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Workshop manual
HusqvarnaHedgetrimmers
English
2
3
Workshop ManualHedge trimmers
1. Starter ___________________________________ 5
2. Ignition system ____________________________ 7
3. Fuel system _______________________________ 9
4. Centrifugal clutch _________________________ 13
5. Gear ____________________________________ 17
7. Crankshaft and crankcase__________________ 25
8. Exhaust system __________________________ 27
9. Cutting equipment ________________________ 31
© Copyright Husqvarna AB, Sweden 2000
This supplement only takes up elements specificto the above mentioned models.
For complete information when servicing we rec-ommend that the supplement is studied together
with the Workshop Manual.(Order no. 101 90 74-26)
and the supplement for brushcutters, trimmers,pruners and hedge trimmers.
(Order no. 101 90 75-26)
Supplement for models 325HS, 325HE,325HDA
Contents
4
5
1.Starter
ContentsGeneral ___________________________________ 6
Replacing the drive dogs, supplement ___________ 6
6
1
504 90 00-02
4 mm
Starter
WARNING!Protective glasses should be worn when working on the starter to avoid injury to theeyes if, for some reason, the return spring should fly out.
!
Replacing the drivedogs, supplement.
Make sure the ear on the drive cup isfitted in the cut-out on the crankshaft.
Replacing the drivedogs, supplement
325HS75, 325HS99
Fit the balance weight in the drive cup,if necessary.
Fit the drive cup on the crankshaft.
NOTE!Risk for incorrect assembly. If theweight is fitted on the wrong side of thedrive cup the blades will vibrate heavilywhen the engine is running.
Deviations:
Starter handle placement. The drivecup is fitted with a balance weight.
GeneralSee Brushcutter 325.
The balance weight should be facingthe spark plug when the piston is in topdead centre.
7
2.Ignition system
ContentsGeneral 8
Assembling the cylinder cover 8
8
2
504 90 00-02
4 mm
The spark in an electronic ignition systemhas a very short burn time and can thereforebe interpreted as weak and can be difficult tosee while trouble shooting.
Deviations:The cylinder cover is located using fourscrews instead of three. (325HS)
325HS: The speed is limited to 11,600rpm.
325HDA55/325HE: The speed is limitedto 10,000 rpm.
General
325HS75, 325HS99, 325HE2, 325HE3,325HE4: See Brushcutter 325.
The thick threaded screw (for the clipset) should be placed in the holeclosest to the gearbox.
Assembling the cylindercover
325HS75, 325HS99:
Check that the ignition cable is inposition in the cut-out in the gearbox.
Align the cylinder cover with the slot forthe screw pin, make sure that when thecover is moved down that the ignitioncable is secured by the wedge shapedcut-out in the cylinder cover.
Assembling the cylindercover
325HS75, 325HS99:
Fit the cylinder cover.
NOTE!Risk for incorrect assembly.
The ignition cable can be damaged bythe flywheel if incorrectly routed. Theprotective casing on the ignition cablemust be clamped in the securing ear (toget sufficient length of ignition cable tothe wedge shaped cut-out).
If the wrong screw is placed in the holeclosest to the gearbox the threads inthe clip set will be crossed.
Ignition system
The engine is equipped with an electronic ignitionsystem completely without moving parts.Consequently, a faulty component cannot berepaired, but must be replaced by a new compo-nent.
9
3.Fuel system
ContentsGeneral __________________________________ 10
Assembling the fuel tank ____________________ 10
Max speed, modification _____________________ 11
Assembling the cylinder cover ________________ 11
10
3 Fuel system
In addition to the fuel tank and carburettor, thefuel system consists of the air filter, fuel filter andtank venting.All these components interact so that the enginereceives the optimal mixture of fuel and air tomake it as efficient as possible. Very small devia-tions in the carburettor setting or a blocked air
filter have a large effect on the running andefficiency of the engine.The carburettor can come from several differ-ent manufacturers on our models, yet thefunction and repair methods are essentially thesame.
General
325HS75, 325HS99, 325HDA55325HE3, 325HE4:
See Brushcutter 325.
