Husqvarna 525P4S Instruction manual

Workshop Manual
English
525P4S 525P5S 525PT5S

English - 3
Workshop Manual
Contents
Index ..................................................................... 4
Introduction and safety instructions ...................... 6
Technical data........................................................ 10
Engine special tools .............................................. 12
Service data .......................................................... 15
Safety equipment .................................................. 24
Repair instructions................................................. 28
Troubleshooting ..................................................... 78
Contents
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.

4- English
Index
A
Air filter, dismantling and assembling ................. 36
C
Carburetor .......................................................... 37
Carburetor, dismantling ...................................... 39
Carburetor, assembling ...................................... 42
Carburetor, settings ............................................ 44
Centrifugal clutch, dismantling............................ 46
Centrifugal clutch, assembling............................ 48
Clutch drum, replacing........................................ 62
Clutch drum, dismantling and assmebling.......... 62
Crankshaft, dismantling ...................................... 59
Crankcase, dismantling ...................................... 59
Crankshaft, assembling ...................................... 61
Crankcase, assembling ...................................... 61
Cylinder and piston, dismantling ................... 49
Cleaning and inspection ................................ 51
Analysis and actions...................................... 51
Cylinder and piston, assembling......................... 58
F
Flywheel, dismantling ......................................... 46
Flywheel, assembling ......................................... 48
Fuel system ........................................................ 36
Fuel filter............................................................. 37
Fuel pump, air purge .......................................... 37
I
Introduction and safety instructions .................... 7
Ignition module, adjusting................................... 35
Ignition module, dismantling............................... 46
Ignition module, assembling ............................... 48
Ignition spark, checking...................................... 32
M
Muffler, dismantling............................................. 25
Muffler, Assbling ................................................. 25
P
Piston, dismantling ............................................. 49
Piston, assembling ............................................. 58
S
Saw head, dismantling (PT5S)........................... 65
Saw head, assembling (PT5S) ........................... 67
Saw head, dismantling (P4S and P5S) .............. 74
Saw head, assembling (P4S and P5S)...............77
Service data ....................................................... 15
Shaft, dismantling (P4S and P5S)...................... 73
Shaft, assembling (P4S and P5S)...................... 77
Special tools ....................................................... 12
Starter recoil pulley, dismantling......................... 29
Starter recoil pulley, assembling......................... 29
Start pawls, replacing ......................................... 31
Stop switch, dismantling ..................................... 25
Stop switch, assembling ..................................... 25
Stop switch, resistance test ............................... 26
Symbols in the Workshop Manual ...................... 9
Symbols on the machine .................................... 9
T
Tank Venting ....................................................... 36
Technical data..................................................... 10
Telescopic tube, dismantling (PT5S) .................. 69
Telescopic tube, assembling (PT5S) .................. 70
Throttle, dismantling ........................................... 26
Throttle, assembling ........................................... 27
Troubleshooting .................................................. 78
Engine does not start .................................... 79
Engine is difficult to stop................................ 80
Engine stops working during operation ......... 80
Insufficient output or unstable rotation...........81
Other Engine problems..................................82

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Index

6- English
Introduction and safety instructions
2 Introduction and safety instructions
Contents
2.1 General ...........................................................................................................................7
2.2 Safety .............................................................................................................................7
2.3 Target group ....................................................................................................................7
2.4 Modifications....................................................................................................................7
2.5 Tools ...............................................................................................................................7
2.6 Structure .........................................................................................................................7
2.7 Numbering ......................................................................................................................7
2.8 General instructions ........................................................................................................8
2.9 Special instructions ........................................................................................................8
2.10 Symbols on the machine ................................................................................................9
2.11 Symbols in the Workshop Manual ..................................................................................9

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2 Introduction and safety instructions
Introduction and safety instructions
2.1 General
This Workshop Manual describes in detail how
to be troubleshoot, repair and test the machine.
A description of different safety steps that must be
taken during repair work is also given.
2.2 Safety
Note: The section dealing with safety must be read
and understood by all those carrying out repair
work or service on the trimmer/brushcutter.
Warning symbols can be found in this Workshop
Manual and on the machine. See “Symbols on the
machine” and “Symbols in the Workshop Manual”.
A new warning symbol decal must be applied
as soon as possible if a warning symbol on the
product has been damaged or is missing so that
the greatest level of safety can be maintained when
using the machine.
2.3 Target group
This Workshop Manual is written for personnel who
are assumed to have general knowledge of repair-
ing and servicing the machine.
The Workshop Manual must be read and under-
stood by personnel who will carry out repair work
and service on the machine. The Manual is also
suitable for use when training new employees.
2.4 Modifications
Any modifications to the machine will be gradually
introduced into ongoing production. As these
modifications affect service and/or spare parts,
specific service information will be sent out on
each occasion. This means that in time this
Workshop Manual will become out of date. In order
to prevent this, the Manual should be read together
with all service information concerning the machine
in question.
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
2.6 Structure
This Workshop Manual can be used in two different
ways:
• Repair of a specific system on the machine.
• Dismantling and assembly of the entire machine.
Repair of a specific system
When a particular system on the machine is to be
repaired, proceed as follows:
1. Look up the page for the system in question.
2. Carry out the following steps:
Dismantling
Cleaning and inspection
Assembly
2.7 Numbering
Position references to components inside the
figures are designated A, B, etc.
The figures are numbered 1, 2 etc.
The position references and figure numbers restart
in each new section.

