Workshop manual
510 16 77-26
Workshop manual
Jonsered CS 2240 and CS 2240S
Contents
Contents
Index ....................................................................... 4
Introduction and safety instructions ................... 6
Technical data ...................................................... 10
Service tools ........................................................ 12
Service data .........................................................14
Safety equipment ................................................. 16
Repair instructions .............................................. 24
Carburettor ........................................................... 33
Troubleshooting................................................... 53
Jonsered has a policy of continuous product development and therefore reserves the right to modify the
design and appearance of products without prior notice.
English – 3
Index
Index
B
Bar bolt 52
Replacing the bar bolt 52
C
Carburettor 33
Assemble on the saw 40
Assembly 38
Carburettor adjustment 41
Cleaning and inspection 37
Design 33
Dismantling 35
Function 34
Pressure testing the carburettor 39
Centrifugal clutch 30
Centrifugal clutch - retting 31
Centrifugal clutch - removal 30
Inspection and cleaning 30
Chain brake 17
Chaine brake - reassembly 18
Cleaning and inspection 17
Dismantling the chaine brake 17
Chain catcher 20
Chain catcher - replacement 20
Crankcase and crankshaft 50
Crankshaft bearings - replacement 50
Crankshaft complete - dismantling 50
Crankshaft complete - reassembly 51
F
Fuel system 44
Replacing the fuel lter 44
Replacing the fuel hose/return hose 44
Replacing the air-purge 44
Venting the fuel tank 42
I
Ignition module and flywheel 28
Cleaning and inspection 28
Ignition module - testing 27
Ignition module and ywheel - retting 29
Ignition module and ywheel - removal 28
Intake system 32
Air intake system removal 32
Assembling the intake system 32, 48
Cleaning and inspection 32
Introduction and safety instructions 7
Changes 7
General 7
General Instructions 8
Numbering 7
Safety 7
Special Instructions 8
Symbols in the Workshop Manual 9
Symbols on the saw 9
Structure 7
Target group 7
Tools 7
O
Oil pump and screen 31
Assembling the oil pump and screen 32
Cleaning and inspection 31
Dismantling the oil pump and screen 31
P
Piston and cylinder 45
Cleaning and inspection 45
Cylinder - pressure testing 49
Faults and causes 47
Piston and cylinder - retting 47
Piston and cylinder - removal 45
S
Service data 14
Special tools 12
Silencer 19
Cleaning and inspection 19
Silencer - retting 19
Silencer - removal 19
Starter 25, 26
Changing a broken or worn starter cord 26
Cleaning and inspection 25, 26
Replacing a worn recoil spring 27
Starter assembly - retting 27
Starter assembly - removal 25
Tensioning the recoil spring 26
Start/Stop switch 20
Assembling the start/stop control 21
Cleaning and inspection 20
Dismantling the start/stop control 20
Stopping function 21
Stop switch - resistance measurement 21
T
Tank unit 42
Assembly 43
Dismantling 42
Technical Data 10
Threads 51
Repairing damaged threads 51
Throttle lock, throttle trigger
and return spring 22
Cleaning and inspection 23
Throttle lock, throttle trigger and
return spring - retting 23
Throttle lock, throttle trigger and
return spring - removal 22
4 – English
Trouble shooting 54
Trouble-shooting methods 55
V
Vibration damping system 43
Assembly 43
Cleaning and inspection 43
Dismantling 43
Index
English – 5
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 Changes ..........................................................................................................................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 saw .......................................................................................................9
2.11 Symbols in the Workshop Manual ..................................................................................9
6 – English
Introduction and safety instructions
2 Introduction and safety instructions
2.1 General
This Workshop Manual describes in detail how the
chain saw is to be fault traced, repaired and tested.
A description of different safety measures that
should 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 chain saw.
Warning symbols can be found in this Workshop
Manual and on the chain saw. See “Symbols on
the saw” and “Symbols in the Workshop Manual”. A
new decal must be applied as soon as possible if a
warning symbol on the chain saw has been damaged or is missing so that the greatest possible
safety can be obtained when using the chain saw.
2.3 Target group
This Workshop Manual is written for personnel with
general knowledge about the repair and service of
chain saws.
2.6 Structure
This Workshop Manual can be used in two different ways:
• For the repair of a particular system on the
chain saw.
•
Dismantling and assembly of the entire chain
saw.
