Husqvarna K970 III Ring Instruction manual

Workshop manual
K970 III
English
1444 - 001 - 02.04.2020

Contents
1 Introduction
1.1 Document description............................................ 3
1.2 Target group...........................................................3
1.3 Revisions................................................................3
1.4 Safety..................................................................... 3
1.5 Servicing tools........................................................3
2 Safety
2.1 Safety definitions....................................................4
2.2 General safety instructions.....................................4
2.3 Symbols on the product......................................... 4
3 Servicing data
3.1 Symbols in the diagrams........................................5
3.2 Tightening torques ................................................ 6
4 Servicing tools
4.1 Servicing tools overview.......................................10
4.2 Servicing tools overview.......................................11
4.3 Servicing tools overview.......................................12
5 Product overview for repair and servicing
5.1 Product overview .................................................13
5.2 Basic modules of the product...............................14
6 Repair and servicing
6.1 Starter.................................................................. 22
6.2 Ignition system..................................................... 26
6.3 Flywheel............................................................... 30
6.4 Air filter................................................................. 32
6.5 Fuel system..........................................................33
6.6 Carburetor............................................................ 37
6.7 Decompression valve...........................................42
6.8 Cylinder and piston.............................................. 43
6.9 Piston wear.......................................................... 46
6.10 To assemble the piston...................................... 47
6.11 To assemble the cylinder................................... 48
6.12 Crankcase.......................................................... 49
6.13 Clutch................................................................. 55
6.14 Cutting head.......................................................58
6.15 Wet system........................................................ 63
6.16 Throttle trigger and throttle trigger lockout......... 64
7 Troubleshooting
7.1 Engine does not start........................................... 67
7.2 Engine stops during operation - no sparks...........68
7.3 Engine stops during operation............................. 68
7.4 Weak output or change of speed......................... 69
7.5 Other engine problems.........................................69
21444 - 001 - 02.04.2020

1 Introduction
1.1 Document description
This manual gives a full description of how to do
maintenance and repair on the product. It also gives
safety instructions that the personnel must obey.
1.2 Target group
This manual is for personnel with a general knowledge
of how to do repair and do servicing. All personnel that
do repair or do servicing on the product must read and
understand the manual.
1.3 Revisions
Changes to the product can cause changes to the
maintenance work and spare parts. Separate
information is sent out for each change.
Read the manual together with all received information
about changes to maintenance and spare parts for the
product.
1.4 Safety
WARNING: All personnel that repair or do
servicing on the product must read and
understand the safety instructions in this
workshop manual.
1.5 Servicing tools
The manual gives information about necessary servicing
tools. Always use original tools from Husqvarna.
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2 Safety
2.1 Safety definitions
Warnings, cautions and notes are used to point out
specially important parts of the manual.
WARNING: Used if there is a risk of injury or
death for the operator or bystanders if the
instructions in the manual are not obeyed.
CAUTION: Used if there is a risk of damage to
the product, other materials or the adjacent area
if the instructions in the manual are not obeyed.
Note: Used to give more information that is necessary in
a given situation.
2.2 General safety instructions
• Do not repair the product unless you have read and
understood this workshop manual.
• The service center where the product is repaired
must have safety equipment approved by local
bylaws.
• The product is examined and approved only with the
equipment given or recommended by the
manufacturer.
• Prevent health and safety risks. All personnel must
obey laws and requirements when they do the
procedures given in this manual.
• Obey the local waste regulations.
• Always make sure that all nuts and bolts are
correctly tightened.
• Use protective gloves and eye protection. Goggles
must obey the ANSI Z87.1 for US or EN166 for EU
countries.
• When using compressed air, do not point it to your
body. Air can go into the bloodstream.
• Use hearing protection when the engine is started.
• The product can make sparks and cause ignition of
flammable materials.
• Replace all damaged or missing warning symbol
decals.
• Gasoline and its fumes are poisonous.
• Gasoline can cause damage to the eyes and the
skin.
• Gasoline can cause breathing problems.
• Gasoline is flammable.
2.3 Symbols on the product
WARNING: Careless or incorrect use can
result in injury or death to the operator or
others.
Read the manual carefully and make sure
you understand the instructions before
using the product.
Always put on personal protective
equipment:
• Hearing protection
• Protective goggles or a visor
• Breathing mask.
This product in compliance with applicable
EC directives.
WARNING! Dust from cutting can cause
breathing problems. Use breathing
protection. Do not breathe exhaust fumes.
Always make sure there is good airflow.
WARNING! Sparks from the cutting blade
can cause a fire in materials such as,
gasoline, wood, fabric and dry grass.
WARNING! Kickbacks can be sudden,
fast and can cause injuries. Read and
understand the instructions in the manual
before using the product.
Make sure the cutting disc is not
damaged.
WARNING! Do not use circular saw
blades.
Note: Other symbols/decals on the product refer to
special certification requirements for some markets.
4 - Safety 1444 - 001 - 02.04.2020