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2.8 General Instructions
The workshop where the machine is to be repaired
must be equipped with safety equipment in accord-
ance with local regulations.
No one may repair the machine unless they have
read and understood the content of this Workshop
Manual.
This workshop manual contains the following
warning boxes in relevant places.
2.9 Special Instructions
The fuel used in the machine has the following
hazardous properties:
• The fluid and its vapour are poisonous.
• Can cause eye and skin irritation.
• Can cause breathing problems.
• Is highly inflammable.
• Running an engine in a confined or badly ventila-
ted area can result in death due to asphyxiation
or carbon monoxide poisoning.
• Use protective gloves and eye protection, gogg-
les must comply with the ANSI Z87.1 for US or
EN166 for EU contries.
When using compressed air, do not direct the jet
towards your body. Air can penetrate into the blood
stream, which can endanger life.
Wear protective earplugs or earmuffs when test
running.
After test running, do not touch the muffler until
it has cooled down. Risk of burns. Use protective
gloves when working with the muffler.
Exercise care to ensure the starter spring does not
fly out and cause personal injury. Wear protective
glasses. If the spring tension is activated on the
starter pulley when it is to be taken up, the spring
can fly out and cause personal injury.
Keep in mind the fire risk. The machine may emit
sparks, which cause ignition.
WARNING!
The warning box warns of the risk
of personal injury if the instruc-
tions are not followed.
NOTE!
This box warns of material damage if the
instructions are not followed.
Introduction and safety instructions

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Introduction and safety instructions
2.10 Symbols on the machine
The symbols below are embedded on the machine
Choke control
Refuelling
Stop switch
Air purge
2.11 Symbols in the Workshop Manual
This symbol warns of personal injury
when the instructions are not followed.
Use protective gloves.
Use protective goggles.

10 - English
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
525PT5S: 25,4/ 1,55 34 / 1.34 28 / 1,10 1,0 / 8500
Electrode gap Ignition system Air gap Carburetor type
mm/inch mm/inch
525P4S: 0,65/0.025 IKEDA UK-08934-505 0,3/0.012 Walbro WTEA-8C
525P5S: 0,65/0,026 IKEDA UK-08934-505 0,3/0,012 Walbro WTEA-8C
525PT5S: 0,65/0,026 IKEDA UK-08934-505 0,3/0,012 Walbro WTEA-8C

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3 Technical data
Technical data
Engage speed Spark plug Volume fuel tank
rpm 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
525P4S: 4,4/9,7
525P5S: 4,6/10,1
525PT5S: 4,6/10,1

12 - English
Engine special tools
4 Engine special tools
Contents
4.1 Special tools ...................................................................................................................13

English - 13
Engine special tools
4.1 Special tools
4
2
Removal bolt
M6
5
1
7
8
For shaft (open)
12
910
3
6

14 - English
Engine special tools
11
13
14
Pos Description Used for Order No.
1 Torx wrench General disassembly / assembly tasks 578 28 90-01
2 Air gap tool (t 0.3mm) Adjust the air gap when installing the
ignition module
514 22 10-01
3 Stopper (14 mm use) Fix piston in place when installing /
removing clutch, rotor and starter pulley.
514 24 39-01
4 Puller assembly Removing the rotor (removal bolt M6) 510 13 89-01
5 Rod assembly Installing / removing the piston pin 513 18 12-01
6 Puller Installing / removing the recoil pulley 581 96 55-01
7 Plier Remove Clutch drum clip 515 41 95-01
8 Rod Remove clutch drum 581 44 10-01
9 Guide Installing clutch drum clip 581 44 11-01
10 Guide pusher Installing clutch drum clip 515 41 98-01
11 Hook for fuel filter Withdrawing the fuel filter 502 50 83-01
12 Adjustment screwdri-
ver
Adjustment of the carburetor 530 03 55-60
13 Assembly kit, piston Assembling the piston 502 50 70-01
14 Revolution counter Engine speed meter 502 71 14-01
Spark plug Testing spark plug 502 71 14-01
Pliers Ignition cable 502 50 06-01
Pressure test tool Pressure test in fuel system 531 03 06-23

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Service data
5 Service data
13
4,0
4,0
4,0
1,5
1,5
5,0
5,0
8,0
8,0
8,0
3,0
4,0
4,0
4,0
6,0
6,0 6,0
Lubricate with two-stroke oil.
Lubricate with Grease
Apply thread lock: Three bond or loctite
Tighten torque in Nm
Note!
Some of the screws are captive screws
and will remian into the cover.

16 - English
Service data
4,0
4,0
18
7,0
10
1,0
7,0
4,0
6,0

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Service data
16
3,0
8,0
7,0
7,0
7,0 8,0
8,0
15,0
8,0
8,0
8,0
8,0

18 - English
Service data
525PT5S
8-10
6-8 3-5
3-5 *3
3-5
8-10
3-4
3-4

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Service data
525PT5S 2-3
3-4
3-4 *3
5-6
5-6
1-2

20 - English
Service data
525P5S, 525P4S
4±1
10±2
3-4
6-8
8-10
3-4