Husqvarna 340, 345, 346XP,350, 351, 353 manuale d’uso

W orkshop manual English 340 345 346XP 350 351 353[...]

English – 1 W orkshop manual Husqvarna 340/345/346XP/350/351/353 Contents Introduction ........................................................... 2 Safety regulations ................................................. 3 General instructions ........................................... 3 Special instructions ........................................[...]

2 – English Arrangement of the manual This workshop manual can be used in two different ways. • T o repair a specific sub-assembly on a chainsaw . • T o dismantle and reassemble a complete chainsaw . Repairing a specific sub-assembly If a specific sub-assembly on the chainsaw needs to be repaired: 1. Look up the page referring to the relevant[...]

English – 3 General instructions This workshop manual gives detailed instructions on how to troubleshoot, repair and test a chainsaw . This section also describes the various safety precautions that should be taken when carrying out repairs. The workshop manual has been written for person- nel who are assumed to have general experience of repairi[...]

4 – English Special tools 4 5 8 11 12 10 1 2 3 14 6 9 7 13[...]

English – 5 Item Description Used for Order no. 1 Clutch tool Centrifugal clutch 502 54 16-01 2 Piston stop Locking crankshaft 502 54 15-01 3 Stop plate Locating intake gaiter 502 54 17-01 4 Fuel filter hook Withdrawing the fuel filter 502 50 83-01 5 Allen key For M5 bolts 502 50 18-01 6 Puller Frame bearing 504 90 90-02 7 Removal tool Remove sea[...]

6 – English Displacement Cylinder bore Stroke Max power/speed cm 3 /cubic inches Ø mm/Ø inches mm/inches kW/hp/rpm 340: 40,8 / 2,44 40 / 1,57" 32 / 1,28" 2,0 / 2,7 / 9 000 345: 45,0 / 2,75 42 / 1,65" 32 / 1,28" 2,2 / 3,0 / 9 000 346XP/G: 45,0 / 2,75 42 / 1,65" 32 / 1,28" 2,5 / 3,4 / 9 600 350: 49,4 / 3,01 44 / 1,73[...]

English – 7 Technical data Idling speed Engagement speed Max. speed Spark plug rpm rpm rpm 340: 2 700 3 800 12 500 NGK BPMR 7A, Champion RCJ 7Y 345: 2 700 3 800 12 500 NGK BPMR 7A, Champion RCJ 7Y 346XP/G: 2 700 3 800 14 200 NGK BPMR 7A, Champion RCJ 7Y 350: 2 700 3 800 13 000 NGK BPMR 7A, Champion RCJ 7Y 350 EP A: 2 700 3 800 13 000 NGK BPMR 7A,[...]

8 – English The carburettor works in different ways depending on the setting: • Cold start mode • Idling mode • Part throttle mode • Full throttle mode In the cold start mode the choke valve (D) is completely closed. This increases the vacuum in the carburettor so that fuel is sucked through the diffuser jets faster (E). In idling mode th[...]

English – 9 Construction and function In part throttle mode the throttle valve (F) is par- tially open. Fuel is supplied through the diffuser jets (E). In full throttle mode both valves are open and fuel is supplied through all the diffuser jets (E).[...]

10 – English T roubleshooting Worn needle valve Leaking control diaphragm/ cover plate Needle valve assembly sticking Worn needle valve lever Faulty diffuser jet Fuel filter blocked Fuel line blocked Leaking air intake hose (rubber) Loose carburettor mounting bolts Worn throttle valve pivot Loose throttle valve screw Worn throttle valve Needle va[...]

English – 11 Troubleshooting Acceleration and retardation Does not accelerate Engine stalls when throttle released Over rich acceleration Adjust L screw Adjust H screw Blocked air filter Blocked fuel tank vent Blocked fuel filter Fuel line blocked Loose or damaged fuel hose Impulse channel blocked Loose cover on carburettor pump side Faulty pump [...]

12 – English 3 WARNING! Make sure the spring does not fly out and cause injury. Wear eye protection. Repair instructions Chain brake – dismantling 1 Disengage the brake by pushing the kickback guard backwards. Unscrew the guide bar bolts and remove the clutch cover , chain and guide bar . 2 Grip the clutch cover carefully in a vice. Release the[...]

