Husqvarna 343F, 345FX, 345FXT, 343R, 345RX manual

W orkshop manual 343R , 345RX 343F , 345FX, 345FXT English[...]

1 W orkshop Manual Brushcutter , T rimmer Model 343R, 345RX, 343F , 345FX, 345FXT Contents General recommendations ___________________ 2 1. Star ter __________________________________ 3 2. Electrical system _________________________ 7 3. Fuel system _____________________________ 15 4. Centrifugal clutch ________________________ 31 5. Angle g ear __[...]

2 502 51 03-01 General r ecommendations ! ! ! ! ! ! Remember: Nev er star t the engine without the clutch and clutch drum mounted. Do not grasp hot elements such as the muffler or the clutch before the y have cooled sufficiently to a void b ur n injuries. A void getting petrol on you skin or in y our mouth. Use protective cream on y our hands. This[...]

3 1 1. Contents Dismantling _________________________________ 4 Assembly __________________________________ 5 Replacing the dr iv e dogs ______________________ 6 Star ter[...]

4 1 502 50 18-01 Star ter W ARNING! Pr otective glasses should be worn when working on the starter to av oid injur y to the e yes if, for some reason, the return spring should fly out. ! Remov e the bolt in the centre of the star ter pulle y and remove the starter pulley . Remov e the bolt in the centre of the star ter pulley . Lift the star ter pu[...]

5 1 ! Star ter Assembly Clean requisite par ts and assemble in the rev erse order as set out for disman- tling. Assembly Clean all components before assemb ly: Change retur n springs, starter pulley and star ter cord as needed. NO TE! Be careful when opening the packa ging with the return spring so that the spring does not fly out. Attach the sprin[...]

6 1 Star ter Replacing the drive dogs See chapter 2 Ignition system. Replacing the drive dogs See chapter 2 Ignition system. Tighten the retur n spring. Check the spring tension. Tighten the retur n spring. Lift up the star ter cord when the return spring is completely loose and the cord pulled out completely . Then turn the star ter pulley anti- c[...]

7 2 . 2 Electrical system Contents Checking the ignition spark ____________________ 8 Replacing the spark plug cover ________________ 10 Dismantling ________________________________ 11 Drive dogs _________________________________ 12 Assembly _________________________________ 12 Heated handles _____________________________ 12[...]

8 2 502 71 13-01 502 51 91-01 Electrical system The engine is equipped with an electronic ignition system completel y without moving parts. Conse- quently , a faulty component cannot be repaired, but must be replaced b y a new component. The spark in an electronic ignition system has a very short burn time and can theref ore be interpreted as weak [...]

9 2 Electrical system Still no spark? Check the ignition cab le ’ s connection to the spark plug cover . Still no spark? Check the spark plug connection. Remov e the spar k plug cov er and make sure the ignition cable is not damaged. Remov e a segment of cable if required to get sufficient contact at the connec- tion coil. If no spark occurs, dis[...]

10 2 502 50 06-01 502 51 34-02 0.3 Electrical system Replacing the spark plug cover 1 . Inser t the ignition cab le through the spark plug cover . 2. Make a hole in the ignition cab le for the ignition coil. Replacing the spark plug cover 1. Lubr icate the ignition cab le with a little grease and thread it through the spark plug cov er. 2. Cut off [...]

11 2 502 51 94-01 502 54 15-01 502 50 18-01 Electrical system Remov e the nut holding the flywheel. Remov e the flywheel. Remov e the nut holding the flywheel. Remov e the flywheel from the crank- shaft using punch no . 502 51 94-01. Leav e a gap of approx. 2 mm between the punch and the flywheel. Gently knock the punch with a hammer while holding [...]

12 2 502 51 34-02 0.3 502 50 18-01 502 50 18-01 Assembly Check the k ey groov e in the crankshaft and ke y in the flywheel. If damaged the components must be replaced. Attach the ignition module and then the flywheel. Check the air gap , see page 9. Assembly Check that the k ey groo ve in the crankshaft is not damaged. If it is, the crankshaft must[...]

13 2 Electrical system Separate the contacts (A-A) and (B-B). Then extend the cab les (A) and (B) with approx. 90 cm long steel wires attached to the contacts. Separate the contacts (A-A) and (B-B). Then extend the cab les (A) and (B) with appro x. 90 cm long steel wires attached to the contacts. This is to make it easier to dra w the cables to the[...]

14 2 Electrical system[...]

