Husqvarna 525P4S Workshop Manual

Husqvarna 525P4S Workshop Manual

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Workshop Manual
525P4S 525P5S 525PT5S


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Summary of Contents for Husqvarna 525P4S

  • Page 1 Workshop Manual 525P4S 525P5S 525PT5S English...
  • Page 3: Table Of Contents

    Service data ............15 Safety equipment ..........24 Repair instructions ..........28 Troubleshooting ............. 78 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 Saw head, dismantling (PT5S) ......65 Air filter, dismantling and assembling ....36 Saw head, assembling (PT5S) ......67 Saw head, dismantling (P4S and P5S) ....74 Saw head, assembling (P4S and P5S)....77 Service data ............15 Carburetor ............37 Shaft, dismantling (P4S and P5S) ......
  • Page 5 Index English -...
  • Page 6: Introduction And Safety Instructions

    Introduction and safety instructions 2 Introduction and safety instructions Contents General ...........................7 Safety ..........................7 Target group ........................7 Modifications ........................7 Tools ..........................7 Structure .........................7 Numbering ........................7 General instructions ......................8 Special instructions ......................8 2.10 Symbols on the machine ....................9 2.11 Symbols in the Workshop Manual ..................9 - English...
  • Page 7: Introduction And Safety Instructions

    2.5 Tools Special tools are required for some stages. All service tools are listed in the Workshop Manual. Usage is made apparent in each section. Always use Husqvarna’s original: • Spare parts • Service tools • Accessories English -...
  • Page 8 Introduction and safety instructions 2.8 General Instructions 2.9 Special Instructions The workshop where the machine is to be repaired The fuel used in the machine has the following must be equipped with safety equipment in accord- hazardous properties: ance with local regulations. • The fluid and its vapour are poisonous.
  • Page 9: Symbols In The Workshop Manual

    Introduction and safety instructions 2.10 Symbols on the machine 2.11 Symbols in the Workshop Manual The symbols below are embedded on the machine This symbol warns of personal injury Choke control when the instructions are not followed. Use protective gloves. Refuelling Use protective goggles.
  • Page 10: Technical Data

    3 Technical data Displacement Cylinder diameter Stroke length Max. output/speed cm3/cubic inch Ø mm/Ø inch mm/inch kW/rpm 525P4S: 25,4/ 1,55 34 / 1.34 28 / 1,10 1,0 / 8500 525P5S 25,4/ 1,55 34 / 1.34 28 / 1,10 1,0 / 8500...
  • Page 11 Technical data 3 Technical data Engage speed Spark plug Volume fuel tank Litre/US. pint 525P4S: 4000 (+/- 200) NGK BPMR8Y 0,51/1,08 525P5S: 4000 (+/- 200) NGK BPMR8Y 0,51/1,08 525PT5S: 4000 (+/- 200) NGK BPMR8Y 0,51/1,08 Weight without fuel kg / lbs...
  • Page 12: Engine Special Tools

    Engine special tools 4 Engine special tools Contents Special tools ........................13 - English...
  • Page 13 Engine special tools 4.1 Special tools Removal bolt For shaft (open) English -...
  • Page 14 Engine special tools Description Used for Order No. Torx wrench General disassembly / assembly tasks 578 28 90-01 Air gap tool (t 0.3mm) Adjust the air gap when installing the 514 22 10-01 ignition module Stopper (14 mm use) Fix piston in place when installing / 514 24 39-01 removing clutch, rotor and starter pulley.
  • Page 15: Service Data

    Service data 5 Service data Note! Lubricate with two-stroke oil. Some of the screws are captive screws Lubricate with Grease and will remian into the cover. Apply thread lock: Three bond or loctite Tighten torque in Nm English -...
  • Page 16 Service data - English...
  • Page 17 Service data 15,0 English -...
  • Page 18 Service data 525PT5S 8-10 8-10 - English...
  • Page 19 Service data 525PT5S English -...
  • Page 20 Service data 525P5S, 525P4S 4±1 10±2 8-10 - English...
  • Page 21 Service data 525P5S English -...
  • Page 22 Service data 525P4S - English...
  • Page 23 Service data English -...
  • Page 24: Safety Equipment

    safety equipment 6 Safety equipment Content Dismantling the muffler ....................25 Assembling the muffler ....................25 Dismantling the stop switch ...................25 Assembling the stop switch ....................25 Resistance test - stop switch ..................26 Dismantling throttle......................26 Assembling the throttle ....................27 - English...
  • Page 25: Muffler, Dismantling

