In the event of problems with the oil supply system, first check the oil tank and the pickup body. Clean the oil tank if necessary, b 1 Oil Suction Hose 1 – Remove the sprocket cover and cutting attachment, b 5 – Remove the clutch, b 6 165RA305 TG 13. – Remove the brake band, b 7.2 – Troubleshooting, b 4.
13.3 Oil Delivery Hose 13.4 Non-Adjustable Oil Pump 165RA307 TG : Fit the new oil delivery hose (1) through the bore (arrow) from outside. – Take out the screws. : Remove the oil pump (1) and disconnect the oil delivery hose (arrow). a 165RA311 TG 1 1 165RA309 TG – Remove the worm, b 13.5 The procedures for removing and installing the non-adjustable oil pump are the same as those for the adjustable oil pump, b 13.
13.5 Adjustable Oil Pump 2 40 710 0 11 21 6 – Troubleshooting, b 4.3 – Remove the clutch, b 6 165RA354 TG 1 165RA315 TG – Remove the brake band, b 7.2 : Check the worm (1) and driver (2) and replace if necessary If a new oil pump is installed, worms with the number 1121 640 7100 (arrow) must also be replaced. Worms with the number 1121 640 7102 may be used with the new pump. (The numbers shown are not part numbers.) – Remove the side plate, b 7.
13.6 1 – Line up the oil pump so that the intake stub points toward the oil suction hose (arrow). 165RA321 TG 165RA318 TG 1 : Push the worm (1) into the oil pump. Valve A valve is installed in the tank wall to keep internal tank pressure equal to atmospheric pressure. The valve must be replaced if it is faulty. – Remove the sprocket cover and cutting attachment, b 5 – Open the oil tank cap and drain the oil tank.
165RA324 TG Check correct installed position. 165RA325 TG : Insert the valve in the housing bore (arrow). 219RA479 TG : Use a 6 mm drift to carefully drive in the new valve from outside – note installed depth. : Installed depth of new valve: a = about 2 - 3 mm – Reassemble all other parts in the reverse sequence.
Fuel System 14.1 Air Filter 14.2 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. – See also Troubleshooting, b 4.5, b 4.6 Removing and Installing the Carburetor – Remove the air filter, b 14.1 – Open the fuel tank cap and drain the fuel tank. 165RA327 TG 14. – Collect the fuel in a clean container, b 1 Pull off the carburetor only when the tank cap is open.
Versions with handle and carburetor heating 1 – Fit the handle molding, b 12.2 – Check operation. 2 – Reassemble all other parts in the reverse sequence. 1 – Tightening torques, b 3.5 165RA333 TG 165RA100 TG 2 Check that the sleeve (2) and washer (1) are in place. The throttle rod must be attached to the carburetor. : Fit the heating element (1) and heating plate (2). – Fit the nuts and tighten them down firmly. 14.
3. Pump diaphragm or gasket damaged, replace if necessary, b 14.4.3 165RA338 TG 1 1. The inlet needle is not sealing (foreign matter in valve seat, sealing cone of inlet needle is damaged or inlet control lever is sticking). Remove to clean, b 14.4.1 2. Metering diaphragm or gasket damaged, replace if necessary, b 14.4 2 – Push the pressure hose of pump 0000 850 1300 on to the nipple.
Versions with handle and carburetor heating : Remove the end cover (1). 2 3 165RA076 TG – Note installed positions of metering diaphragm (2) and gasket (1). If the gasket and diaphragm are stuck to the carburetor, remove them very carefully. 1 2 : Place the gasket (1) and metering diaphragm (2) on the pegs (arrows) and check that the tabs (3) are at the same side as the adjusting screws.
14.4.1 Inlet Needle Make sure the spring locates on the control lever’s nipple. – Remove the metering diaphragm, b 14.4 165RA348 TG 165RA345 TG – Press the inlet control lever down and secure it with the screw. : If there is an annular indentation (arrow) on the sealing cone of the inlet needle, fit a new inlet needle. – Check that inlet control lever moves freely. – Install the metering diaphragm, b 14.4 14.4.2 Fixed Jet 1 : Take out the screw (arrow).