Repair of a specific system
When a particular system on the chain saw is to be
repaired, proceed as follows:
1. Look up the page for the system in question.
2. Carry out the sections: Dismantling
Cleaning and inspection
Assembling
Dismantling and assembling the entire chain saw
Proceed as follows when the entire chain saw is to
be dismantled and assembled:
The Workshop Manual must be read and understood by personnel who will carry out repair work
and service on the chain saw. The Manual is also
suitable for use when training new employees.
2.4 Changes
Modications will be successively introduced on
the chain saw during production. When these
modications affect the service and/or spare parts,
separate 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 chain
saw in question.
2.5 Tools
Special tools are required for some stages. All
service tools are listed in the Workshop Manual.
Usage is evident from respective sections.
Always use Husqvarna’s original:
• Spare parts
• Service tools
• Accessories
1. Look up the chapter “Repair instructions”,
which deals with the Starter and carry out the
instructions set out under Dismantling.
2. Work forward in the Manual and carry out Dis-
mantling in the order set out in the sections.
3. Go back to the Starter and carry out the instructions under Cleaning and Inspection.
4. Work forward in the Manual and carry out
Cleaning and Inspection in the order set out
in the sections.
5. Order or take out all requisite spare parts from
the stores.
6. Look up the chapter “Repair instructions” which
deals with the Crankcase and carry out the
instructions set out under Assembling.
7. Work back in the Manual and carry out As-
sembling in the order set out in the sections.
Some sections include a Description of the actual
unit in order to increase the basic understanding.
2.7 Numbering
Position references to components inside the gures are designated A, B, etc.
The gures are numbered 1, 2 etc.
The position references and gure numbers restart
in each new section.
English – 7
Introduction and safety instructions
2.8 General instructions
The workshop where chain saw repairs are to be
done must be equipped with safety equipment as
set out in local provisions.
No one may repair the chain saw unless they have
read and understood the content of this Workshop
Manual.
In this workshop manual the following boxes indicate where caution should be taken.
WARNING!
The warning text warns of the risk
of personal injury if the instructions are not followed.
NOTE!
The warning text warns of the risk of ma-
terial damage if the instructions are not
followed.
2.9 Special instructions
The fuel that is used in a chainsaw poses the following hazards:
• The fuel and its fumes are toxic.
• May cause irritation to skin or eyes.
• May cause breathing difculties.
• Highly ammable.
When using compressed air the air jet should
never be pointed at the body. Air can be forced into
the bloodstream and cause fatal injury.
Wear ear protection when testing saws.
After testing a saw do not touch the silencer until
it has cooled down. The silencer gets very hot and
you may burn yourself. Wear protective gloves
when working on the silencer.
The guide bar, chain and clutch cover (chain brake)
must be tted before the saw is started. If not, the
clutch may come loose and cause injury.
Poor chain lubrication can result in failure of the
chain, which could cause serious or fatal injury.
Take care to ensure that the spring inside the
starter assembly does not y out and cause injury.
Wear eye protection. If the spring is under
compression when the pulley is removed it could
y out and cause injury.
Before removing the tensioning spring from the
chain brake, ensure that the brake is in the on
position, otherwise the spring may y out and
cause injury.
After completing the repair the chain brake must be
tested, see “Chain brake – reassembly \ Operating
test”.
Always consider the re risk. A chainsaw can
produce sparks that could start a re.
Inspect the chain catcher and replace it if it is
damaged.
8 – English
Introduction and safety instructions
2.10 Symbols on the saw
The symbols below are embedded on the chain
saw.
Choke Lever
Refuelling
Stop button
2.11 Symbols in the Workshop Manual
This symbol warns of personal injury
when the instructions are not followed
Filling with chain oil
Air purge
Chain brake, activated (right)
Chain brake, not activated (left)
English – 9
Technical data
3 Technical data
Displacement Cylinder bore Stroke Max power/speed
cm3/cubic inches Ø mm/Ø inches mm/inches kW/hp/rpm
CS 2240/S: 40,9 / 2,49 41 / 1,51 31 / 1,22 1,8 / 2,4 / 9 000
Spark plug gap Ignition system Air gap Carburettor type
mm/inches mm/inches
CS 2240/S: 0,5 / 0,02 Walbro MBU-16 0,3 / 0,012 Zama EL41AC1T
Effective cutting length Chain speed at Chain pitch Drive link
cm/inches max power – revs mm/inches mm/inches
m/s - r/min
CS 2240/S: 33-46 / 13-18 17,3 / 9 000 8,25 / 0,325 1,3 / 0,050 - 1,5 / 0,058
10 – English
GAS
OIL
Technical data
rpm
Idling speed Engagement speed Spark plug
rpm rpm
CS 2240/S: 2 900 3 800 NGK BPMR 7A
Champion RCJ 7Y
Fuel tank capacity Oil pump capacity at Oil tank capacity Automatic oil pump
Litres/US pints 8,500 rpm, Litres/US pints
ml/min
CS 2240/S: 0,37 / 0,78 9 0,25 / 0,53 Yes
Weight without Weight with
bar and chain bar and chain
kg / lbs kg / lbs
CS 2240/S: 4,4 / 9,7 5,7 / 12,6
English – 11
Special tools
4 Special tools
M5
1
4
5
M5
M6
2
6
3
7
8
10
9
11
12 – English
Special tools
12 13a
15
16b
16a
13b
16c
14
17
18
Item Description Used for Order no.
