Service data ............14 Safety equipment ..........16 Repair instructions ..........24 Carburettor ............33 Troubleshooting........... 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 Symbols in the Workshop Manual 9 Symbols on the saw 9 Bar bolt 52 Structure 7 Replacing the bar bolt 52 Target group 7 Tools 7 Carburettor 33 Assemble on the saw 40 Oil pump and screen 31 Assembly 38 Assembling the oil pump and screen 32 Carburettor adjustment 41...
Introduction and safety instructions 2 Introduction and safety instructions Contents General ...........................7 Safety ..........................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 figu- res are designated A, B, etc.
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.
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 Filling with chain oil English –...
Safety equipment 6 Safety equipment 6.1 Dismantling the chain brake Release the brake by moving the front hand guard backward. Loosen the bar nut and remove the clutch cover, chain and bar (see figure 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 figure 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 (see figure 6).
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 firm 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 multime- ter to the ignition coil. NOTE! The switch must be in the “on” (A) position to give the correct reading (see figure 14).
Safety equipment 6.9 Throttle lock, throttle trigger and return spring – removal Loosen the throttle actuator rod on the carburettor, the fuel hose and the suction hose to the fuel pump. Dismantle the tank unit from the engine unit by loosening the screws A (see figure 17) Fig 17 Dismantle the handle insert (B) by loosening the...
Safety equipment 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. Check that the spring is not broken and has not •...
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 figure 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 fly 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 and flywheel – removal Remove the cylinder cover. Disconnect the HT lead, remove the spark plug and fit 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 figure 8).
Repair instructions 7.8 Ignition module and flywheel – refitting Fit the flywheel on the crankshaft journal. Turn the flywheel 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 (see figure 11).
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 figure 13). Disconnect the HT lead. Remove the spark plug and fit piston stop 502 54 15-01 (A) in its place (see figure 14).
Repair instructions 7.10 Centrifugal clutch – refitting Insert the clutch springs in the shoes. 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. 20 Nm. Remove the piston stop.
Repair instructions 7.12 Assembling the oil pump and screen 7.14 Assembling the intake system Fit the chain guide plate with tightening torque Fit the intake manifold (A) and the partition walls 1–1.5 Nm. (B and C) on the cylinder using tool 502 50 87-01 (see figure 21).
Repair instructions 7.15 Carburettor WARNING! The fuel used in the chainsaw has the following hazardous properties: 1. The fluid and its fumes are poisonous. 2. Can cause skin irritation. 3. Is highly inflammable. Description The drawings accompanying this description do not correspond with the carburettor on the chainsaw.
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 figure) 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).
Repair instructions Dismantling the carburettor 1. Dismantle the cylinder cover and the air filter. 2. Disassemble the handle holder (see figure 29). Fig 29 3. Push the throttle actuator rod out of the han- Push the throttle actuator rod out of the han- dle part.
Repair instructions 6. Disassemble the pump cover (G) over the measuring chamber cover (R) and carefully remove the control diaphragm (H) with gasket (J). 7. Unscrew the screw (K) and remove the needle valve (L) with lever (M), shaft (N) and spring (P).
Repair instructions 5. That the tips of the high (V) and low jet screws Cleaning and inspection (W) are not damaged (see figure 34). Clean all units in clean petrol. 6. That the intake manifold (R2) is undamaged Use compressed air to dry the petrol on the com- (see figure 33).
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 refitted. The spring is tensioned 1-2 turns. Lubricate the shaft bearings with light oil.
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.
Repair instructions Assemble on the saw 1. Press the carburettor down towards the parti- tion wall. Make sure that it gets into the correct position. 2. Fit the filter holder by hooking the choke con- trol into the choke lever (A). 3.
• Mount, for this model, approved bar and chain combination (see Technical data in the Fig 43 Operator's Manual). 435/e 16" 440e 16" • The chain should not be tensioned more than that it remains ~ 0,2 inches to the bar.
Repair instructions 7.16 Tank unit WARNING! The fuel used in the chain saw has the following hazardous properties: The fluid and its vapour are poisonous. Can cause skin irritation. Is highly inflammable. Dismantling 1. Drain the fuel from the tank. 2.
Repair instructions 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 insert the fuel hose (in J), return hose (in H) in the bottom of the carburettor compartment (see figure 48).
Repair instructions 7.19 Replacing the fuel filter 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 filter from the tank unit using special tool 502 50 83-01.
Repair instructions 7.22 Piston and cylinder – removal Remove: • cylinder cover • carburettor (see “Carburettor – removal”) • silencer • spark plug • fuel unit Undo the four cylinder bolts from the underside and lift the cylinder off carefully (see figure 52). Fig 53 Cover the opening in the crankcase (see figure 54).
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 fine emery paper.
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.
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 Mount the intake manifold (A) and the partition walls (B and C) on the cylinder using tools 502 50 87-01 (see figure 62).
Repair instructions 7.24 Cylinder – pressure testing Remove: • cylinder cover • carburettor • spark plug Mount cover plate 504 63 93-01 (see figure 63). Fig 63 Loosen the screws on the muffler and press the rubber sheet 502 54 11-02 between the muffler and cylinder.
Repair instructions 7.27 Crankshaft complete – reassembly Fit the crankshaft complete in the crankcase. Refit 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 Fig 70 out through the bolt hole in the crankcase (see...
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 first, and so on.
Troubleshooting High rpm Acceleration och retardation Will not run at Adjust H screw Does not Adjust L screw accelerate Adjust H screw full throttle Blocked air filter Blocked air filter Blocked fuel tank vent Blocked fuel tank vent Blocked fuel filter Blocked fuel filter Fuel line blocked Fuel line blocked...