Safety equipment ..........16 Repair instructions ..........24 Carburettor ............33 Fault tracing ............53 Husqvarna AB has a policy of continuous product development and therefore reserves the right to modify the design and appearance of products without prior notice. English –...
Index Index Muffl er 19 Bar bolt 52 Assembling the muffl er 19 Replacing the bar bolt 52 Dismantling the muffl er 19 Carburettor 33 Oil pump and screen 31 Assemble on the saw 40 Assembling the oil pump and screen 32 Assembly 38 Cleaning and inspection 31 Carburettor adjustment 41...
Page 5
Index Vibration damping system 43 Assembly 43 Cleaning and inspection 43 Dismantling 43 English –...
Page 6
Introduction and safety instructions 2 Introduction and safety instructions Contents General ...........................7 Security ...........................7 Target group ........................7 Changes ..........................7 Tools ..........................7 Structure .........................7 Numbering ........................7 General instructions ......................8 Special instructions ......................8 2.10 Symbols on the saw .......................9 2.11 Symbols in the Workshop Manual ..................9 –...
Workshop Manual. Usage is evident from respective sections. Some sections include a Description of the actual unit in order to increase the basic understanding. Always use Husqvarna’s original: • Spare parts 2.7 Numbering • Service tools Position references to components inside the fi...
Page 8
Introduction and safety instructions 2.8 General instructions 2.9 Special instructions The workshop where chain saw repairs are to be The fuel that is used in a chainsaw poses the fol- done must be equipped with safety equipment as lowing hazards: set out in local provisions.
Page 9
Introduction and safety instructions 2.10 Symbols on the saw 2.11 Symbols in the Workshop Manual The symbols below are embedded on the chain saw. This symbol warns of personal injury Choke Lever when the instructions are not followed Refuelling Stop button Screw for adjusting chain lubri- cation Filling with chain oil...
Page 13
Special tools Item Description Used for Order no. Clutch tool Centrifugal clutch 502 54 16-03 Piston stop Locking the crankshaft 504 91 06-05 Fuel fi lter hook Withdrawing the fuel fi lter 502 50 83-01 Allen key For M5 bolts 502 50 87-01 Allen key For M6 bolts...
Safety equipment 6 Safety equipment Contents Dismantling the chain brake ...................17 Assembling the chain brake ....................18 Dismantling the muffl er ....................19 Assembling the muffl er ....................19 Replacing the chain catcher ...................20 Dismantling the stop control ...................20 Resistance measurement - stop function ...............21 Assembling the choke/stop control .................21 Dismantling the throttle lock, throttle control and spring ..........22 6.10...
Safety equipment 6 Safety equipment 6.1 Dismantling the chain brake Release the brake by moving the front hand guard backward. Loosen the bar nuts and remove the clutch cover, chain and bar. (see fi gure 1) Fig 1 Carefully tighten the clutch housing in a vice. Release the brake by using the saw's front hand guard (A) as a tool.
Safety equipment 6.2 Chain brake – reassembly Bolt the elbow joint to the brake band (see fi gure 5) and tighten to a torque of 1–1.5 Nm. Locate the elbow joint and connected brake band in their recesses in the clutch cover. Lubricate the recess for the spring with grease.
Safety equipment Operating test: The engine must not be running during the test. Guide bar length Height 38cm/15" 50 cm/20" • Hold the chainsaw over a fi rm surface. The height of the guide bar above the surface is given in the table above. •...
Safety equipment 6.5 Chain catcher – replacement If the chain catcher is worn it must be replaced with a new one. Release the brake by pushing the kickback guard backwards. Undo the guide bar bolts and remove the clutch cover, chain and guide bar. Remove the chain catcher and replace it with a new one.
Safety equipment 6.7 Stop switch – resistance measurement Clean the mating surfaces and check the resis- tance as follows: Measure the resistance by connecting a multimeter to the ignition coil. NOTE! The switch must be in the “on” (A) position to give the correct reading. (see fi...
Safety equipment 6.9 Throttle lock, throttle trigger and return spring – removal Loosen the throttle cable on the carburettor, the fuel hose and suction hose to the fuel pump. Dismantle the tank unit from the engine unit by loosening the screws A and E (see fi gure 17) 2xA A Fig 17 Dismantle the handle insert (B) by loosening the...