14.4.3 Pump Diaphragm 2 1 3 165RA358 TG 165RA355 TG 2 : Carefully separate the pump diaphragm (1) and gasket (2). – Remove the carburetor, b 14.2 The diaphragm material is subjected to continuous alternating stresses and eventually shows signs of fatigue, i.e. the diaphragm distorts and swells and has to be replaced. : Take out the screw (arrow). 165RA360 TG 1 : Fit the gasket (1) so that the tab (2) is opposite the idle speed screw (3) and is held in position by the pegs (arrows).
– Align the end cover (1) so that its pegs engage the holes in the carburetor body. 14.4.5 Adjusting Screws 2 : Pull off the grommets (1 and 2). 1 3 2 165RA363 TG : Insert screw and tighten it down firmly. – Reassemble all other parts in the reverse sequence. 1 Grommets have been removed for the sake of clarity.
High speed screw 14.5 Adjusting the Carburetor 14.5.1 Basic Setting 2 1 : Inspect the tip (arrow) for damage or wear and replace the screw (H) if necessary. – Continue with installing limiter cap. – Check chain tension and adjust if necessary. Pre-installing limiter cap – Inspect the spark arresting screen (if fitted) and clean or replace if necessary. b 8.1 – Check the air filter and clean or replace if necessary, b 14.1 1 : Pull out the limiter cap (1). – Take out the high speed screw (H).
On machines with a catalytic converter, make sure the engine speeds do not drop below the minimums specified, b 3.1. 1 0 – Troubleshooting, b 4.6 – Check chain tension and readjust if necessary (see MS 240, 260 instruction manual). 2 14 4 165RA373 TG 8 10 : Push the screwdriver (1) 5910 890 2304 through the opening (arrow) and the preinstalled limiter cap and into the high speed screw – the low speed screw does not have a limiter cap and can be adjusted with screwdriver 5910 890 2305.
– Turn the idle speed screw (LA) counterclockwise until the chain stops running, then turn it back one quarter turn. Erratic idling behavior, poor acceleration (although standard setting is correct) 14.6.1 Removing and Installing the Intake Manifold If the adjustments produce no improvement, see the troubleshooting charts for the ignition system, carburetor and engine, b 4.5, b 4.6 and b 4.7 14.6 A damaged intake manifold can result in engine running problems. – Troubleshooting, b 4.6 or b 4.
1 : Press the tank housing (1) down slightly and push the manifold flange (2) out of the tank housing in the direction of the cylinder. : Push the impulse hose (1) on to the connector (arrow). : Pull the ends of the string with the manifold flange through the opening. This method ensures that the manifold flange is pulled into place without any damage. 1 – Pull the impulse hose off the connector. 165RA383 TG 165RA381 TG 2 165RA379 TG 1 1 165RA382 TG 1 : Loosen and remove the hose clamp (1).
14.6.2 Impulse Hose A damaged impulse hose can result in engine running problems. – Remove the carburetor, b 14.2 : Pull the impulse hose (1) out of the tank housing in the direction of the throttle trigger. – Check the impulse hose (1) and replace if necessary – Take out the annular buffer/tank housing mounting screws. Annular buffer at ignition side, b 11.3. Annular buffer at clutch side, b 11.2 – Reassemble all other parts in the reverse sequence. Tank Vent 14.7.
Equalization of pressure takes place via the tank vent. There must be no buildup of vacuum in the tank. – Clean the area around the tank vent. 14.7.2 Removing and Installing 1 : Pull the fuel hose (1) off the stub (arrow). – If necessary, install a new tank vent or tank, b 14.7 or b 14.8.3 165RA394 TG 165RA390 TG 1 Pressure test 1 2 – Remove the carburetor box cover, b 9.2.1 1 : Push the nipple (1) 0000 855 9200 into the fuel hose (arrow).