15 3 3. Contents Air filter ___________________________________ 1 6 T ank venting _______________________________ 17 Fuel filter __________________________________ 17 Fuel pump _________________________________ 18 Carburettor ________________________________ 1 8 Assembly _________________________________ 24 Carburettor settings ____________________[...]

16 3 Fuel system In addition to the fuel tank and carburettor , the fuel system consists of the air filter , fuel filter and tank venting. All these components interact so that the engine receives the optimal mixture of fuel and air to make it as efficient as possible. V er y small de viations in the carburettor setting or a bloc ked air filter hav[...]

17 3 531 03 06-23 531 00 60-76 502 50 83-01 T ank venting Chec k that the tank venting valv e works correctly . Replace the fuel cap if the valv e is f aulty . T ank venting T ank venting tak es place through the fuel cap and needs to be functional for the engine to work. • Remov e the fuel hose from the carburettor and empty the fuel from the ta[...]

18 3 505 38 13-08 502 50 18-01 Carburettor Dismantling Blow clean the carburettor compartment. Loosen the bolts (A) and remov e the nuts (B). Remov e the fuel hose (C) and fold the filter holder aside. Carburettor Dismantling 1. Remo ve the carburettor co ver and blo w the carburettor compar tment clean with compressed air . 2. Loosen the bolts (A)[...]

19 3 Fuel system Remov e the throttle cable and fuel hose from the carburettor . Remov e the carburettor . Remov e the throttle cable from the carburettor ’ s lev er ar m using flat nose pliers. Pull off the fuel hose and remov e the carburettor . Tip! Open the fuel cap to a void fuel spillage caused by an y excess pressure. Attach the fuel hose [...]

20 3 531 03 06-23 Fuel system Pressure test the metering unit. Connect pressure tester 531 03 06-23 to the fuel hose nipple. Lower the carb urettor in a vessel with petrol in order to discov er any leaks more easily . T est the pressure at 50 kP a. No leakage is permitted. Dismantling the carburettor Remov e the control diaphragm and check f or dam[...]

21 3 Fuel system Check the needle v alve and the le ver ar m f or damage or wear . Replace damaged components with new ones . Check the needle v alve f or damage on the tip and in the le ver arm groove . Check the le ver arm for damage to the groov e for the needle v alve and wear on the mounting points towards the control diaphragm. Replace damage[...]

22 3 Fuel system Dismantle the main jet (A) and the plug (B). Press out the main jet (A) with a suitable punch. Remov e the plug (B). Carefully drill a small hole ( Ø 2 mm) in the plug and pr y it up with a pointed object. Check v alves and dampers f or wear . Replace if required. Remov e the valv es and dampers. If these components are worn, idli[...]

23 3 Fuel system Assembling the carburettor • Blow all channels in the carb urettor compar tment clean • Mount a ne w plug. Use a suitable punch to get a completely tight seal. • Press in a new main jet. • Mount the v alves and dampers. Tip! Any numbers on the v alves should be able to be read from the outside . Replace the fuel screen if i[...]

24 3 531 03 06-23 Fuel system Check that the carb urettor is sealed. No leakage is per mitted at 50 kP a. Connect pressure tester 531 03 06-23 to the fuel intake on the carb urettor . Pump up the pressure to 50 kP a. Low er the carburettor in a vessel with petrol in order to discov er any leaks more easily . No leakage is permitted. Attach the cont[...]

25 3 T Fuel system The needles must be correctly adjusted in order f or the engine to give maximum pow er at different speeds, run steadily while idling and to react quickly when accelerating. The setting of the carburettor can v ar y a little depending on the humidity , tempera- ture and air pressure. L = Low speed needle H = High speed needle T =[...]

26 3 502 71 14-01 501 60 02-03 Fuel system Correctly adjusted carb urettor A correctly adjusted carb urettor means that the engine accelerates without hesitation and it “ splatters ” a little at full throttle. • A too lean adjusted L-needle can cause star ting difficulties and poor acceleration. • A too lean adjusted H-needle results in low[...]

27 531 00 48-63 531 03 03-98 502 50 18-01 3 Carburettor needles with Zama “ caps ” . Carburettor adjustment 345RX/FX Adjusting the L-needle 1. Mount the T rimmy Fix (4 wires) and use 3.3 mm smooth cord. The cord length should be 160 mm measured from the end of the cord to the cord bushing on the trimmer head. 2. Run the engine warm for about 5 [...]

28 3 G Fuel system Remov e the bolt (A) and remove the throttle from the handle. Remov e bolts (B) and (C). Separate the halv es of the throttle. Remov e the bolt (A) that attaches the throttle to the handle. Be careful not to lose the nut. Remov e the throttle and remove bolts (B) and (C). Carefully separate the two halv es of the throttle. Check [...]

