Husqvarna 445 Workshop Manual
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Husqvarna 445 Workshop Manual

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Workshop manual
445 445e 450e
English

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Summary of Contents for Husqvarna 445

  • Page 1 Workshop manual 445 445e 450e English...

  • Page 3: Table Of Contents

    Service data ............14 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 –...

  • Page 4: Index

    Index Index uf er 19 Bar bolt 52 Assembling the muf er 19 Replacing the bar bolt 52 Dismantling the muf 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 –...

  • Page 7: Introduction And Safety Instructions

    Introduction and safety instructions 2 Introduction and safety instructions 2.1 General 2.6 Structure This Workshop Manual describes in detail how the This Workshop Manual can be used in two diffe- chain saw is to be fault traced, repaired and tested. rent ways: A description of different safety measures that should be taken during repair work is also given.
  • 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 n the a 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 English –...

  • Page 10: Echnical Pecificati N

    3 Technical data Displacement Cylinder bore Stroke a power speed cubic inches inches mm inches hp rpm 445 e 42 1 65 33 1 30 2 0 2 9 000 450e 50 2 3 06 44 1 3 33 1 30...
  • Page 11 Technical data Idling speed Engagement speed Spark plug 445 e 2 00 3 800 BP R A Champion RCJ 7Y 450e 2 00 3 800 BP R A Champion RCJ 7Y Fuel tank capacity Oil pump capacity at Oil tank capacity...

  • Page 12: Service Tools

    Special tools 4 Special tools – English...
  • 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 filter hook ithdrawing the fuel filter 502 50 83-01 Allen key 5 bolts 502 50 8 -01 Allen key For M6 bolts 502 50 64-01...

  • Page 14: Service Data

    Service data 5 Service data 13Nm 13mm 20Nm 19mm 14Nm 13Nm 5.5Nm 1.5Nm 20Nm 1.5Nm 1.5Nm – English...
  • Page 15 Service data 3,5Nm 1,5Nm 23Nm 13mm 3,5Nm 3,5Nm 2.5Nm 3,5Nm 3,5Nm 1,5Nm 3,5Nm 3,5Nm English –...

  • Page 16: Safety Equipment

    Safety equipment 6 Safety equipment Contents Dismantling the chain brake ...................17 Assembling the chain brake ....................18 Dismantling the muf er ....................19 Assembling the muf 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...

  • Page 17: Safety Equipment

    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 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.

  • Page 18: Assembling The Chain Brake

    Safety equipment 6.2 Chain brake – reassembly Bolt the elbow oint 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.

  • Page 19: Dismantling The Muf Er

    Safety equipment perating te t The engine must not be running during the test. Guide bar length Height 38cm 15 50 cm 20 old the chainsaw over a firm surface. The height of the guide bar above the surface is given in the table above.

  • Page 20: Replacing The Chain Catcher

    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.

  • Page 21: Resistance Measurement - Stop Function

    Safety equipment 6.7 t p itch re i tance 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 figure 15) The resistance must not be higher than 0.5 when...

  • Page 22: Dismantling The Throttle Lock, Throttle Control And Spring

    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 (see figure 1 ) 2xE A Fig 17...

  • Page 23: Assembling The Throttle Lock, Throttle Control And Spring

    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.

  • Page 24: Repair Instructions

    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 ywheel ..............28 Assembling the ignition module and ywheel ..............29 Dismantling the centrifugal clutch ...................30 7.10...

  • Page 25: Repair Instructions

    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.

  • Page 26: Changing A Broken Or Worn Starter Cord

    Repair instructions 7.2 hanging a r en r rn tarter 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.

  • Page 27: Changing A Broken Return Spring

    Repair instructions 7.4 Replacing a rn rec il pring WARNING! Make sure the recoil spring does ut an cau e in ur 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.

  • Page 28: Dismantling The Ignition Module And Ywheel

    Repair instructions 7.7 gniti n heel 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) Fig 8 f replacing the ignition module (B) loosen the...