    Safety equipment 6.1 Dismantling the muffler Remove the cover of the muffler. Dismantle the two screws to the muffler. Also remove the gasket. 6.2 Assembling the muffler Check the muffler, and if you find any deformation or cracks replace the muffler. If the muffler is fitted with a spark arrestor mesh, put it in place first.
  • Page 26: Stop Switch, Resistance Test

    Safety equipment 6.5 Resistance test - stop switch Dismantle the stop switch as outlined. Clean the contact areas. test the resistance by connecting a multimeter to the stop switch. The resistance should be as fol- low: ”0” pressed in - less than 0.1 Ω. ”1”...
  • Page 27: Throttle, Assembling

    Safety equipment Check that the throttle cable is fitted to the under- side of the pin on the throttle trigger lock. 6.7 Assembling the throttle Put all details in the left half of the handle. Make sure that the spring is correct fitted. Make sure that all cables is fitted in the handle and will not be clamped.
  • Page 28: Repair Instructions

    Startapparat 7 Repair instructions Content Dismantling the recoil pulley...................29 Assembling the recoil pulley...................29 Replacing the starter pawls ....................31 Checking the ignition spark ....................32 Dismantling the shaft and clutch housing from engine body ..........34 Assembling the shaft and clutch housing from engine body ..........34 Adjust the air gap when installing ignition module............35 Fuel system ........................36 Dismantling and assembling the air filter ................36...
  • Page 29: Starter Recoil Pulley, Dismantling

    Repair instructions 7 Repair instructions 7.1 Dismantling the recoil pulley Remove the 3 screws and lift off the starter Remove the inner cover in the starter housing. Use a flat screw driver or similar tool. WARNING! Wear protective glasses. The return spring lies tensioned in the starter and can fly out and cause personal injury with careless handling..
  • Page 30 Repair instructions Lubricate the spindle with a little grease and fit the starter pulley. Tighten the screw. Assemble a new starter cord. Slide it into the starter pulley’s slot as illustrated and then out through the cord guide in the starter housing. Make sure the knot on the end of the cord is as small as possible! NOTE!
  • Page 31: Start Pawls, Replacing

    Repair instructions 7.3 Replacing the starter pawls Fit the piston stop(A), no. 514 24 39-01 in the spark plug hole and loosen the starter pulley using special tool 581 96 55-01 (B). Remove the circlip holdings the starter pawls. Lift out the starter pawls and spring for replace- ment.
  • Page 32: Ignition Spark, Checking

    Repair instructions 7.4 Checking the ignition spark Dismantle the cylinder cover after the guard over the muffler and the air filter has been removed. Earth the spark plug on the cylinder and pull sharply on the start handle. A spark should be seen between the electrodes. If no spark is seen test with test spark plug no.
  • Page 33 Repair instructions Fit the spark plug cap onto the ignition cable and make sure the ends of the wire is inserted into the centre of the spark plug cap for best contact. TIP! Lubricate the hole in the spark plug guard using for instance silicon spray to make it easier to push the ignition coil in.
  • Page 34: Dismantling The Shaft And Clutch Housing From Engine Body

    Repair instructions 7.5 Dismantling the shaft and clutch housing from engine body Remove the cylinder cover, guard over the muffler, and the air filter. Unhook the throttle cable from the carburetor and insulator. Disconnect the cables from ignition module. Remove the screws holding the clutch housing on the engine.
  • Page 35: Ignition Module, Adjusting

    Repair instructions 7.7 Adjust the air gap when installing the ignition module Adjust the air gap as needed to the correct value. • Loosen the bolts. • Position the gauge to adjust the gap and press the ignition module against the flywheel. • Tighten the bolts and check the air gap again. If the spark plug still does not fire, the ignition system should be replaced.
  • Page 36: Air Filter, Dismantling And Assembling

    Repair instructions 7.8 Fuel system In addition to the fuel tank and carburetor, 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.
  • Page 37: Carburetor

    Repair instructions 7.11 Replacing the fuel filter The fuel hose in the tank contains a fuel filter. It is accessible through the fill hole. Pull out the filter with your fingers or with help of tool 502 50 83-01. If the filter is not too dirty, its surface can be cleaned with a brush.
  • Page 38 Repair instructions The carburetor’s design The carburetor can be divided into three different functional units: the metering unit, the blending unit, and the pump unit The metering unit The needles (A) and the fuel control functions are located here. The needle valve (B) and control diaphragm (C) are vital to the carburetor’s function.
  • Page 39: Carburetor, Dismantling