English – 13 Repair instructions NOTE! After completing the repair the chain brake must be tested as described below. 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 ab[...]

14 – English WARNING! Do not touch the silencer until it has cooled down, otherwise you may burn yourself. Repair instructions Remove the chain catcher and replace it with a new one. Check that the vibration damping spring locates correctly against the crankcase when you bolt the new chain catcher in position. A worn (damaged) chain catcher on 34[...]

English – 15 Repair instructions Stop switch – removal 1 Remove the cylinder cover and air filter . 2 Disconnect both leads from the stop plate and stop switch. Remove the stop plate by carefully sliding it over the lug on the front mounting. 3 Carefully prise the carburettor assembly off the left- hand rubber mounting using a small screwdriver[...]

16 – English Repair instructions Choke control – removal 1 Remove the cylinder cover , air filter and stop switch. Disconnect the fuel hose from the carburet- tor . Stop switch – refitting 1 Carefully press the new stop switch into place. Check that the switch’s upper mounting clips over the air filter holder . 2 Refit the stop plate. Engag[...]

English – 17 Repair instructions Cleaning and inspection • Clean and inspect all parts carefully . If there are any cracks or other defects replace the damaged parts with new ones. Always use original parts. • Lubricate the throttle lock with oil. • Check that the spring is not broken and has not lost its tension. Throttle lock, throttle tr[...]

18 – English Hand grip heater on model 346XPG, 351G, 353G – removal No heating or heating only in front hand grip • Front hand grip – troubleshooting 1 Remove the three bolts that secure the cover over the front hand grip. Disconnect the leads from the switch and generator and measure the resistance of the hand grip heater , which should be[...]

English – 19 Unscrew the two bolts from the right side of the rear hand grip. Remove the throttle lock and throttle handle, see “Throttle trigger”. Pull out the heater element with the leads still connected. T roubleshooting carburettor heater (346XPG, 351G, 353G) Operation The carburettor temperature is controlled by an electronic thermostat[...]

20 – English Repair instructions Heater element and rear hand grip – removal 1 Remove the cylinder cover , hand grip cover , hand grip and right-hand stop. Then remove: • throttle lock, throttle trigger and recoil spring, see “Throttle trigger”. • fuel hose and throttle pushrod from the carburettor Unbolt the rear tank mounting from the[...]

English – 21 Repair instructions WARNING! If the recoil spring is still under tension when the pulley is re- moved it can fly out and cause in- jury. Wear eye protection. Starter assembly – removal 1 Undo the four bolts that fasten the starter assembly to the crankcase and lift off the starter assembly . 2 Pull out about 30 cm of the cord and f[...]

22 – English Repair instructions WARNING! Make sure the recoil spring does not fly out and cause injury. Wear eye protection. Replacing a worn recoil spring 1 Remove the bolt from the centre of the pulley and lift off the pulley and spring. 2 Remove the broken recoil spring. 3 Fit the bolt through the centre of the pulley and tighten to a torque [...]

English – 23 Repair instructions Ignition module – testing If there is a fault in the ignition system the ignition module must be tested before the ignition system is removed. T est the ignition module as follows: • Connect a test spark plug 502 71 13-01 to the ignition lead and clip the test spark plug onto the cylinder . • T urn the engin[...]

24 – English Repair instructions Generator – refitting 1 Feed the generator lead through the holes in the crankcase and hand grip. Bolt the generator in position, tightening the bolts to a torque of 5 Nm. Clip the lead to the tank. NOTE! The lead connector must be positioned on the right of the clip, see diagram. Connect the lead to the connect[...]

English – 25 Repair instructions 3 Then refit: • cable guide and press the leads into position • HT lead • starter assembly , tighten to a torque of 2.5–3.5 Nm • cylinder cover Ignition module and flywheel – refitting 1 Place the flywheel on the crankshaft. T urn the flywheel so that the key lines up with the keyway in the shaft. Fit [...]

