Husqvarna K 960, Workshop Manual

Page 1: ...HUSQVARNA CONSTRUCTION PRODUCTS Workshop manual K 960 ...

Page 2: ...ES 5 5 STARTER 9 6 IGNITION SYSTEM 12 7 FLYWHEEL 15 8 AIR FILTER 17 9 INLET SYSTEM 18 10 FUEL SYSTEM 20 11 CARBURETTOR 23 12 DECOMPRESSION VALVE 28 13 CYLINDER PISTON 29 14 CRANKCASE 35 15 CLUTCH 40 16 CUTTING HEAD 44 17 FRICTION RETARDER 49 18 HANDLE 51 19 TOOLS 52 CONTENTS Page HUSQVARNA K 960 502 53 07 26 ...

Page 3: ...ng the speci fic service work Layout pictures and text Besides the pictures and illustrations there is generally two columns of text The left hand text column is a concise and is suitable for experienced mechanics the right hand column gives a more detailed description and is targeted at mechanics with less experience of repair work on the power cutter Contents The manual is divided into numbered ...

Page 4: ...no logy to about half compared with a tradi tional design The emission values are now well below levels in the regulations from EPAII The output is higher over the entire speed range and the torque in the lower speed range is now significantly higher Lower vibration levels The fuel tank is integrated in the handle unit which means lower handle vibrations through the greater weight A redesigned vib...

Page 5: ...tank 8 Starter handle 9 Starter 5 4 1 2 3 6 8 9 10 11 12 13 14 17 18 19 15 7 16 21 20 10 Combination spanner 11 Belt adjustment screw 12 Lock screws for belt adjustment 13 Cutting arm rear belt guard 14 Throttle control 15 Rear handle 16 Throttle trigger lock 17 Water valve with tool attachment 18 Water connector 19 Choke Lever 20 Start throttle lock 21 Stop switch ...

Page 6: ...ctive chapters Cutting head 1 Loosen the screws on the cutting head 2 Slacken off the belt tension using the adjuster screw Dismantle the screws on the cutting head 3 Dismantle the front belt cover by sliding it forwards 4 Loosen the hoses by the water valve Lift off the belt from the pulley and remove the cutting head 5 Loosen the two screws on the rear belt guard Tightening torque when assemblin...

Page 7: ... it to the side and removing it from its bracket 1b Removed the throttle rod from the throttle and dismantle from the carbu rettor 1c Pull off the fuel hose from the carbu rettor 2 Remove the first screw holding the carburettor on the crankcase 3 Now insert the Torx key through the hole in the handle and loosen both screws holding the carburettor on the inlet manifold 1 2 3 1 1 2 a b c 5 2 4 3 4 R...

Page 8: ...filter unit cylinder cover starter air duct and car burettor The cylinder must be lifted slightly to replace the inlet manifold between the carburettor and cylinder See the detailed description on page 21 Assembly 6 Pre assemble the components as illustrated Slide the screws slightly past the contact face 7 Note the partition wall in the inlet manifold Note that the marking UP must face upwards if...

Page 9: ...mpers can be replaced on a complete machine as described below in the section Actions for replacing Splitting the machine Dismantle the outer screws on the vibra tion dampers 1 Behind the machine s ground support Actions for replacing The machine must be split as described above Dismantle the muffler too 2 Below the flywheel Actions for replacing Dismantle the star ter 3 The handle loop by the cyl...

Page 10: ...and then out through the notch for the cord Pull out virtually the whole cord length until sufficient cord remains to tie a knot as illustrated 2 Insert the other end through the cover and on through the handle Tie a double knot as illustrated Loading the return spring 1 Fit the starter cord in the cut out 2 Wind the starter cord 4 turns around the hub 3 Pull out the starter handle so the cord rol...

Page 11: ...oil on the spring Starter pulley 1 Dismantle the centre bolt and lift off the starter pulley Clean the surfaces between the starter pulley and the spring cassette Assembly 2 Lubricate the hub with grease arrows Preferably also apply some grease around the starter pulley hub so that the grease seals against the spring cassette 3 Align the starter pulley cut out with the end of the spring when assem...