1 Clutch tool Centrifugal clutch 502 54 16-03
2 Piston stop Locking the crankshaft 504 91 06-05
3 Fuel lter hook Withdrawing the fuel lter 502 50 83-01
4 Allen key, 4mm For M5 bolts 502 50 87-01
5 Allen key, 4mm For M5 bolts 502 50 18-01
5 Allen key, 5mm For M6 bolts 502 50 64-01
6 Pressure tester Pressure testing cylinder 503 84 40-02
7 Feeler gauge Adjusting ignition module 502 51 34-02
8 Assembly xture Assembling chain saw 502 51 02-01
9 Pressure gauge Pressurisation during testing 531 03 06-23
10 Test spark plug Checking the ignition module 501 97 64-01
11 Rev counter Adjusting carburettor 502 71 14-01
12 Assembly pliers Fitting spark plug guard 502 50 06-01
13a Cover plate, exhaust Sealing the exhaust port 502 54 11-02
13b Cover plates, inlet Sealing the intake manifold 504 63 93-01
14 Assembly tool Assembling spring, chain brake 502 50 67-01
15 Puller Pulling bearing of crankshaft 504 90 90-01
16a Sleeve Fitting crankshaft 502 50 30-22
16b Shaft extension Flywheel side 502 50 30-22
16c Shaft extension Cluch side 502 50 30-22
17 Punch Dismantling the ywheel 502 51 94-01
18 Adjustment screwdriver Adjustment of the carburettor 530 03 55-60
English – 13
Service data
5 Service data
14 – English
Service data
English – 15
Safety equipment
6 Safety equipment
Contents
6.1 Dismantling the chain brake ...........................................................................................17
6.2 Chain brake - reassembly ...............................................................................................18
6.3 Silencer - removal ...........................................................................................................19
6.4 Silencer - retting ............................................................................................................19
6.5 Chain catcher - replacement ..........................................................................................20
6.6 Dismantling the start/stop control ...................................................................................20
6.7 Stop switch - resistance measurement ...........................................................................21
6.8 Assembling the start/stop control ....................................................................................21
6.9 Throttle lock, throttle trigger and return spring - removal ................................................22
6.10 Throttle lock, throttle trigger and return spring - retting .................................................23
16 – English
6 Safety equipment
6.1 Dismantling the chain brake
1
Release the brake by moving the front hand guard
backward. Loosen the bar nut and remove the
clutch cover, chain and bar (see gure 1).
2
Carefully tighten the clutch housing in a vice.
Release the brake by using the saw's front hand
guard (A) as a tool. Mesh with the brake and tighten anti-clockwise until the brake is activated. (see
gure 2)
Safety equipment
Fig 1
WARNING!
Exercise care to ensure the spring
does not fly out and cause personal injury. Wear protective glasses.
3
Loosen the screws and carefully remove the cover
over the brake spring. (see gure 3)
4
Hold one hand over the brake spring; press a narrow screwdriver in between the rear section of the
spring and the clutch cover. Carefully pry upward
until the spring releases and runs onto the screwdriver shaft. (see gure 4)
Fig 2
Fig 3
Cleaning and inspection
• Carefully clean and check all parts. Parts must
be replaced if cracked or show signs of other
defects. Always use original spare parts.
• Measure the thickness of the chain brake band.
It must not be less than 0.6 mm at any point.
(see gure 5)
• Lubricate the knee joint with grease.
Fig 4
min 0,6 mm
Fig 5
English – 17
Safety equipment
6.2 Chain brake – reassembly
1
Bolt the elbow joint to the brake band (see gure 5)
and tighten to a torque of 1–1.5 Nm.
Locate the elbow joint and connected brake band
in their recesses in the clutch cover. Lubricate the
recess for the spring with grease (see gure 6).
Secure the circlip (A) (see gure 6).
2
Grip the clutch cover in a vice. Compress the
spring with special tool 502 50 67-01 and push it
down with your thumb (see gure 7).