26 – English Repair instructions Centrifugal clutch – removal 1 Remove the cylinder cover . Disengage the chain brake by pushing the kickback guard backwards. Undo the guide bar bolts and remove the clutch cover , chain and guide bar . 2 Unbolt the clutch using tool 502 54 16-01 and a suitable socket or combination spanner . T urn the nut clock[...]

English – 27 Repair instructions Fit the clutch onto the crankshaft and tighten anticlockwise as far as it will go. Then tighten to a torque of at least 20 Nm using tool 502 54 16-01 and a suitable socket or combination spanner . 3 Remove the piston stop. Fit the spark plug, tightening it to a torque of 15 Nm, then connect the HT lead. Then refit[...]

28 – English Repair instructions Cleaning and inspection • Clean and inspect all parts carefully . If there are any cracks or other defects replace the damaged parts with new ones. Always use original parts. • Lubricate all moving parts with chain oil. Carefully lift out the oil pump from the crankcase. 6 Push the crankcase up a little from t[...]

English – 29 Repair instructions Fit the chain guard plate, tightening the bolts to a torque of 2–3 Nm. Model 350: Fit the bolts on the anti-vibration elements on the same side. 6 5 A C D B Lubricate the needle bearing with grease. Fit the pump drive wheel (D), needle bearing (C), chain sprocket (B), if fitted, and clutch drum (A). 7 Fit the cl[...]

30 – English Repair instructions Recommended setting: 13–15" bar Min. setting 15–18" bar Midway setting 18–20" bar Max. setting Adjustable oil pump – adjustment 346XP , 350, 351, 353 Use a screwdriver or adjustable spanner to turn the adjuster screw on the pump. T urning the screw clockwise decreases the oil flow and turnin[...]

English – 31 Repair instructions When replacing the thermostat: Disconnect the cable from X and V . T rouble shooting, see page 20. On saws with carburettor 346XPG, 351G, 353G Replacing the heating element: Lower the rear section of the tank by removing the bolt between the hand grip cover and vibration damping springs. Remove the starter and the[...]

32 – English Repair instructions Fit the needle valve with lever arm, spindle and spring and tighten the screw . Use a rule to check that the lever arm is level with the cover face. If necessary , the lever arm can be bent slightly . 7 Fit the metering diaphragm with its gasket and refit the cover to the metering unit. 8 Carry out pressure testin[...]

English – 33 Repair instructions Carburettor – pressure testing Pressure testing should be carried out with the carburettor fully assembled. T esting should always be carried out after the carburettor has been repaired, but can also be performed for trouble- shooting before dismantling. Carry out the test as follows: • Screw in the high and l[...]

34 – English Repair instructions Push the rear carburettor mounting into its rubber bushing using a small screwdriver . Remove stop plate 502 54 17-01. 4 5 Connect the leads to the stop switch. Fit the carburettor . Screw in the carburettor bolts directly from behind, without lifting the carburettor assembly . T ighten to a torque of 1–1.5 Nm. [...]

English – 35 Repair instructions Unbolt the vibration damping spring between the cylinder and hand grip. 3 Unscrew the four cylinder bolts. Lift up the cylinder so that the intake system insulating plate is free of the crankcase. 4 On models 340 and 345 there are cylinder bolts on the underside. 5 Air intake system – removal The air intake syst[...]

36 – English Refit the carburettor . Screw in the carburettor bolts directly from behind without lifting the carburettor assembly , tightening to a torque of 1–1.5 Nm. It is important to hold the carburettor flange securely when tightening the bolts to prevent the inlet manifold from moving. 4 4 Push down the rear carburettor mounting into the [...]

English – 37 Repair instructions Carburettor – adjustment For instructions on adjusting the EP A carburettor see appendix A. Adjusting the carburettor involves adjusting the engine to the local conditions e.g. climate, alti- tude, fuel and type of two-stroke oil. The carburettor is equipped with three adjustment options. L = Low speed jet H = H[...]

38 – English 1 Empty the fuel tank. 2 Remove the following: • cylinder cover • air filter • clutch cover • chain and guide bar • starter assembly • cable guide 3 Disconnect the fuel hose from the carburettor . 4 Fuel tank – removal WARNING! The fuel used in chainsaws is harmful if inhaled, may cause skin irritation and is highly fla[...]