Safety equipment Now loosen the spring. Cleaning and inspection • Clean and inspect all parts carefully. If there are any cracks or other defects replace the dama- ged parts with new ones. Always use original parts. Fig 21 • Check that the spring is not broken and has not lost its tension.
Repair instructions 7 Repair instructions Contents Dismantling the starter ....................25 Changing a broken or worn starter cord .................26 Tensioning the return spring ...................26 Changing a broken return spring ..................27 Assembling the starter unit .....................27 Testing the ignition module .....................27 Dismantling the ignition module and fl ywheel ..............28 Assembling the ignition module and fl...
Repair instructions 7 Repair instructions 7.1 Starter assembly – removal Undo the four bolts that fasten the starter assembly to the crankcase and lift off the starter assembly. (see fi gure 1) Fig 1 Pull out about 30 cm of the cord and fasten it in the notch in the pulley rim.
Repair instructions 7.2 Changing a broken or worn starter cord When the starter cord is worn and must be replaced, the tension on the return spring must be released. Pull the cord out about 30 cm and lift it into the notch on the outside of the starter pulley.
Repair instructions 7.4 Replacing a worn recoil spring WARNING! Make sure the recoil spring does not fl y out and cause injury. Wear eye protection.. Remove the bolt from the centre of the pulley and lift off the pulley and spring cassette. Replace the defective spring cassette with a new one.
Repair instructions 7.7 Ignition module/fl ywheel – removal Remove the cylinder cover. Disconnect the HT lead, remove the spark plug and fi t piston stop 502 54 15- 01. in its place. Take off the starter assembly, release the leads from the cable guide and remove it. (see fi...
Repair instructions 7.8 Ignition module and fl ywheel – refi tting Fit the fl ywheel on the crankshaft journal. Turn the fl ywheel so that the key lines up with the keyway in the shaft. Fit the nut on the shaft and tighten to a torque of 25-30 Nm.
Repair instructions 7.9 Centrifugal clutch – removal Remove the cylinder cover. Disengage the chain brake by pushing the kickback guard backwards. Undo the bar nut and remove the clutch cover, bar and chain. (see fi gure 13) Disconnect the HT lead. Remove the spark plug and fi...
Repair instructions 7.10 Centrifugal clutch – refi tting Insert the clutch springs in the shoes using circlip pliers. Screw the clutch (anti-clockwise) until it stops. Now tighten using tool 502 54 16-03 and a suitable socket wrench or combination spanner. Tightening torque min.
Repair instructions 7.12 Assembling the oil pump and screen 7.14 Assembling the intake system Fit the chain guide plate with tightening torque Assemble the carburettor fl ange and air fl ange 1–1.5 Nm. on the intake bellows. Now assemble the intake bellows and the partition on the cylinder using tool Fit the drive gear, needle bearing, clutch drum and 502 50 87-01.
Repair instructions 7.15 Carburettor WARNING! The fuel used in the chainsaw has the following hazardous properties: 1. The fl uid and its fumes are poisonous. 2. Can cause skin irritation. 3. Is highly infl ammable. Description The drawings accompanying this description do not correspond with the carburettor on the chainsaw.
Page 34
Repair instructions Function The carburettor operates differently in the following modes: • Cold start mode • Idling mode • Part throttle mode • Full throttle mode In the cold start mode (see fi gure) the choke valve (H) is fully closed. This increases the vacuum in the carburettor so that fuel is sucked more easily from all the diffuser jets (D, E and F).
Page 35
Repair instructions Dismantling the carburettor 1. Dismantle the cylinder cover and the air fi lter. 2. Loosen the bolts (A). 3. Loosen the fi lter holder from the rubber moun- tings (B). (see fi gure 29) Fig 29 4. Loosen the suction hose (C) and return hose (G) from the fuel pump.
Page 36
Repair instructions 8. Dismantle the cover (A) on the metering unit and carefully remove the control diaphragm (B) with gasket. 9. Dismantle the screw (F) and lift out the jet valve (E) with lever (D), shaft (G) and spring (H). 10.
Page 37
Repair instructions 5. That the tips of the high (N) and low jet screws Cleaning and inspection Clean all units in clean petrol. (P) are not damaged. (see fi gure 31) 6. That the intake manifold is undamaged. Use compressed air to dry the petrol on the com- 7.