Page 12: ... screw Note the position of the springs in relation to the flanges on the flywheel so that they are fitted correctly NOTE Do not forget the washer A that should lie under the starter pawls against the flywheel Assembly It is important that the spring does not get caught between the starter pawls and the flywheel The following method is recommended when assembling 1 Press the spring into position i...

Page 13: ...h induction At the same time a high voltage approximately 20 000 volt is transformed in the secondary coil to the spark plug Electronic circuit breaker STOP control Volts 0 Ignition point S N S N 1 1 A D B C 2 2 3 3 Ignition module Individual components can not be replaced The ignition lead contact unit to the spark plug and seals on the ignition module can be replaced The short circuit contact ar...

Page 14: ...his 3 Insert a pair of pointed pliers in spark plug connection and pull out the spring and cable end 4 If the connection is defective the igni tion lead can be shortened slightly Make a new hole in the cable with a awl and fit the connection spring 5 The adjoining simple connection can be used to check that the ignition lead is not broken The battery is connected in series with a test lamp Alterna...

Page 15: ...wards the ignition module Place air gap gauge 01 in 0 3 mm 502 51 34 02 against the magnets and fit the new module in position The screws should be tightened to a torque of 6 6 8 1 lbf ft 9 11 Nm Test the short circuit cable and stop switch Test using a measurement instrument or the following simple solution Connect a battery in series with a test lamp to the short circuit cable and engine body Wa...

Page 16: ...r starter pawls Dismantle the centre nut Use the handle on the special tool to lock the rotation of the flywheel and dismantle the nut and washer Dismantle the nut Press off the flywheel Fit the screw puller in the centre and screw it down as far as necessary to get a secure fitting in the plate Hold the large nut and screw in the centre bolt until the flywheel releases Tip If the flywheel is very...

Page 17: ...ight placement in relation to each other Only the force of the centre nut is not sufficient to hold the flywheel in the right position Fit the flywheel The crankshaft and the centre of the flywheel must be free from grease when assembling Align the key in the flywheel with the keyway on the crankshaft Fit the washer and centre nut Tightening torque 18 22 lbf ft 25 30 Nm Use a torque wrench to tigh...

Page 18: ...is better utilised and is fouled evenly across the surface The filter is steeped in oil and is made up of three layers with different pore sizes 3 The paper filter primarily provides effective protection should the foam plastic filter on account of inadequate care lets dust through Filter service 1 Centrifugal cleaning The inlet duct should be inspected and any deposits removed in connection with ...

Page 19: ...se 5 Dismantle the four screws on the base of the cylinder and lift up the cylinder slightly At the same time turn the fly wheel to the piston s upper turning point to keep the piston rings in the cylinder 5 Dismantle the four screws on the base of the cylinder and lift up the cylinder slightly 3 Lift off the ignition lead 4 Dismantle the screws on the crankcase 1 2 3 4 5 Dismantling Dismantle the...

Page 20: ...ress the rubber bellows out of the holder and dismantle the metal plate Replacing the rubber bellows 9 Dismantle the partition wall 10 Press the rubber bellows out of the holder and dismantle the metal plate Parts must face the right way Correct assembly of the components is evident from the pictures Make a special check to ensure the impulse channel is open Parts must face the right way Correct a...

Page 21: ... not cracked or in any other way defective Fouled filters are replaced with new ones Leakage testing Pressure tester 501 56 27 01 Use the pressure tester 501 56 27 01 to test the tightness of the fuel system The pressure tester is supplied with an adapter for small hose sizes this should be used on the fuel hose Make the hose between the adapter and the pressure tester as short as possible Leakage...

Page 22: ...he fuel system s hoses Split the machine at the vibra tion dampening element Note the fuel system hoses assembly order Exclude the carburettor as the cause of the leakage Plug the hose by the carburettor and redo the pressure test If the hose is intact the carburettor must be checked Exclude the carburettor as the cause of the leakage Plug the hose by the carburettor and redo the pressure test Non...