Deviations:Fuel tank and modified design. Thecylinder cover is secured by fourscrews. (325HS)The speed is limited to 11,600 rpm.(325HS)The carburettor´s needle H is notadjustable.(325HDA, 325HE)The speed is limited to 10,000rpm.(325HDA, 325HE)
Thread on two rubber supports on topof the tank.
Position two rubber supports for thetank on the engine.
Position the tank and align it on therubber supports; press down the tank.
Assembling the fueltank
325HS75, 325HS99:
Connect the fuel hoses.
11
3
Fit the starter.
502 71 14-01
Fuel system
Max speed, modification
325HS75, 325HS99, 325HE 2, 325HE 3, 325HE 4:
Model 325HS has an ignition system with speed control set at 11,600 rpm.
Models 325HDA and 325HE have an ignition system with speed control set at10,000 rpm.
Use the tachometer 502 71 14-01 to check the speed.
If the speed is too low, check that the cutting equipment does not jam.
Assembling the cylinder cover
325HS75, 325HS99:
Fit the cylinder cover, see the instructions under chapter 2 Ignition system.
NOTE!Risk for incorrect assembly.
The ignition cable can be damaged by the flywheel if incorrectly routed. Theprotective casing on the ignition cable must be clamped in the securing ear (to getsufficient length of ignition cable to the wedge shaped cut-out).
If the wrong screw is placed in the hole closest to the gearbox the threads in theclip set will be crossed.
Pull the starter handle a little so that thestarter falls into place and position thescrew by the starter handle to secure.
12
13
4.Centrifugal clutch
ContentsDismantling 14
Assembling 15
14
4
504 91 06-05
Centrifugal clutch
The centrifugal clutch has the task of transferringthe power from the engine to the cutting equip-ment’s drive axle. As the name implies, it worksaccording to a centrifugal principle. This means the clutch’s friction shoes are thrownoutwards towards the clutch drum at a certainengine speed. When the friction against the drumis sufficiently great it drives the drive shaft at thesame speed as the engine.
Some slipping occurs between the clutch andthe clutch drum when accelerating as well asin the reversed situation when the cuttingequipment jams. Thereby preventing abnormalload changes on the crankshaft.The engagement speed has been carefullytested so that the engine can idle without thecutting equipment’s drive shaft rotating.
Dismantling
325HS75, 325HS99:
Remove the engine, see 9 Cutting equipment \ Dismantling the gearbox on 325HS.
NOTE!Both the clutch shoes and spingsshould be replaced if damaged. This isto ensure that no imbalance occurs andthat the correct clutch speed is ob-tained.
Inset the piston stop 504 91 06-05.
Remove the screws holding the clutchshoes and remove the clutch shoes andsprings.
15
4
6 mm
504 90 00-01
5 mm
504 90 00-03
Centrifugal clutch
Secure the clutch bridge screws usinga weak thread lock fluid.
Tighten the screws with 8-10Nm.
Fit the clutch bridge.
Fit the clutch drum and washer. Securethe screws using a weak thread lockfluid.
Lock the cutting equipment by placing a6 mm allen key through the hole in thebottom of the gearbox and tighten theclutch drum screw to 22 Nm.
Assembling
325HS75, 325HS99:
Assembling the clutch drum.
Lock the cutting equipment by placing a6 mm allen key through the hole in thebottom of the gearbox and loosen theclutch drum screw using a 5 mm allenkey. Remove the screw, washer andclutch drum.
Remove the clutch bridge from theflywheel.
Remove the clutch drum if it is dam-aged or worn.
Fit the clutch shoes.
NOTE!Risk for incorrect assembly.
Turn the clutch shoes so that the cut-out in the free end section facestowards the clutch bridge, so that thescrew heads are sunken.
Tighten the screws with 8-10Nm.
16
4
Fit the engine see 9 Cutting equipment \ Fit the gearbox.
Centrifugal clutch
17
5.Gear
ContentsGeneral __________________________________ 18
Dismantling _______________________________ 18
Assembling _______________________________ 21
18
5
504 90 00-02
4 mm
Gear
The gear has two purposes:The first is to gear down the engine’s high speedto better suit the lower speed a blade or trimmerrequires to work efficiently.
Secondly, the gear contributes towards theoperator’s working stance so that it is com-fortable and at the same time efficient. Thistherefore means that cutting equipment isadjustable in relation to the shaft. The settinglimits the angle limiter.