English – 39 5 Unscrew both stops and the three vibration damp- ing springs from the flywheel side and clutch side of the engine. 6 Disconnect and remove the fuel hose from the crankcase. Repair instructions Cleaning and inspection Carefully check that: • there are no leaks from the fuel tank • there are no leaks from the tank filler cap • [...]

40 – English Connect the fuel hose to the carburettor . Check that the hose is not kinked or too long to be clamped between the crankcase and tank. The correct hose length between the tank and crank- case is 43 mm (1.69 inches). The correct hose length between the crankcase and carburettor is 53 mm (2.09 inches) excluding the mitred section. 5 Fi[...]

English – 41 Repair instructions Undo the four cylinder bolts and lift the cylinder off carefully . Models 340, 345 Piston and cylinder – removal 1 Remove: • cylinder cover • carburettor (see “Carburettor – removal”) • silencer • spark plug • fuel tank (applies to 340, 345) 2 Unbolt the vibration damping spring from the hand gri[...]

42 – English • Measure piston ring wear . This should not exceed 1 mm. Use the piston to push down the piston ring. • The needle roller bearing is undamaged. • The inlet manifold is undamaged. • Pressure test the decompression valve. • Also refer to Jonsered’s Analysis guide for piston failures, art. no. 108 07 01-01. Decompression va[...]

English – 43 Repair instructions Piston and cylinder – refitting 346XP , 350, 351, 353 1 Fit the piston with the arrow pointing towards the exhaust port. Push in the gudgeon pin and fit the circlips. If replacing the cylinder , fit the decompres- sion valve, tightening to a torque of 12–14 Nm. 3 Lubricate the little end bearing with two-strok[...]

44 – English NOTE! If a new piston or cylinder has been fitted the saw must be run for the first 3 – 4 hours with carburettor adjusted to the factory settings. Piston and cylinder – refitting 340, 345 1-5 See Piston and cylinder 346XP , 350, 351, 353 – Refitting points 1-5. 6 Apply silicone adhesive/sealing compound (03- 7062) to the crankc[...]

English – 45 Repair instructions Crankcase and crankshaft – dismantling 346XP , 351, 353 1 Remove the following: • guide bar and chain • clutch cover • cylinder cover • starter assembly* • ignition system* • generator* • centrifugal clutch* • oil pump* • bark rest • chain tensioner • throttle pushrod • carburettor* • c[...]

46 – English Crankshaft bearings – replacement 346XP , 351, 353 If the crankshaft bearings are to be replaced, tap them out gently using drift 502 70 84-01. The new bearings must be shrunk-fit into the crankcase using a hot air gun. Cleaning and inspection Clean and inspect all parts carefully . Sealing ring – replacement Remove the sealing r[...]

English – 47 Repair instructions Cleaning and inspection Clean and inspect all parts carefully . Sealing ring – replacement Remove the sealing ring from the crankcase using a small screwdriver . NOTE! Take care to avoid damaging the crank- case. T o fit the sealing ring use the sleeve that is sup- plied with 502 50 30-16. The end with the half [...]

48 – English 4 Fit and tighten the six crankcase bolts to a torque of 8–10 Nm. Check that the crankshaft rotates freely . 5 Refit the following parts: • bark rest • oil pump* • chain tensioner • centrifugal clutch* • fuel tank* • piston and cylinder* • generator* • carburettor base • carburettor* • throttle pushrod • silen[...]

English – 49 Repair instructions Repairing damaged threads A repair kit, 503 27 33-01, is available for repairing damaged threads. First drill out the hole using: 6.1 mm drill bit for magnesium crankcase Then screw in the thread insert using a suitable bolt and spanner . Thread insert A damaged thread can be repaired using a thread insert. The sl[...]

50 – English Appendix A Repair instructions Basic adjustment for EP A II carburetors After replacing the carburetor or high speed and/or low speed needle on an EP A (The US Environmental Protection Agency) certified product a basic adjustment must be carried out as described below in order to meet the EP A-requirements. This to achieve as low emi[...]

English – 51 2003W12 1 14 01 47-26[...]