Page 38
Repair instructions Assembly Maintain a high level of cleanliness when assem- bling the carburettor. The slightest contamination can result in running problems. 1. If the throttle and choke valves, together with levers and springs were removed, they should be refi tted. The spring is tensioned 1-2 turns. Lubricate the shaft bearings with light oil.
Page 39
Repair instructions Pressure testing the carburettor Pressure testing should be carried out with the car- burettor fully assembled. Testing should always be carried out after the carburettor has been repaired, but it can also be carried out as trouble shooting before dismantling the carburettor.
Page 40
Repair instructions Assemble on the saw 1. Assemble the fuel pump and suction hose on the carburettor. 2. Assemble the fuel hose. (F) 3. Position the carburettor. 4. Fit the return hose (G) on the fuel pump. 5. Fit the throttle cable. (E) (see fi...
Page 41
Repair instructions Carburettor adjustment Conditions during adjustment • The air fi lter should be clean and the cylinder cover fi tted when adjustments are made. Ad- justing the carburettor with a dirty air fi lter will give a too lean fuel mixture the next time the air fi...
Repair instructions 7.16 Tank unit WARNING! The fuel used in the chain saw has the following hazardous properties: The fl uid and its vapour are poisonous. Can cause skin irritation. Is highly infl ammable. Dismantling 1. Drain the fuel from the tank. 2.
Repair instructions 4. Pump 3 times. 5. After pumping the indicator should stop at max. 7 kPa. Assembly 1. If the throttle lock has been removed, this must be assembled before the tank unit and engine unit are assembled. 2. Lift the engine unit above the tank unit and in- sert the fuel hoses (in J), return hose (in H)and throttle cable (in G) in the bottom of the carbu- rettor compartment.
Repair instructions 7.19 Replacing the fuel fi lter NOTE! Do not use knurled pliers to disconnect or reconnect the fuel hose. This could dam- age the hose and lead to leakage or frac- ture. First remove the old fuel fi lter from the tank unit using special tool 502 50 83-01.
Repair instructions 7.22 Piston and cylinder – removal The fuel tank does not need to be removed when removing the cylinder. Remove: • cylinder cover • carburettor (see “Carburettor – removal”) • silencer • spark plug Undo the four cylinder bolts from the underside and lift the cylinder off carefully.
Page 46
Repair instructions Check the following: • The surface coating of the cylinder is not worn through, especially in the upper part of the cylinder. • The cylinder is free from score marks and areas of wear. • The piston is free from score marks. Small scratches can be polished out with fi...
Repair instructions Faults and causes Score marks on the piston (A) 1. Incorrect carburettor setting. Too high over- speed. 2. Too low octane fuel. 3. Too low or incorrect oil in the fuel. Carbon build-up (B) 1. Incorrect carburettor setting. Too low over- speed.
Page 48
Repair instructions Inlet manifold The intake system has two intakes. 1. The lower intake leads the fuel and air mixture from the carburettor to the cylinder. 2. The upper intake leads air to the cylinder. Assembling the intake system Assemble the carburettor fl ange (D) and air fl ange (C) on the intake bellows (A).
Repair instructions 7.24 Cylinder – pressure testing Remove: • cylinder cover • carburettor • spark plug Attach both the pressure testing covers. (see fi gure Loosen the screws on the muffl er and press the Fig 61 rubber sheet 502 54 11-02 between the muffl er and cylinder.
Repair instructions 7.27 Crankshaft complete – reassembly Fit the crankshaft complete in the crankcase. Refi t the following parts: • piston and cylinder* • handle system • hand guard • silencer* • carburettor* • centrifugal clutch* • starter assembly* • cylinder cover •...
Repair instructions 7.29 Replacing the bar bolt Replacing the front bar guide. Drain the oil tank. Knock through the old guide bar bolt so that it falls into the oil tank. Remove the bolt from the oil tank. Secure steel wire to the outer part of the bar bolt (A), thread the steel wire through the oil tank and out through the bolt hole in the crankcase.
Page 54
Troubleshooting 8.1 Troubleshooting The various faults that can affect a chainsaw are divided into four groups. In each group the likely symptoms are given on the left and possible causes are listed on the right. The most likely faults are given fi...
Page 55
Troubleshooting High rpm Acceleration och retardation Does not Adjust L screw Will not run at Adjust H screw accelerate Adjust H screw full throttle Blocked air fi lter Blocked air fi lter Blocked fuel tank vent Blocked fuel tank vent Blocked fuel fi...