29 3 Disassemble the throttle control (A), the lock to pre vent accidental throttle operation (B), the start throttle lock (C) and the throttle stop (D) in order to check if replacement is necessary . The stop s witch can also be disassem- bled no w , and replaced if necessar y . Use a screwdriv er to press the stop s witch ’ s wing locks (E). Ti[...]

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31 4 4. Contents Dismantling ________________________________ 30 Assembly _________________________________ 32 Clutch dr um _______________________________ 32 Centrifugal clutch[...]

32 4 502 21 58-01 Centrifugal clutch The centrifugal c lutch has the task of transferring the power fr om the engine to the cutting equipment’ s drive axle. As the name implies, it works according to a cen- trifugal principle. This means the c lutch’ s friction shoes are thrown out- wards to wards the c lutch drum at a cer tain engine speed. Wh[...]

33 4 502 54 15-01 Centrifugal clutch Dismantle the clutch from the crank- shaft. Replace the spark plug with piston stop no . 502 54 15-01. Mov e the engine body to the side so that the clutch becomes accessible . Unscre w the clutch from the crankshaft. Remov e the 3 bolts and separate the clutch. Fix the clutch in a vice and remov e the 3 bolts. [...]

34 4 502 52 16-02 502 11 46-03 Centrifugal clutch Assembly T emporar ily place the clutch shoes on the driving disc and loosely tighten the bolts. Pry out the shoes and hook one spr ing to each shoe from underneath. Assembly T emporar ily place the clutch shoes on the driving disc and loosely tighten the bolts. Pr y out the shoes and hook one sprin[...]

35 4 505 38 17-09 Centrifugal clutch Change the bearings in the clutch housing if necessar y . Change the bearings in the clutch housing if necessar y . Remov e the circlip and push out the bearings with a suitable punch and hammer . Dismantling is easier if the clutch housing is heated to about 110 ° C. Assemble in the re verse order as set out f[...]

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37 5 5. Contents Dismantling ________________________________ 36 Assembly _________________________________ 37 Shaft _____________________________________ 38 Angle gear[...]

38 5 Angle gear Dismantling Remov e the cutting equipment and guard. Then loosen the bolts holding the angle gear against the shaft. Remov e the angle gear from the shaft. Dismantling First remov e the cutting equipment (saw b lade, trimmer etc.) and guard. Then loosen the bolts holding the angle gear against the shaft. Remov e the angle gear from [...]

39 5 502 50 65-01 503 97 64-01 Angle gear Remov e the lubr icant top-up plug. W ar m the gearbo x and knock it against a wooden bloc k so that the input axle f alls out. Remov e the lubricant top-up plug and warm the entire gearbox using a hot air gun to about 150 ° C. Knock the gearbo x against a wooden bloc k so that the input axle and bear ing [...]

40 5 503 80 17-01 Angle gear Shaft The shaft contains a drive axle guide that is easily replaced. It can be dismantled once the plastic slee v e (B) has been remov ed. Centre the axle control in the shaft when a new one is fitted. Fit a new O-ring to ensure a good seal. Shaft The shaft contains a long plastic guide to prev ent vibrations in the dri[...]

41 6 6. Contents Dismantling ________________________________ 42 Decompression valv e ________________________ 4 3 Inlet manif old ______________________________ 44 Cleaning, inspection _________________________ 44 Assembly _________________________________ 44 Analysis and actions _________________________ 45 Ser vice tips _________________________[...]

42 6 502 50 18-01 A Cylinder and piston The cylinder and the piston are tw o of the compo- nents exposed to most strain in the engine. They m ust withstand, for example, high speeds, large tempera- ture swings and high pressure. Moreover , the y must be resistant to wear . Despite these tough working conditions, major piston and cylinder failure is[...]

43 531 03 06-23 502 52 42-01 6 Dismantle the piston. Push the gudgeon pin from the piston using punch 502 52 42-01. If the pin is too tight, carefully warm the piston. Decompression valve Dismantle the decompression v alve. Decompression valve Remov e the bolt (A) and the hose (B) that connect the decompression valv e to the nipple on the cylinder [...]

44 6 Cleaning, inspection After dismantling, clean the individual components: 1. Scrape carbon deposits from the top of the piston. 2. Scrape carbon deposits from the cylinder ’ s combustion chamber . 3. Scrape carbon deposits from the cylinder ’ s exhaust por t. 4. W ash all the components. 5. Inspect the diff erent components for damage and w[...]