Page 23: ...s simply checked by blowing though the hose Tank venting hole Check by blowing through the hose Tank venting hoses The locking pin must be dismantled to remove the hose to the tank Pull it up using a pair of pliers Now pull out the hose together with the nipple from the tank Tank venting hoses Pull up the locking pin Pull the hose out of the tank 10 22 ...

Page 24: ...rottle rod for the choke 4 Fuel line 5 Impulse channel from the crankcase to the carburettor s pump diaphragm 6 Choke valve 7 Duct for pressure equalisation against the filter chamber SmartCarb 8 High and low speed jets set at factory 9 Idle screw speed adjustment 10 Pump unit cover 11 Measurement chamber cover 12 Pump diaphragm top in connection with the crankcase via the impulse duct fuel under ...

Page 25: ...s fuel pipe Pump up the pressure to approximately 200 kPa and let the fuel run out through the venturi Not until air emerges from the venturi can the function of the needle valve be tested as set out below If the needle valve does not open at 250 kPa max permitted pressure test the needle valve has jammed This can usually be forced open by blowing gently through the hole for filter compensation A ...

Page 26: ...ls against the needle valve should be replaced Always replace in uncertain cases See the needle valve as a wear part that needs to be replaced during the life of the machine The picture shows a new needle tip Inspect the tip of the needle with a magnifying glass If there are signs of deposits or the tip of the needle is deformed it must be replaced The picture shows a new needle tip Clean the seat...

Page 27: ...e valve flaps closed tightly against the carbu rettor housing Fuel strainer There is a fine meshed strainer located on the fuel inlet to the carburettor Inspect this with a magnifying glass Loose dirt particles can be blown away from the needle valve s seating If there are depo sits that are hard to remove or the mesh is damaged the strainer must be replaced The strainer is dismantled using a need...

Page 28: ...f approximately 2700 rpm The blade should not rotate at this speed If the blade rotates lower the speed a little If this does not help the clutch should be rectified Adjust outdoors The blade should be fitted Run the machine warm for approximately 5 minutes Align the arrow towards the spark plug Adjust to an idle speed of approximately 2700 rpm If the blade rotates lower the speed a little If this...

Page 29: ...ion and slowly pull the starter handle while observing the decompression valve Decompression valve Function The decompression valve reduces the compression in the cylinder when starting A limited quantity of fuel air mixture leaks out through the decompression valve as shown in fig A As soon as the engine fires the valve will close due to the combustion pressure as in fig B A B Dismantling Dismant...

Page 30: ...r and is diffi cult to start this may be due to poor compression Close the decompression valve or fit the sealing plug 503 55 22 01 to eliminate the decompression valve as the source of the fault 503 55 22 01 531 03 16 86 Compression tester The compression test is performed using the measurement instrument 531 03 16 86 which is connected to the spark plug hole The valve below the gauge evacuates t...

Page 31: ...tween the piston and the crankcase to facilitate the work Tool kit 502 50 70 01 The tool kit contains piston ring compressors a piston stop and a support plate for the piston The piston stop must not be used on K960 Remove the cylinder base gasket 502 50 70 01 Seal with a cloth or paper so as not to risk anything falling down into the crankcase Seal with a cloth or paper so as not to risk anything...

Page 32: ... it away from you so it can be lifted out of the groove at the rear edge Assemble the parts in the reverse order Piston rings Dismantle the piston rings Important when assembling The piston ring groove has a guide pin that prevents the piston rings from rota ting Fit so that the open part of the piston ring aligns with the guide pin Turn the piston ring with the bevelled edge towards the guide pin...

Page 33: ... wear If the piston has been worn com pletely smooth by the ports you should consider replacement Piston ring groove Measure the piston ring groove using feeler gauges If the piston ring groove is greater than 06 in 1 6 mm the piston must be replaced Fit a complete piston kit with piston rings needle bearing and gudgeon pin Piston ring groove If the piston ring groove is greater than 06 in 1 6 mm ...