3 Servicing data
3.1 Symbols in the diagrams
Tightening torque, Nm
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3.2 Tightening torques
9,0-11,0
9,0 -11,0
9,0-11,0
10,0-12,0
9,0-11,0
3,0-5,0
7,0-9,0
3,0-4,0 3,0-4,0
2,0-3,0
17,0-23,0
6 - Servicing data 1444 - 001 - 02.04.2020

14,0-16,0
5,0-7,0
11,0-13,0
16,0-18,0
10,0-18,0
5,0-7,0
5,0-7,0
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4,0-10,0
8,0-10,0
5,0-7,0
25,0-30,0
4,0-5,0
38,0-42,0
8 - Servicing data 1444 - 001 - 02.04.2020

6,0-8,0
12,0-14,0
35,0-40,0
20,0-25,0
25,0-30,0
7,0-10,0
7,0-10,0
14,0
2,0-3,0
7,0-9,0
3,0-4,0
17,0
2,0-3,0
2,0-3,0
14,0
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4 Servicing tools
4.1 Servicing tools overview
4 5 6
7 8
1 2 3
9
Po-
si-
tion
Designation Used for Order No./Source
1 Sealing plug To examine the crankcase for leaks. 503 55 22-01
2 Bearing press To assemble the primary bearing. 506 37 61-02
3 Press tool To disassemble and assemble the blade shaft bearings and axle. 575 96 20-01
4 Puller To disassemble the sealing rings of the crankcase in the crank-
case.
504 91 40-01
5 Assembly punch To assemble the sealing rings of the crankshaft in the crankcase. 502 50 82-01
6 Bearing press To disassemble and assemble the clutch drum ball bearing and
blade shaft bearing.
504 56 79-01
7 Universal puller To disassemble the support washer of the clutch on the crank-
shaft. To divide the crankcase.
504 90 90-02
8 Fuel filter hook To catch the fuel filter in the tank. 502 50 83-01
9 Special screwdriver To adjust the idle speed. 501 60 02-03
10 - Servicing tools 1444 - 001 - 02.04.2020

4.2 Servicing tools overview
4 5 6
7 8
1 2 3
9
Po-
si-
tion
Designation Used for Order No./Source
1 Grip plate To divide the crankcase. 544 06 00-02
2 Bearing puller Remove the primary bearing from the crankshaft. 531 00 48-67
3 Bearing press To disassemble the primary bearing and assemble the crankshaft. 544 10 36-02
4 Combination wrench General. 506 38 26-01
5 Key Torx T27 General. 502 71 27-03
6 Compression tester To examine the compression in the cylinder. 531 03 16-86
7 Kit for piston servic-
ing
To do servicing on the piston. 502 50 70-01
8 Piston stop To disassemble the clutch. 504 91 06-05
9 Wrist pin To disassemble and assemble the wrist pin. 505 38 17-05
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4.3 Servicing tools overview
4 5 6
7 8
1 2 3
0,3 mm
Po-
si-
tion
Designation Used for Order No./
Source
1 Test spark plug To do servicing on the ignition unit. 502 71 13-01
2 Air clearance gauge To adjust the air clearance between the ignition module and the fly-
wheel.
502 51 34-02
3 Flywheel puller To disassemble the flywheel. 502 51 49-02
4 Pressure tester To examine the crankcase for leaks. 531 03 06-23
5 Cylinder seal To do a test for crankcase leakages. 502 71 39-01
6 Tachometer To adjust the idle and maximum speed. 502 71 14-01
7 Pressure tester To examine the carburetor, fuel lines and check valve. 501 56 27-01
8 Cylinder seal To do a test for crankcase leakages. 506 34 45-01
12 - Servicing tools 1444 - 001 - 02.04.2020