45 6 502 50 70-01 Cylinder and piston Use a new gask et and fit the cylinder . Make sure that the inlet manif old is correctly connected to the slee ve coupling on the cylinder and that the impulse nipple sits right. Place a new cylinder pedestal gask et on the cylinder . Lubricate the piston and the inlet manif old on the cylinder with a few drops[...]

46 6 Cylinder and piston Action: Change to a fuel with the correct oil mixture. Change to a higher octane petrol. Replace damaged par ts. Replace leaking gaskets and shaft seals. Clean the cooling fins and air intake . Clean or replace the spark arrestor mesh. Cause: • Incorrect oil mixture in the fuel. • T oo low octane fuel. • Air leaks. Cr[...]

47 6 Cylinder and piston Exhaust side damaged by a br oken piston ring. The piston ring par ts damage the top section and cause score marks. Piston damage caused by a too high engine speed. T ypical damage associated with a too high engine speed includes broken piston rings, broken circlip on the gudgeon pin, f aulty bearings or that the guide pin [...]

48 6 Cylinder and piston Small score marks and a matt, grey surface on the piston’ s inlet side caused b y fine dust particles. Cause: • F aulty air filter . Small dust par ticles pass through the filter . • The filter is worn out due to too much cleaning, whereby small holes hav e appeared in the mater ial. • Unsuitable filter maintenance [...]

49 6 Cylinder and piston Cause: • Air filter damaged or missing. • P ar ts from the carburettor or intak e system ha ve come loose and entered the engine. Action: Fit a new air filter . Regular ser vice and inspection. Extensive damage to the lower part of the piston’ s inlet side. Service tips Defect: Broken cooling fins, damaged threads or [...]

50 6 Cylinder and piston Wear tolerances When the surface coating is worn and aluminium appear s. Max. 1.0 mm with the piston ring inserted in the lower part of the cylinder . Max. 1.6 mm. Clean the groove before chec king the measure- ment. Max. 0.15 mm. Clean the gr oove before c hecking the measure- ment. Piston ring play Piston ring groove Pist[...]

51 7 7. Contents Dismantling ________________________________ 52 Inspecting the crankshaft _____________________ 5 4 Assembly _________________________________ 55 Leakage testing the crankcase _________________ 56 Crankshaft and crankcase[...]

52 7 502 50 18-01 Crankshaft and crankcase The crankshaft is journalled in the crankcase on heavy-duty ball bearings. In addition to the journalling point f or the crankshaft, the crankcase acts as a scavenging pump f or the fuel/air mixture when this is “suc ked” from the carb urettor and is for ced into the cylinder’ s combustion chamber . [...]

53 7 502 52 39-01 505 38 17-09 Crankshaft and crankcase Separate the crankcase halv es. Fit tool 502 52 39-01 to the clutch side of the crankcase as illustrated. Separate the crankcase halv es. Fit tool 502 52 39-01 as illustrated. Push out the crankshaft from the crankcase half . Push out the crankshaft from the crankcase half . Remov e the bear i[...]

54 7 Check the crank bearing. Check the cr ank bearing. The connect- ing rod shall not hav e any radial pla y (up and down). It should, how e ver , hav e axial play , in order to ensure good lubrication of the crank bearing among other things. Inspect the crankshaft bearing and sealing rings. Check f or wear in the crankshaft bearing and sealing r [...]

55 7 502 50 30-19 502 50 30-19 Crankshaft and crankcase Check that the there is no pla y in the fill-out plates around the crank disks (applies to models F X /F XT , R X ). Check that the there is no pla y in the fill-out plates around the crank disks (applies to models F X /F XT , R X ). Assembly Mount the bearings in the crankcase halves . Assemb[...]

56 7 505 38 17-09 502 54 11-02 503 84 40-01 Crankshaft and crankcase Leakage testing the crankcase Fit the two sealing plates (A) and the pressure test nipple (B). Leakage testing the crankcase Remov e the throttle cable and air filter holder from the carburettor . Fit a sealing plate (A) 502 54 11-02 between the carburettor and the distance piece [...]

57 7 531 03 06-23 503 55 22-01 Crankshaft and crankcase Fit plug 503 55 22-01 instead of the decompression valv e. Connect meter 531 03 06-23 and check f or leakage. Fit plug 503 55 22-01 instead of the decompression valv e. Connect meter 531 03 06-23 to the nipple and pump up a pressure of 50 kP a (0.5 kp/cm 2 ) in the crankcase. Max. per mitted l[...]

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