    Repair instructions 7.14 Dismantling the carburetor Carefully remove the metering diaphragm (A) and gasket (B). Check the diaphragm for holes and wear on the pin (C). Replace the diaphragm if required. Connect pressure tester 531 03 06-23 to the fuel hose nipple.
  • Page 40 Repair instructions Check the needle valve for damage on the tip (D) and in the lever arm groove. (E) Check the lever arm for damage to the groove (F) for the needle valve and wear on the mounting points towards the control diaphragm (G). Replace damaged components with new ones.
  • Page 41 Repair instructions Unscrew the jet needles. Make sure they are clean and not damaged on the tip of the needle. NOTE! Note how the jets are positioned. (For example, the H-needle is a little shorter than the L-needle). Press out the main jet (A) with a suitable punch. Remove the plug (B).
  • Page 42: Carburetor, Assembling

    Repair instructions 7.15 Assembling the carburetor • Blow all channels in the carburetor compart- ment clean Groove • Mount a new plug (A). Use a suitable punch to get a completely tight seal. • Press in a new main jet (B). 45° • Mount the valves and springs. Tip! Any numbers on the valves should be able to be read from the outside. Make sure valves has a perfekt seal by locking at the edge of the valve with tha carburetor backlit, a light from the choke side.
  • Page 43 Repair instructions Attach the various parts of the measuring unit in the reverse order as set out for dismantling. The lever arm height should be 0,66 mm +-0,16 mm under carburetor housing plane. Too high setting = too much fuel. Too low setting = too little fuel.
  • Page 44: Carburetor, Settings

    Repair instructions 5. Connect the throttle cable on the carburetor with the help of flat nose pliers. Check that the cable sits correctly in the guide on the clutch housing (A) and that it sits correctly in the cut-out (B) of the insulator.
  • Page 45 Repair instructions Basic setting With a trimmer head (Use Husqvarna T35 trimmer head with silent cord The carburetor is set to its basic setting when test ∅ 2.4 mm. The length of the trimmer cord will be run at the factory. The basic setting is “richer” than...
  • Page 46: Centrifugal Clutch, Dismantling

    Repair instructions 7.17 Dismantling the centrifugal clutch, flywheel and ignition module Remove the engine cover, clutch housing and spark plug. Screw the stopper (special tool A) into the plughole to fix the piston in place.Stopper 14 mm 514 24 39-01. Remove the two screws holding the ignition module and take away the earth cable.
  • Page 47 Repair instructions Take out the flywheel nut (A). Rotor nut width across flats (WAF) M8 (WAF 12 NOTE! Slowly turn the rotor counterclockwise, and after applying the stopper (special tool) lightly to the piston head, loosen the nut. The piston head could be dama- ged if force is applied too sharply when loosening the nut.
  • Page 48: Centrifugal Clutch, Assembling

    Repair instructions 7.18 Assembling the flywheel, ignition module and centrifugal clutch When setting the key on the crankshaft, make sure the end face of the key is parallel with the crankshaft. Fix the piston in place with the stopper (special tool) and tighten the rotor nut.
  • Page 49: Cylinder And Piston, Dismantling

    Repair instructions Place the ignition module in position and fit the screws. Do not tighten the screws. Make sure the gap is: 0,3 mm Tighten the bolts while pressing the ignition module the flywheel. Assembly the sparkplug, all covers and the clutch covers with shaft.
  • Page 50 Repair instructions Pull the cylinder straight up without turning it. There is a risk that a piston ring may break. Remove the piston pin circlips. Use small flat nose pliers and remove the piston pin circlips. TIP! Keep your thumb over the circlip to prevent it from flying out.
  • Page 51: Cleaning And Inspection