  • Page 29: Assembling The Ignition Module And Ywheel

    Repair instructions 7.8 gniti n ule an heel refitting Fit the ywheel on the crankshaft ournal. Turn the 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 m.

  • Page 30: Dismantling The Centrifugal Clutch

    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.

  • Page 31: Assembling The Centrifugal Clutch

    Repair instructions 7.10 entrifugal clutch refitting 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. 20 Nm. Remove the piston stop.

  • Page 32: Assembling The Oil Pump And Screen

    Repair instructions 7.12 Assembling the oil pump and screen 7.14 Assembling the intake system Assemble the carburettor ange and air ange Fit the chain guide plate with tightening torque 1–1.5 Nm. on the intake bellows. Now assemble the intake bellows and the partition on the cylinder using tool 502 50 87-01.

  • Page 33: Carburettor

    Repair instructions 7.15 Carburettor WARNING! he fuel u e in the chain a ha the f ll ing ha ar u pr pertie he ui an it fu e are poisonous. 2. Can cause skin irritation. highl in a a le 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 n 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).
  • Page 35 Repair instructions Dismantling the carburettor 1. Dismantle the cylinder cover and the air filter. 2. Loosen the bolts (A). 3. Loosen the filter holder from the rubber moun- tings (B). (see figure 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 Cleaning and inspection 5. That the tips of the high (N) and low jet screws (P) are not damaged. (see figure 31) Clean all units in clean petrol. 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 refitted. 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 le n the a 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 figure 40) Fig 40 6.
  • Page 41 • Mount, for this model, approved bar and chain combination (see Technical data in the Fig 42 Operator's Manual). 445 e 450e • The chain should not be tensioned more than that it remains ~ 0,2 inches to the bar.

  • Page 42: Tank Unit

    Repair instructions 7.16 Tank unit WARNING! he fuel u e in the chain a the f ll ing ha ar u pr pertie he ui an it ap ur are poisonous. Can cause skin irritation. highl in a a le Dismantling 1.

  • Page 43: Vibration Damping System

    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.

  • Page 44: Replacing The Fuel Filter

    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.

  • Page 45: Dismantling The Piston And Cylinder

    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 fine emery paper.

  • Page 47: Assembling The Piston And Cylinder

    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 ange (D) and air ange (C) on the intake bellows (A).

  • Page 49: Pressure Testing The Cylinder

    Repair instructions 7.24 Cylinder – pressure testing Remove: • cylinder cover • carburettor • spark plug Attach both the pressure testing covers. (see figure Loosen the screws on the muf er and press the Fig 61 rubber sheet 502 54 11-02 between the muf er and cylinder.

  • Page 50: Dismantling The Crankcase And Crankshaft

    Repair instructions 7.25 Crankshaft complete - dismantling Remove the following: • chain and bar • clutch cover • cylinder cover • starter assembly* • centrifugal clutch* • carburettor* • silencer* • handle system • hand guard • piston and cylinder* Fig 64 * See special instructions.

  • Page 51: Assembling The Complete Crankshaft

    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 •...

  • Page 52: Replacing The Bar Bolt

    Repair instructions 7.29 Replacing the bar bolt Replacing the front bar guide. Drain the oil tank. nock 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 53: Fault Tracing

    Troubleshooting 8 Troubleshooting Contents Troubleshooting ......................54 Troubleshooting methods ....................55 English –...
  • 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 first and so on.
  • Page 55 Troubleshooting High rpm Acceleration och retardation Will not run at Adjust H screw Does not Adjust L screw Blocked air filter accelerate Adjust H screw full throttle Blocked air filter Blocked fuel tank vent Blocked fuel filter Blocked fuel tank vent Blocked fuel filter Fuel line blocked Loose or damaged fuel hose...
  • Page 56 115 03 42-26 2007W16...

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