In the event of problems with the fuel supply system, always check the fuel tank and the pickup body first. – Troubleshooting, b 4.6 or b 4.7 1 165RA395 TG Any impurities mixed with the fuel are retained by the pickup body (filter). The fine pores of the filter eventually become clogged with minute particles of dirt. This restricts the passage of fuel and results in fuel starvation. – Open the tank cap. 165RA397 TG 14.8 Fuel Intake 14.8.1 Pickup Body : Check the fuel hose and replace if necessary.
– Push the manifold flange out of the tank housing and pull the impulse hose off the connector, b 14.6.2 1 1 : Use hook 5910 893 8800 to pull the fuel hose (1) out of the fuel tank. – Remove the short circuit wire, b 9.6.2 2 – Remove the wiring harness, b 15.8 : Fit the front end (2) of the tank housing (1) between the two halves of the crankcase and line it up with annular buffer bores. – Remove the handle heating system, b 15.3 – Insert the annular buffer/chain catcher mounting screw.
15. Heating System 15.1 Carburetor Heating 15.1.2 Testing the Heating Element Idling problems with a hot engine are also an indication of a fault in the heating element or thermostatic switch. 15.1.1 Testing the Complete System The generator and heating element are checked in the following test which should be performed at an ambient temperature of at least + 20 °C (68 °F). If the temperature is lower than + 13 °C (55 °F), the thermostatic switch may close and produce false readings.
1 : Push the pin and socket connectors (1) into the guides (arrows). 165RA328 TG : Clip one test lead to the heating element and the other to the terminal pin. 165RA408 TG 219RA561 TG 15.1.3 Thermostatic Switch : Remove connector (arrow) from the contact spring. If the heating element is in good condition the ohmmeter will indicate a value of about 8 Ω in measuring range "Ω". – Remove the carburetor, b 14.2 – Check operation, b 15.
The thermostatic switch may open or close within the tolerance range between +13°C and +6°C, i.e. the switch must open at + 6°C and close at 13°C at the latest in each case. – Clip one test lead to the contact spring and the other to the flag terminal. 165RA416 TG Testing the thermostatic switch 165RA414 TG 165RA467 TG 1 : Position the retainer (1) so that its tab engages the lug (arrow). : Position the wire in the guide (arrow) between the tank housing and carburetor. 2 – Insert the screws.
15.2 Carburetor Heating System Troubleshooting Chart – Measure resistance of heating element at temperature = +20°C (68°F) no Resistance approx. 8 Ω? – Replace heating element, b 15.1 yes – Check thermostatic switch on basis of tolerance range of + 13°C (55 °F) to + 6°C (43 °F) Does thermostatic switch close between + 13°C (55 °F) and + 6 °C (43 °F), but no later than + 6 °C (43 °F)? no – Replace thermostatic switch, b 15.1.3 no – Replace thermostatic switch, b 15.1.
15.3 Handle Heating System If the ohmmeter shows a very low value, there is a short circuit in one of the components. 15.3.1 Troubleshooting The entire handle heating system is maintenance-free and subject to practically no wear. Faults in the generator, heating elements and wiring are generally caused by mechanical damage. There are two reasons for failures in the heating system: 1. A break in the circuit due to a faulty wire or component. 165RA490 TG 1 : Set the heater switch (1) to "F".
– Remove the sprocket cover and cutting attachment, b 5 2 1 – Pull the heater switch (1) out a little. : Position the heater switch with the groove (arrow) facing up. : Pull the grommet (2) off the heater switch (1). – Push the heater switch into the tank housing recess. – Fit the ground wire on the heater switch, b 15.4.1 – Secure the handlebar, b 11.5 165RA426 TG 165RA352 TG 165RA422 TG 1 : Take out the screw (arrow). – Remove the ground wire (1).
: Push the small ring terminal of the new ground wire through the opening (arrow). 165RA431 TG 165RA406 TG 165RA428 TG 1 : Push the ground wire into its guide (arrow) as far as stop. : Pull out the pressure pad (1). – Secure the handlebar, b 11.5 – Reassemble all other parts in the reverse sequence. – Insert screw and tighten it down firmly. – Tightening torques, b 3.5 15.