5 Product overview for repair and servicing
5.1 Product overview
6
5
4
32
1
78
9
10
11
12
13
14
15
16
17
18
21
22
23
19
20
1. Throttle control
2. Air purge bulb
3. Cylinder cover
4. Starter
5. Starter rope handle
6. Cutting blade
7. Blade guard
8. Handle for blade guard
9. Water valve
10. Front handle
11. Choke lever
12. Air filter cover
13. Decompression valve
14. Front belt guard
15. Lock screws for belt adjustment
16. Rear belt guard
17. Belt adjustment screw
18. Fuel tank
19. Water connector
20. Sight glass for fuel
21. Rear handle
22. Throttle trigger lockout
23. Stop switch
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servicing - 13

5.2 Basic modules of the product
This chapter shows how to disassemble the product into
basic modules.
5.2.1 To remove the starter
1. Remove the 4 screws on the guard.
2. Remove the starter.
14 - Product overview for repair
and servicing
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5.2.2 To remove the cutting head
1. Loosen the hose clip with a screwdriver.
2. Loosen the 3 nuts on the cutting head. Loosen the
belt tension with the adjuster screw.
3. Loosen the nuts and remove the front belt guard.
4. Remove the belt from the pulley and remove the
cutting head.
5. Remove the 2 screws on the rear belt guard.
Remove the rear belt guard.
5.2.3 To remove the air filter
CAUTION: Be careful when the air filter is
removed. Dust particles must not fall down in
1444 - 001 - 02.04.2020 Product overview for repair and
servicing - 15

the carburetor inlet. Removal of waste is best
done with a vacuum cleaner.
1. Remove the 4 screws and remove the air filter
cover.
2. Clean around the area with a vacuum cleaner.
3. Loosen the center screw. Remove the air filter.
CAUTION: Make sure that dust does not fall
into the carburetor inlet.
5.2.4 To remove the cylinder cover
1. Remove the air filter. Refer to
To remove the air filter
on page 15 .
2. Remove the 2 screws and the cylinder cover.
5.2.5 To remove the carburetor
1. Remove the cylinder cover. Refer to To remove the
cylinder cover on page 16 .
2. Remove the choke handle.
16 - Product overview for repair
and servicing
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3. Remove the fuel hoses
4. Remove the 2 screws for the inlet hose and
carburetor.
5. Remove screw for the inlet hose.
6. Loosen the carburetor.
7. Remove the throttle cable.
8. Remove the guide for the carburetor settings.
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servicing - 17

5.2.6 To remove the air duct
1. Remove the starter. Refer to
To remove the starter
on page 14 .
2. Remove the cable lug for the stop switch cable.
3. Remove the ignition cable from the spark plug.
4. Remove the air duct.
5.2.7 To remove the muffler
1. Remove the cutting head. Refer to To remove the
cutting head on page 15 .
2. Remove the 3 screws that hold the muffler.
3. Remove the muffler.
18 - Product overview for repair
and servicing
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5.2.8 To remove and install the inlet manifold
1. Remove the carburetor. Refer to
To remove the
carburetor on page 16 .
2. Remove the screw that hold the muffler to the
crankcase.
3. Loosen the 4 screws for the cylinder.
4. Remove the screw for the vibration damping unit.
5. Remove the 2 screws for the inlet manifold.
6. Loosen the clamp.
7. Lift the cylinder approximately 1 cm.
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servicing - 19

8. Remove the inlet manifold.
9. Install in the inlet manifold in the opposite sequence.
Note: Make sure that the clamp is put fully together.
5.2.9 To remove the inlet nozzle
1. Remove the screw for the inlet nozzle.
2. Remove the the inlet nozzle.
3. Install in opposite sequence.
5.2.10 To remove the vibration damping units
1. Remove the air filter and the cylinder cover. Refer to
To remove the air filter on page 15 .
2. Remove the starter. Refer to To remove the starter
on page 14 .
3. Loosen the cable lug on the ignition module and on
the stop button. Remove the air line. Refer to To
remove the air duct on page 18 .
4. Disconnect the water hose from the valve. Refer to
To remove the cutting head on page 15 .
5. Remove the fuel hose. Refer to To remove the
carburetor on page 16 .
6. Remove the throttle wire from the carburetor. Refer
to To remove the carburetor on page 16 .
7. Remove the choke. Refer to To remove the
carburetor on page 16 .
20 - Product overview for repair
and servicing
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