General
325HDA55, 325HE3, 325HE4
See Brushcutter 325.
Dismantling
325 HDA55, 325HE3, 325HE4
Remover the angle limiter.
Remove the cover from the angle gearhousing.
Remove the support plate for thecutting equipment.
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5
504 90 00-02
4 mm
Remove the two screws. Counter holdon the axle’s spanner flats.
Remove the housing from the shaft.
Remove the circlip (locking washer) onthe cog wheel in the angle gear.
Remove the circlip and bearing fromthe pinion, if necessary.
Remove the outer circlip on the pinionfrom the housing for the shaft.
Remove the pinion from the housingfor the shaft.
Use small circlip pliers for the axle andpuller 504 90 90-01.
Heat using a hot air gun to approx.125°C and knock against a woodensurface.
Remove the axle and crown wheel fromthe angle gear.
Gear
20
504 90 00-04
3 mm
504 90 00-04
3 mm
5
Remove the cog wheel.
Remove the gearbox cover. With bearing replacement: Heat using ahot air gun to about 125°C and knockagainst a wooden surface.
Remove the eccentric cams.
Remove the felt seals.
Remove the locking plate.
Remove the wear washer.
Remove the connecting rod.
Gear
21
!
5
503 98 96-01
WARNING!Wear gloves!
Make sure the blades move easily.
Place one of the wear washers inposition in the gearbox.
Turn the wear washer with roundededges towards the blades.
Fit and tighten the outer screws for thesupport plate with washers as normal.
Fit the lock nut.
Loosen the screw a 1/4 turn and checkthat the washer moves.
Tighten the lock nut.
Assembling
325DA55, 325HE3, 325HE4
Use weak nut lock fluid when assem-bling.
Lubricate the components with grease503 98 96-01 when assembling.
Fit the bearing and circlips.
Fit the cutting equipment.
Fit the support plate for the cuttingequipment.
Remove the circlips for the bearings.Heat using a hot air gun to approx.125°C and press out the bearing.
The eccentric cam’s bearing, 27 mmpunch 502 50 30-04,crown wheel axle’s bearing, 22 mmpunch.
Remove the bearing.
Two screws, the outer accessiblethrough the hole in the cutting equip-ment when the blades are moved.
Remove the cutting unit.
Lift the blades a little using a screw-driver and remove the remainingconnecting rod.
Remove the wear washer.
Gear
22
503 98 96-01
504 90 00-04
3 mm
5Lift the blades a little using a screw-driver and fit the connecting rod.
Turn the connecting rod with therounded edges facing upwards andguide in the cutting equipment.
Fit new felt seals. Risk for incorrect assembly:
Position the felt seals in the two outercompartments, see picture.
Position the eccentric cams. Align the connecting rod, turn by handand check that the blades movewithout jamming.
Fit the connecting rod. Turn the connecting rod with therounded edges facing towards theeccentric cam and guide in the cuttingequipment.
Fit the wear washers. Turn the wear washer with the roundededges facing towards the eccentriccam.
Fit the locking plate.
Avoid misalignment. Make sure thecover sits correctly and fit the screws,tighten crosswise.
Fill the gearbox 2/3 full with grease
503 98 96-01.
Fit the gearbox cover.
Gear
23
504 90 00-02
4 mm
503 98 96-01
5
Fit the bearing with circlip on thepinion.
Fit the pinion with bearing in thehousing for the shaft.
Heat the housing with a hot air gun.Press in the pinion to the stop and fitthe outer circlip.
Use a new circlip and make sure it isnot deformed when positioning. Makesure the circlip has a good grip.
Fit the cog wheel and a new circlip onthe axle to the gearbox.
Fit the axle with crown wheel in theangle gear.
Fit the housing for the shaft. Two screws with washers. Counterhold on the axle’s spanner flats.
Fill the angle gear 2/3 with grease503 98 96-01.
Fit the cover on the angle gear. Turn the cover with the cut-out facingtowards the housing for the shaft.
Gear
24
5 Gear
Fit the angle limiter.
Check that it is possible to turn theinput axle with a screwdriver withoutjamming or jumping and that the bladesfunction normally.