WARNING!
Make sure the spring does not fly
out and cause injury. Wear eye
protection.
Fig 6
3
Fit the cover over the chain brake spring, tightening the screws to a torque of 1–1.5 Nm (see gure
8).
4
Tension the brake spring by using the kickback
guard from the saw as a tool. Engage it with the
brake mechanism and turn clockwise to release
the brake (see gure 9).
5
Turn the chain tensioner anticlockwise as far as it
will go.
Fig 7
Fig 8
Ret:
• guide bar
• chain
• clutch cover
NOTE!
After completing the repair the chain
brake must be tested as described below.
18 – English
Fig 9
Operating test:
The engine must not be running during the test.
Guide bar length Height
38cm/15" 50 cm/20"
• Hold the chainsaw over a rm surface. The
height of the guide bar above the surface is
given in the table above.
• Let go of the front handle and let the chainsaw
fall towards the surface.
• When the guide bar hits the surface the chain
brake must engage (see gure 10).
6.3 Silencer – removal
WARNING!
Do not touch the silencer until it
has cooled down, otherwise you
may burn yourself.
1
Remove the cylinder cover, silencer, gasket and
cooling plate.
Safety equipment
Fig 10
2
If the saw is tted with a spark arrestor mesh (A) this
must also be removed. If necessary, use the combination spanner to push down the plate edge and
remove the spark arrestor mesh (see gure 11).
Cleaning and inspection
Clean and inspect all parts carefully. If there are any
cracks or other defects replace the damaged parts
with new ones.
The spark arrestor mesh is best cleaned with a wire
brush. If the mesh is damaged it must be replaced.
If the mesh is blocked the saw will overheat and this
will cause damage to cylinder and piston.
Never use the saw with a silencer that is in poor
condition. Always use original parts.
6.4 Silencer – refitting
1
If the saw is equipped with a spark arrestor mesh
this should be tted rst. When tting the mesh,
make sure that the mesh is inserted in the right
position. If necessary, use the combination spanner
to insert the mesh.
Fig 11
2
Ret
• cooling plate
• gasket
• silencer, tighten bolts to a torque of 8–10 Nm.
• cylinder cover
3
Run the saw for at least 1 minute, then retighten the
silencer bolts to 12–14 Nm.
English – 19
Safety equipment
6.5 Chain catcher – replacement
If the chain catcher is worn it must be replaced with
a new one.
1
Release the brake by pushing the kickback guard
backwards. Undo the guide bar bolts and remove
the clutch cover, chain and guide bar.
2
Remove the chain catcher and replace it with a
new one. Check that the vibration damping spring
locates correctly against the crankcase when you
bolt the new chain catcher in position. (see gure
12)
6.6 Dismantling the start/stop control
1
Remove the cylinder cover and air lter.
2
Loosen the screw and dismantle the control (see
gure 13).
Fig 12
3
Loosen the lter holder from the rubber mountings
(B). (see gure 13)
4
Cut off the starlock washer and pull out the control
from the shaft on the lter holder.(see gure 14)
Cleaning and inspection
Clean and inspect all parts carefully. If there are
any cracks or other defects replace the damaged
parts with new ones. Always use original parts.
Fig 13
20 – English
6.7 Stop switch – resistance
measurement
Clean the mating surfaces and check the resistance as follows:
Measure the resistance by connecting a multimeter to the ignition coil. NOTE! The switch must be
in the “on” (A) position to give the correct reading
(see gure 14).
The resistance must not be higher than 0.5 Ohm
when the switch is in the on position.
Safety equipment
The stop switch is in the on position when the
button is held down (A) (see gure 14) and in the
off-position the button is neutral (B) (see gure 15).
6.8 Assembling the start/stop control
1
Fit a new control and tighten the screw.
Fig 14
Fig 15
2
Fit air lter and cylinder cover.
Fig 16
English – 21
Safety equipment
6.9 Throttle lock, throttle trigger and
return spring – removal
1
Loosen the throttle actuator rod on the carburettor,
the fuel hose and the suction hose to the fuel pump.
2
Dismantle the tank unit from the engine unit by
loosening the screws A (see gure 17)
3
Dismantle the handle insert (B) by loosening the
screw C on the handle (see gure 18).
4
Press out the throttle control pin (D) with the help
of a punch (see gure 19).
Fig 17
Fig 18
A
A
A
2xA
A
5
Loosen the throttle lock as illustrated with the help
of a screwdriver or the like. Then dismantle from
the shaft in the handle (see gure 20).
6
Dismantle the throttle control (see gure 20).