Page 34: ...es that the machine works at short intervals and has not been run completely warm Scoring Damage of this type is always the result of overheating The cores are usually on the exhaust side which is the hottest Inlet side can show similar damage Check whether the machine has broken down due to an incorrect oil mixture or no oil at all The oil on the overheated piston has probably carbonized Check in...

Page 35: ...connect with the gasket Fit the gasket on the cylinder Cylinder base gasket Carefully clean any old gasket residue from the surfaces Fit the gasket on the cylinder Assemble the cylinder Check that the opening on the piston rings align with the guide pin Assemble the cylinder Check that the opening on the piston rings align with the guide pin Press together the piston rings using a suitable piston ...

Page 36: ...ng disc with screws size M4 x 20 mm with washers Exhaust port 4 Dismantle the cutting head and the muffler as set out on page 5 and 7 Assemble the sealing disc with the screws used for the muffler Sealing plug 5 Fit the sealing plug 503 55 22 01 in the hole in the cylinder for the decompression valve Test for leakage Connect the pressure tester to the nipple on the inlet seal Pump a pressure to 50...

Page 37: ... flywheel side Assembly CLUTCH SIDE 1 Lubricate the assembly taper and place on the axle 2 Press down the sealing ring over the taper and down towards the seating 3 Knock down the sealing ring into its seating with the assembly punch Assembly FLYWHEEL SIDE 1 Lubricate the axle The assembly taper is not used 2 Press the sealing ring against the seating 3 Knock down the sealing ring into its seating...

Page 38: ... grip plate 544 06 00 02 and press out the crankshaft with the puller Press out the crankshaft from the other crankcase half in the equivalent manner Connecting rod Check that there is no radial play on the connecting rod by the crankshaft journal If this is the case the whole unit must be replaced Clean the gasket surfaces Carefully clean the gasket surfaces No gasket residue must remain Filled b...

Page 39: ...ol kit against the bearing and knock this out with a large plastic mallet Assembly Use the tool kit 506 37 61 02 for bearing assembly in both crankcase halves Place the bearing on the support plate and hold it under the crankcase half Insert the screw through the washer and fit the screw in the support plate Lock the screw and turn the nut until the bearing reaches the stop in the crank case half ...

Page 40: ...nkcase half Make sure that the connecting rod is not held against the crankcase half Picture 5 Fit the guides Picture 6 Fit the new crankcase gasket Picture 7 Assemble the other crankcase half using the same method as the first Change to the other threaded mandrel IMPORTANT Pay attention to the position of the connecting rod while tightening so that this does not get jammed in position Also align ...

Page 41: ...must be rectified if the blade starts to rotate at an engine speed below 3100 rpm Clutch shoes The height of the clutch shoe s bevelled section should not be less than 04 in 1 mm Replace if necessary for the complete clutch Never replace individual shoes from another clutch this creates imbalance Clutch drum The inside diameter of the clutch drum must not exceed 3 14 in 79 8 mm Replace if necessar...

Page 42: ... Dismantling Use a universal puller Assembly The support ring is assembled using the tool intended for assembling the crank shaft in the crankcase 544 10 36 02 Fit the piston stop Position the support ring on the shaft and position the tool as illustrated First screw down the tool s centre screw left hand thread so that it grips fully on the threads of the clutch Assembly Fit the piston stop Place...

Page 43: ...he clutch bearing with the help of socket 29 32 in 23 or 24 mm M8 screw approximately 3 4 in 80 mm and nut washer outside diameter slightly smaller than 3 4 in 19 mm washer diameter approximately 1 1 4 16 in 25 30 mm Bearing replacement needle bearing For a long time a clutch drum with needle bearing has been the standard design on Husqvarna petrol driven power cutters The needle bearing is lubric...