25
7.Crankshaft and crankcase
ContentsDismantling _____________________________________ 26
Assembling _____________________________________ 26
26
7
The crankshaft is journalled in the crankcase onheavy-duty ball bearings. In addition to thejournalling point for the crankshaft, the crankcaseacts as scavenging pump for the fuel/air mixturewhen this is “sucked” from the carburettor and isforced into the cylinder’s combustion chamber.The crankcase must be perfectly sealed so as notto affect this pump function. There cannot be anyleakage either from the crankshaft or between thecrankcase halves or between the crankcase andthe cylinder.Always replace the sealing rings and gasketswhen servicing the crankcase.
Dismantling325HS75, 325HS99
Dismantle all components so that onlythe crankcase and crankshaft remain.
Now lift the crankshaft out of thecrankcase.
Remove the ball bearing and thebalance cup.
Dismantling325HS75, 325HS99
See respective sections for detailedinformation if necessary.
The bearing has a sliding fit on theshort spindle and a press fit on the longspindle.
Puller 531 00 48-67 for the bearing witha press fit.
Assembly325HS75, 325HS99
Check the crankshaft as set out in thesection “Checking the crankshaft” in theWorkshop Manual.
Clean the contact surfaces on thecrankcase. Lubricate the sealing lips onthe stuffing boxes with a thin layer ofgrease.
Fit the balance cup and new bearing onthe crankcase’s short spindle with thebearing’s open side facing inwardstowards the crank disc.
Punch 502 50 30-13.
Wedge in a shim between the balanceweights, press on the ball bearing onthe long spindle with the stuffing boxturned towards the crank disc. Turn alittle on the outer ring while pressing sothat the stuffing box enters on its collar.Remove the shim.
Lubricate the big-end bearing with afew drops of engine oil and position thecrankshaft in the crankcase.
Assemble all the remaining parts in thereverse order as set out for dismantling.
See respective sections in the Work-shop Manual.
Leakage test the crankcase according tothe instructions in the Workshop Manual.
Crankshaft and crankcase
The task of the crankshaft is to transfer the recipro-cating motion of the piston to rotation. To do thisrequires a stable design withstanding immensepressure, rotational and bending strain as well ashigh rotational speed. In addition the connecting rodis exposed to large acceleration and retardationforces as it moves between top and bottom deadcentres. This puts special demands on the bearingsthat must withstand quick changes in load. Besides,the bearing’s roller retainer also must cope with hightemperatures and friction. Therefore it is extremelyimportant when servicing, to check the roller retainerfor cracking, wear and discolouration due to over-heating.
27
8.Exhaust system
ContentsGeneral 28
Dismantling the muffler 28
Assembling 29
28
8
504 90 00-02
4 mm
Exhaust system
Deviations:
325HS75, 325HS99
Spacer for the muffler is not fitted onthe brushcutter.
General
See Brushcutter 325.
NOTE!Make sure the spacer does not falldown when the muffler is removed.
Remove the muffler.
Remove the two screws holding themuffler guard.
Dismantling the muffler
325HS75, 325HS99
Remove the muffler guard.
Remove the two screws holding themuffler.
The exhaust system is an important part of a two-stroke engine to maintain the right engine power.It is therefore tuned at the factory to dampen thenoise and give the best engine power.When running with a too rich fuel mixture themuffler will be blocked by the residual deposits,which can mean that a sufficiently high speed isnot attained, and the engine power drops.
Even if the muffler does not have sufficient innerresistance, the engine power can drop at the sametime as the engine noise increases.Change the muffler if the exhaust noise isabnormal.
29
8Exhaust system
Fit the muffler guard.
AssemblingFit a 4 mm allen key, as a guide pin, inthe upper hole to fix the spacer insidethe fin and guide the componentstowards the cylinder.
Fit the muffler’s lower mounting screw.
Remove the allen key and fit the uppermounting screw.
NOTE!Assembly order: Cylinder - spacer - fin- muffler. Otherwise the ignition cablecan come in the wrong position.
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9.Cutting equipment
ContentsRemoving the gearbox ______________________ 32
Dismantling the gearbox _____________________ 33
Assembling the gearbox _____________________ 35
Dismantling the cutting equipment _____________ 36
Sharpening the blades ______________________ 36
Assembling the cutting equipment _____________ 36
Fitting the cutting equipment _________________ 37
Fitting the gearbox _________________________ 37
Changing the front springs ___________________ 39
Changing the rear springs ___________________ 39
32
9
!