1 – Remove the backing from the new element. : The new heating element (1) must be bonded in position so that its wings are in line with the edges (arrows) of the handle and it lies perfectly flat. 165RA295 TG 165RA434 TG 165RA433 TG 1 : Fit the pressure pad (1) in the handle so that the heating element is completely covered and only the tab (arrow) projects. 1 The wires must be in the guide (arrow). – When fitting the handle molding, check that the wires are not pinched, b 15.
Removing and Installing the Heating Element in the Handlebar 15.7 Removing and Installing the Generator 1 165RA439 TG The heating element in the handlebar (front handle) is not replaceable. A new handlebar must be fitted if the heating element is faulty. 165RA437 TG – Remove the handle molding, b 12.2 – Remove the heater switch, b 15.4 : Take out the screws (arrows). – Remove the ignition module, b 9.2.1 – Expose and separate the wires for the handlebar, b 11.6 1 – Remove the flywheel, b 9.
– Use threadlocking adhesive, b 17. : Inspect the magnet ring (arrow) in the flywheel for cracks or other damage. If damage is found, replace the flywheel. 1 165RA447 TG – Tightening torques, b 3.5 : Push the generator wire and connector (1) into the guides (arrows) as far as stop. 2 1 165RA445 TG 165RA442 TG – Insert the screws through the holes (arrows) and tighten them down firmly. 1 – Remove the centering tool (1).
15.7.1 Handle Heating and Generator Troubleshooting Chart Start yes Do both handles warm up? no Heater switch on "F"? yes no Turn on the switch Measure resistance of individual heating elements with ohmmeter (On machines with carburetor heating, separate pin and socket connector to carburetor heating element), b 15.1 Check rear handle heating element. In good condition? Flat against handle housing? no yes Resistance of rear handle heating element about 1.
3 2 1 Test ground wire between crankcase and heater switch no Resistance between connector tags and crankcase about 0 Ω ? Install new ground wire, b 9.6.3 yes Expose and separate connectors of handlebar heating element, b 11.6 Test handlebar heating element Resistance about 6.4Ω? no Install new handlebar, b 11.6 yes Test heater switch (contact sleeve against switch housing) Closed: about 0Ω? Open: Circuit interrupted, b 15.4 no Install new heater switch, b 15.
15.7.2 Test Connections and Test Values – The pin and socket connections of the wires in the rear handle must be disconnected to test the individual components. Ohmmeter connection (use either test lead) Resistance Ω If faulty Lead 1 Lead 2 Spec. Actual Cause Remedy Switch Switch terminal 1) Switch housing < 0.5 - Switch faulty Replace switch Heating element in rear handle Connector on wire from heating element Connector on wire from heating element 1.6 1.5 - 2.
Component Generator Ohmmeter connection (use either test lead) Resistance Ω If faulty Lead 1 Lead 2 Spec. Actual Cause Connector on generator wire Ground 0.6 0.
15.8 Wiring Harness 1 – Remove the shroud, b 8.4 – Remove the ignition module, b 9.2.1 – Remove the handle molding, b 12.2 – Remove the switch shaft, b 12.1.1 1 165RA089 TG – Remove the carburetor, b 14.2 165RA269 TG 2 – Remove the short circuit wire, b 9.6.2 : Take the wire (1) with insulating tube (2) out of the guide (arrow). : Pull the connector (1) and wires out of the guides (arrows). – Pull the heating element/wiring harness wire (1) out of the insulating tube (2).
The wires and insulating tube (1) must not project – risk of chafing on switch shaft or throttle rod. 1 – Install the switch shaft, b 12.1.1 2 : Push the heating element/wiring harness wire (1) through the insulating tube (2). 165RA452 TG 165RA276 TG – Install the interlock lever, b 12.2 1 : Position the wire (1) behind the pin and socket connector (arrow). 1 – Install the short circuit wire, b 9.6.2 165RA407 TG 1 – Install the carburetor, b 14.
16. Special Servicing Tools No. Description Part No.
No. Description Part No.
17. Servicing Aids No. Description Part No.
MS 240, MS 260, MS 260 C 119
120 MS 240, MS 260, MS 260 C
englisch / english 0455 165 0123. M2,5. J8. Rei.