Page 44: ...he ball bearing mounted clutch must also have a washer between the clutch drum and clutch Tools The tool kit 504 56 79 01 is needed to replace the ball bearing of the clutch drum Use the tool to dismantle and fit the bearing as described below The tool kit consists of a support plate for the bearing A the sleeve B and the cover C Note that the cover has different profiles one side to match the sle...

Page 45: ...nners Now remove the inner flange washer Press up bushing with two open ended spanners Now remove the inner flange washer Remove the spacer together with the bearing seal Check that the seal is intact Dirt under this indicates defective seals and these should be replaced Remove the spacer together with the bearing seal Check that the seal is intact The washer and the three screws hold the blade gu...

Page 46: ...Tools To replace the blade shaft bearing a special tool is needed 506 37 61 02 Use the tool both for dismantling and assembly The tool s round threaded plate is the support plate for the bearing that is to be fitted Use the plate with the smaller diameter for the K960 Use the round chamfered washer when assembling the inner bearing Use the triangle when assembling the outer bearing Here the triang...

Page 47: ...xle and knock the axle out of both bearings Alternatively a brass punch can be used to drive out the axle Split the bearing unit Use the vice as a counterhold Fit the screw on the special tool in the axle and knock the axle out of both bearings Alternatively a brass punch can be used Check Check that the axle and the bearing seating in the cutting arm are not damaged If the bearing is seriously da...

Page 48: ...ng fitted first Pull in the outer bearing until the spacer ring touches 1 Assembling the axle First check that the spacer ring between the bearings is centred The following procedure gives good results Turn the triangle with the smooth side facing downwards Hold the axle on its underside and screw in the screw of the tool along with the large washer Note that the triangle lies directly against the...

Page 49: ... the position as per paragraph 3 above Bearing housing blade guard Check that the rubber seal is fitted properly against the bearing housing and blade guard Turn the bearing housing so that the screw hole becomes accessible from the top with the tool Tighten the three screws crosswise so that the washer is not unevenly loaded and risks being deformed Tighten the screws fully Fit the seal with spac...

Page 50: ...ly assembled parts that are held together by the spring In the event of replacement replace the entire unit as in the picture The brake drum is fitted against the bearing housing with three screws The centrifugal unit is secured against the belt pulley with four screws Dismantling Procedure To be able to handle the friction retarder as a single coherent unit it is important that dismantling and as...

Page 51: ...rrectly against the bearing housing Fit the three screws Assembly of the centrifugal unit Normally the unit is handled without dismantling it If needed carry out assembly of the parts in the following manner 1 Place the spring in position in the guide plate Note where the spring ends should be located 2 Locate the brake drum in its position 3 Assemble the brake shoes by stretching the spring with ...

Page 52: ...l the lock on top of the handle is pressed in should the throttle be re leased Faulty function must be rectified The machine must be split at the vibration dampening element to perform service work on the control The spring should lie on the right hand side clutch side of the throttle lock pin Lower the control parallel with the handle Assemble the spindle from the right hand side Assembly Fit the...

Page 53: ...ng the maximum speed 501 56 27 01 Pressure tester Test of carburettor functionality Test of fuel lines Test of non return valve in the tank ventilation 502 50 70 01 Kit for piston service Consisting of piston ring com pressor piston stop and support plate Use piston stop 504 91 06 05 for K950 Piston service 504 91 06 05 Piston stop Locks the crankshaft s rotation Dismantling the clutch 531 03 06 2...

Page 54: ... 02 544 06 00 02 Grip plate Splitting the crankcase in com bination with 504 90 90 02 531 00 48 67 Bearing puller Dismantling the main bearing from the crankshaft 544 10 36 02 Bearing press Dismantling the main bearing Assembly of the crankshaft Assembly of the clutch s support washer on the crankshaft 502 50 83 01 Hose catcher Tool for catching the fuel hose in the tank and drawing out the fuel f...

Page 55: ...www husqvarnacp com 502 53 07 26 English 2007 09 ARNE PALMQUIST ...