    Repair instructions 7.20 Cleaning, inspection After dismantling, clean the individual components: Scrape carbon deposits from the top of the piston. Scrape carbon deposits from the cylinder’s combustion chamber. Scrape carbon deposits from the cylinder’s exhaust port. NOTE! Scrape carefully off soot deposits using a not too sharp tool so as not to damage the soft aluminium parts.
  • Page 52 Mixing ratio: 1:50 (2%). If Husqvarna two-stroke oil is not available another good quality two-stroke oil can be used. Mixing ratio: 1:33 (3%) or 1:25 (4%). - English...
  • Page 53 Repair instructions Piston scoring caused by heavy carbon deposits Too heavy carbon depositing can cause damage similar to that caused by insufficient lubrication. However, the piston skirt has a darker colour caused by the hot combustion gases that are blown past the piston. This type of piston damage starts at the exhaust port where carbon deposits can become loose and get trapped between the piston and the cylinder...
  • Page 54 Repair instructions Piston ring guide pin vibrated loose A too high engine speed can cause the ends of the piston ring to hammer against the guide pin when the piston ring moves in its groove. The intensive hammering can drive out the pin through the top of the piston causing serious damage also to the cylinder.
  • Page 55 Repair instructions Foreign objects Everything other than clean air and pure fuel that enters the engine’s inlet port causes some type of abnormal wear or damage to the cylinder and piston. This type of increased wear shows on the piston’s inlet side starting at the lower edge of the piston skirt.
  • Page 56 Repair instructions Larger, harder particles that enter the engine cause serious damage to the underside of the piston skirt. Cause: Action: Air filter damaged or Fit a new air filter. missing. Parts from the carbure- Regular service and tor or intake system inspection.
  • Page 57 Repair instructions Wear tolerances Cylinder bore When the surface coating is worn and aluminium appears Piston ring gap Max. 0,5 mm with the piston ring inserted in the lower part of the cylinder. Piston ring groove Max. 1,1 mm. Clean the groove before checking the measurement.
  • Page 58: Cylinder And Piston, Assembling

    Repair instructions 7.22 Assembling the piston and cylinder Clean the crankcase Fit the piston on the connecting rod so that the arrow on the piston points towards the exhaust port. Lubricate the piston pin’s needle bearing with a few drops of engine oil. NOTE! Place a rag in the crankcase opening to prevent the circlip from falling into the...
  • Page 59: Crankshaft, Dismantling

    Repair instructions 7.23 Dismantling crankshaft and crank- case The task of the crankshaft is to transform the reciprocating motion of the piston to rotation. This requires a stable design withstanding immense pressure and rotational and bending strain, as well as high rotational speed.
  • Page 60 Repair instructions nspect the small end of the connecting rod. If seizure marks or discolouration are found in the bearing track the crankshaft must be replaced. Check the crank bearing. The connecting rod shall not have any radial play (up and down). It should, however, have axial play, in order to ensure good lubrication of the crank bearing among other things.
  • Page 61: Crankshaft, Assembling

    Repair instructions 7.24 Assembling the crankshaft and crankcase Check the crankshaft as set out in the section ”Inspecting the crankshaft”. Fit the new bearing in the crankcase using a press tool. During press fit of the bearing don’t push the inner bearing to fit Assemble the piston on the crankshaft.
  • Page 62: Clutch Drum, Replacing

    Repair instructions 7.25 Replacing the clutch drum and drive shaft The centrifugal clutch has the task of transferring the power from the engine to the cutting equip- ment’s drive shaft. As the name implies, it works according to a centrifugal principle. This means the clutch’s friction shoes are thrown outwards towards the clutch drum at a certain engine speed.
  • Page 63 Repair instructions Remove the screw (A) and screw (B) that hol- ding the clamp connection for the shaft. Remove the two screws holding the clutch hou- sing cover. Pull apart the shaft from the clutch housing. English -...
  • Page 64 Repair instructions Remove the upper and lower clamp. Remove the anti vibrations element Note! replace the antivibration element if it is damaged or cracked. Remove the small circlip from around the shaft on the clutch drum using suitable circlip pliers. 515 41 95-01 Dismantle the clutch drum by using a specila tool, 581 44 10-01.
  • Page 65: Saw Head, Dismantling (Pt5S)

    Repair instructions 7.27 Dismantling the saw head (PT5S) Dismantle the saw head from the telescopic tube. Loosen the screw (C). Unscrew the locating screw (D) as much as required in order to twist the saw head and detach it from the telescopic tube. Remove the nut (A) and lift off the cover (B), and chain and bar.
  • Page 66 Repair instructions Remove the hose from the connection at the bar mounting using a screwdriver. Begin at the front end. Remove the pump unit from the drive axle. Remove the screw (H) completely. Press the pump axle out through the saw housing. Remove the large circlip holding the ball bearing for the pinion using a couple of pliers.
  • Page 67: Saw Head, Assembling (Pt5S)

    Repair instructions 7.28 Assembling the saw head (PT5S) Clean and inspect all components. Replace any worn or defective components. Clean the tank venting filter (A) using compressed air. Clean the oil filter (B) and rinse the inside of the oil tank using thinner if required.
  • Page 68 Repair instructions Put the oil tank and the saw housing together. Do not forget the oil filter (A). Make sure it is clean and not damaged. Make sure the tank venting filter (B) is clean. Tighten the three screws. Assembly the plastic cover and tighten the screw. Assembly the washer, spur and the spring washers.
  • Page 69: Telescopic Tube, Dismantling (Pt5S)