Cutting equipment
WARNING!
The transport guard should always be fitted when working on the cuttingequipment to avoid cuts to the hands. Wear protective gloves if necessary.
Removing the gearbox
325HS75, 325HS99:
Remove the cylinder cover.
See Starter.
Remove the heat guard over themuffler.
Remove the starter.
Release the handle from the frame.
33
9
Dismantling thegearbox
325HS75, 325HS99:
Remove the screws holding the cover.
Lift off the cover.
Replace the bearing if necessary:
Remove the screws holding theengine on the gearbox, release theelectrical cables and remove theengine.
Replace the bearing:
Heat the cover with a hot air gun toapprox. 125°C.
Knock the cover against a woodensurface, open carefully with ascrewdriver if necessary.
When assembling press the bearingagainst the stop, check that thebearing race lies under the edge ofthe housing.
Sealed bearing 26 mm punch 502 5205-01, Non-sealed bearing 28 mmpunch502 50 30-04.
Remove the guide plate.
Remove the felt seal.
Remove the thrust washer.
Remove the flat washer.
Remove the lower connecting rod.
Remove the three lock nuts for theblades and support plates.
NOTE!The connecting rod has a needlebearing on the big end, exercisegreat care so that it does not fallapart. The needles (53) are loose inthe holder.
Cutting equipment
34
504 90 00-02
4 mm
504 90 00-01
6 mm
9 Cutting equipment
Remove the screws holding thecutting equipment and lift off thecutting equipment.
Remove the gear assembly as asingle unit.
NOTE!The nuts on the eccentric cams haveleft-hand threads. The connecting rodhas a needle bearing on the big end,exercise great care so that it does notfall apart. The needles lie loosely in theholder.
Remove the nuts holding the eccentriccams.
Remove the lower eccentric cam,washer, upper connecting rod, uppereccentric cam, and the gear from theaxle.
If the small gear is damaged or thebearing for the clutch drum’s gear axleis to be replaced, then the gearboxmust be removed from the engine.
Remove the clutch drum’s screw,washer and the clutch drum. Counterhold using the hexagon grip on the endof the axle.
When replacing the bearing, heat thehousing using a hot air gun beforeremoving and inserting.
Bearing clutch drum 32 mm, punch502 71 35-01.
Bearing gear assembly upper 22 mm,punch 502 50 30-13
35
503 98 96-01
503 98 96-01
9
Turn the upper connecting rod withthe pin from the gear towards you.
Fit the washer.
Fit the lower eccentric cam. The lower eccentric cam is displaceda 1/2 turn in relation to the uppereccentric cam.
Fit the left-hand threaded nut. Tight-ening torque 30 Nm.
Fit the clutch drum’s gear, clutchdrum, washer and screw. Secure thescrew using weak thread lock fluid.Tightening torque 12 Nm.
Thread the axle in the gear.
Fit the upper eccentric cam.
Fit the upper connecting rod.
Assembling the gearbox
325HS75, 325HS99:
Lubricate the components withgrease 503 98 96-01 whenassembling.
Fit the gear assembly.
Fit the cutting equipment.
Fit the support plate.
Guide in the connecting rod’s pin inthe blade and fit the cuttingequipment’s screws.
Tighten the lock nuts. Counter holdthe screws inside the gearbox.Check that the cutting equipment’swasher moves. If the washer does notmove loosen the hexagonal screwmax. a 1/4 turn.
Turn the lower connecting rod so thatthe pin fits in the cutting unit.
Fit the lower connecting rod.
Fit the felt seal.
Fit the flat washer on the gearassembly’s axle.
Fit the thrust washer on the gearassembly’s axle.
Fit the guide plate.
Fill the angle gear with 1 1/2 tubes ofgrease 503 98 96-01.
Check that the cover’s O-ring seal isin the right position and fit the cover.
Secure the O-ring seal with grease.Hold the cover with your thumb.Tighten the screws on the covercrosswise.
Cutting equipment
NOTE!The connecting rod has a needlebearing on the big end, exercisegreat care so that it does not fallapart. The needles (53) are loose inthe holder.