    Repair instructions 7.29 Dismantling the telescopic tube (PT5S) Dismantling Remove the saw head from the telescopic tube as described above. Disconnect the cables (B) and the throttle wire from carburetor. Remove cover if needed. Loosen screws (A) one on the top cover and two screws on the side,see figure.
  • Page 70: Telescopic Tube, Assembling (Pt5S)

    Repair instructions Loosen the screw holding the throttle control cover (I). Loosen the three screws (J) holding the clamping sleeve. Slide the throttle control cover and the clamping sleeve off the telescopic tube. Separate the clam- ping sleeve with a screwdriver if required. Remove the screw (K) and pull out the pipe (L) together with the rubber sleeve (M) from the telescopic tube.
  • Page 71 Repair instructions Connect the 3 springs with the bearing cages. Make sure that the bearing cages following the track inside the shaft. On the top of the bearing cages there is a protruding part that must follow the track inside the tube. Make sure they are turned in the right direction so that the axle control in the ball bearing protrudes into the telescopic tube.
  • Page 72: Assembly Saw Head, Shaft And Engine(Pt5S)

    Assembly drive shaft into tube Apply some grease on the drive shafts, mounted from engine side and from saw head side. Mount drive shaft from engine side and from saw head side. Assembly saw head Put the saw head on the shaft and tighten the nuts (D, C).
  • Page 73: Shaft, Dismantling (P4S And P5S)

    7.32 Dismantling the shaft (P4S, P5S) Loosen the screw (A) and remove the cover. Detatch the cables (B). Loosen the screws (C) and remove screw (E). Pull out the shaft (D) from the engine. Detatch the shaft from the saw head as described in chapter 7.33.
  • Page 74: Saw Head, Dismantling (P4S And P5S)

    7.33 Dismantling the saw head (P4S and P5S) Dismantle the saw head from the tube and remove the chain. Loosen the screw (C). Unscrew the screw (D) as much as required in order to twist the saw head and detach it from the tube.
  • Page 75 Loosen the screws (A) and remove the oil tank coverage. Remove the sealing and the O-ring. Remove the oil tank cap (B). Remove the oil hose and related parts (C). Remove the adjuster and spring (D). Remove the gear wheel kits from the saw head by pulling those outwards from saw head.
  • Page 76 Remove the oil pump assembly. Note: Always use Grease with art. no: 502 22 97-01 on the wheels (B,H) and in the gear. Clean and inspect all components. Replace any worn or defective components. Grease the details with grease type 502 22 97-01 before putting the parts back together.
  • Page 77: Saw Head, Assembling (P4S And P5S)

    7.34 Assembling the saw head (P4S and P5S) Assemble the different components in the reverse order as set out for dismantling in chapter 7.33. Make sure the the filter on the oil hose is in the bottom ofthe oil tank. Assemble the chain (B) on the flywheel and attach the sealing plate (E) inside the cover.
  • Page 78: Troubleshooting

    Troubleshooting 8 Troubleshooting Contents Engine does not start ....................79 Engine stops working during operation .................80 Engine is difficult to stop ....................80 Insufficient output or unstable rotation ................81 Other engine problems ....................82 - English...
  • Page 79: Engine Does Not Start

    Troubleshooting 8 Troubleshooting 8.1 Engine does not start Remove the spark plug from the cylinder, and holding the cylinder, pull the recoil starter and check whether any sparks appear between the spark plug electrodes. Symptom/Category Cause Action There are no sparks at the spark plug 1.
  • Page 80: Engine Is Difficult To Stop

    Troubleshooting 8.2 Engine stops working during operation Symptom/Category Cause Action There are no sparks at the spark plug 1. The switch has been touched, stopping Restart the engine 2. The switch is OFF Operate by setting to "RUN" or " I " 3.
  • Page 81: Insufficient Output Or Unstable Rotation

    Troubleshooting 8.4 Insufficient output or unstable rotation Symptom/Category Cause Action 1. Air has entered through the fuel pipe joint, Insert it securely etc. 2. Air has entered the fuel pipe due to a Replace crack or pin hole 3. Air has entered through the insulator pulse Insert it securely pipe insertion part, etc.
  • Page 82: Other Engine Problems

    Troubleshooting 8.5 Other Engine problems Symptom/Category Cause Action 1. The clutch spring is broken Replace the engine's clutch Even if the engine spring revolution is de- 2. The clutch is open due to rusting of the De-rust the clutch bolts, apply creased, the blade clutch bolts grease and re-assemble...
  • Page 84 2015W11...

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