36
!
9
40° 36°
36°
325HS
325HDA55/325 HE
6 mm
504 90 00-01
4 mm
504 90 00-02
It should be possible to turn the clutchdrum around with one finger.
Make sure the blades work correctlywhen the clutch drum is rotated.
Dismantling the cuttingunit
WARNING!The blades are sharp, risk for injuriesto the hands. Wear protective gloves
325HS75, 325HS99:
Remove the lock nuts.
Remove the screws.
Remove the guard plate and twoblades from the bar.
Sharpening the blades
325HDA55, 325HE3, 325HE4
325HS75, 325HS99:
The blades can be carefully groundusing a handheld grinding machine.Try to reproduce the edge angles asillustrated.
Assembling the cuttingequipment
325HDA55, 325HE3, 325HE4
325HS75, 325HS99: NOTE!Turn the blades correctly whenassembling.
Place the bar flat on the bench withthe plain holes to the right.
Place the blades edge-to-edge on thebar and (for 325HS) with the teethfacing away from you.
Fit the guard plate in the outersecuring screw’s hole. Turn the longpart outwards (only 325 HS).
Fit and tighten the securing screwswith washers as normal, no washer bythe guard plate on 325 HS.
Fit the lock nuts.
Loosen the screws a 1/4 turn andcheck that the washers can move.
Counter hold the screws and retightenthe lock nuts.
Check that the blades move easily.
Cutting equipment
325HDA/325HE:
The blades can be moved using a 4mm allen key in the axle’s key socket.
325HS:
The blades can be moved using a 6mm allen key through the hole in theunderside of the gearbox cover.The angle 40° is excluded on modelswithout top grinding.
Wear protective glasses whengrinding the blades.
WARNING!
37
9
Fitting the cuttingequipment
325HS75, 325HS99:
See assembling the gearbox above.
Fitting the gearbox
325HS75, 325HS99:
Hold the cables in place with a finger,fit the engine and makes sure that nocables are pinched.
Tighten the engine.
NOTE!The cables will be damaged by theflywheel if routed incorrectly.
Position the short-circuit cable in thecut-out in the gearbox.
Place the ignition cable in cut-out inthe gearbox.
Check that the clip set is in positionon the gearbox.
Fit two rubber supports for the tank onthe gearbox.
Fit the tank, guide onto the rubbersupports, press into position.
Cutting equipment
38
9Thread two rubber supports on top ofthe tank.
Fit the starter. Pull the starter handle a little so thatthe starter falls into place and posi-tion the screw by the starter handle tosecure.
Fit the heat guard with a screw.
Fit the handle on the frame. Turn the handle’s screw so that the nutis against the tank. The nut’s flat sideagainst the handle.
Cutting equipment
39
504 90 00-04
3 mm
504 90 00-02
4 mm
9Check that the ignition cable is routedcorrectly so it cannot be damaged bythe flywheel.
NOTE!Risk for incorrect assembly.
If the wrong screw is placed in thehole closest to the gearbox thethreads in the clip set will be crossed.
Fit the cylinder cover.
Align the cylinder cover with the slot forthe screw head, make sure that whenthe cover is moved down that theignition cable is secured by the wedgeshaped cut-out in the cylinder cover.
Fit the thick threaded screw (for the clipset) in the hole closest to the gearbox.
Fit the remaining screws for thecylinder cover and tighten the screwson the starter, heat guard and cylindercover.
Changing the frontsprings
325HS75, 325HS99:
Remove the 3 screws holding thesprings in the frame and wear plate.
Unscrew the spring from the gearbox.
Replace the front support spring.
Remove the screw located in the wearplate.
Remove the screw located in the frame.
Changing the rearsprings
325HS75, 325HS99:
Remove the 3 screws holding thesprings in the frame and wear plate.
Remove the 2 screws holding the rearsprings in the gearbox.
Slide the frame backwards so you cangain access to remove the 2 screwsholding the springs on the frame.
Use pipe grips on the first spring turnwhen removing the spring otherwisethe spring will self-lock in themounting.
Cutting equipment
40
41
42 ´*3'@¶6'¨
43
44 ´*3'@¶6'¨ 2001W03 101 90 73-26