7
Now loosen the spring.
Fig 19
Fig 20
22 – English
Fig 21
Cleaning and inspection
• Clean and inspect all parts carefully. If there are
any cracks or other defects replace the damaged parts with new ones. Always use original
parts.
• Check that the spring is not broken and has not
lost its tension.
6.10 Throttle lock, throttle trigger and
return spring – refitting
1
Lubricate all pins and mating surfaces with a light
oil.
2
Fit the throttle control (B) and spring (C) (see
gure 22).
3
Hold the spring and insert the throttle lock into the
cut-out in the handle (see gure 23).
Safety equipment
4
Fit the throttle control pin (E) with the help of a
punch. (see gure 23)
5
Fit the throttle lock (D) by pressing it onto the shaft
in the handle (see gure 24).
6
Assemble the handle insert using a screw, when
the throttle control, lever, throttle cable and throttle
control lock with pin are tted correctly (see gure
25).
Fig 22
Fig 23
Fig 24
English – 23
Repair instructions
7 Repair instructions
Contents
7.1 Starter assembly - removal .............................................................................................25
7.2 Changing a broken or worn starter cord .........................................................................26
7.3 Tensioning the recoil spring ............................................................................................26
7.4 Replacing a worn recoil spring .......................................................................................27
7.5 Starter assembly - retting ..............................................................................................27
7.6 Ignition module - testing .................................................................................................27
7.7 Ignition module and ywheel - removal ..........................................................................28
7.8 Ignition module and ywheel - retting ...........................................................................29
7.9 Centrifugal clutch - removal ............................................................................................30
7.10 Centrifugal clutch - retting .............................................................................................31
7.11 Dismantling the oil pump and screen ..............................................................................31
7.12 Assembling the oil pump and screen ..............................................................................32
7.13 Air intake system - removal ............................................................................................32
7.14 Assembling the intake system ........................................................................................32
7.15 Carburettor .....................................................................................................................33
7.16 Tank unit .........................................................................................................................42
7.17 Venting the fuel tank .......................................................................................................42
7.18 Vibration damping system ..............................................................................................43
7.19 Replacing the fuel lter ...................................................................................................44
7.20 Replacing the fuel hose/return hose ...............................................................................44
7.21 Replacing the air-purge ...................................................................................................44
7.22 Piston and cylinder - removal .........................................................................................45
7.23 Piston and cylinder - retting ..........................................................................................47
7.24 Cylinder - pressure testing ..............................................................................................49
7.25 Crankshaft complete - dismantling .................................................................................50
7.26 Crankshaft bearings - replacement ................................................................................50
7.27 Crankshaft complete - reassembly .................................................................................51
7.28 Repairing damaged threads ...........................................................................................51
7.29 Replacing the bar bolt .....................................................................................................52
24 – English
7 Repair instructions
7.1 Starter assembly – removal
1
Undo the four bolts that fasten the starter assembly
to the crankcase and lift off the starter assembly.
(see gure 1)
2
Pull out about 30 cm of the cord and fasten it in the
notch in the pulley rim. Release the tension in the
return spring by letting the pulley wind backwards
slowly. (see gure 2)
Fig 1
Repair instructions
1
2
WARNING!
If the recoil spring is still under
tension when the pulley is removed it can fly out and cause
injury. Wear eye protection.
3
Remove the bolt from the centre of the pulley and
lift off the pulley. (see gure 3)
Cleaning and inspection
Clean the parts and check the following:
• The starter cord.
• That the pawls on the ywheel are undamaged, i.e. that they spring back towards the
centre and move freely.
• Lubricate the return spring with light oil.
Fig 2
Fig 3
English – 25
Repair instructions
7.2 Changing a broken or worn starter
cord
When the starter cord is worn and must be replaced,
the tension on the return spring must be released.
1
Pull the cord out about 30 cm and lift it into the notch
on the outside of the starter pulley. Release the
tension on the return spring by allowing the starter
pulley to rotate slowly backwards (see gure 2).
WARNING!
If the spring tension is activated
on the starter pulley, the spring
can fly out and cause personal
injury. Wear protective glasses.
2
Undo the bolt in the centre of the pulley and remove the pulley (see gure 3).
3
Fit a new cord through the hole in the pulley and tie
a knot to secure it. Feed the other end of the cord
through the hole in the starter housing and through
the starter handle, then tie a double knot in the
end. Wind about 3 turns of the starter cord onto the
pulley. Fit the bolt through the centre of the pulley
and tighten to a torque of 2–3 Nm.
Cleaning and inspection
• Clean and inspect all parts carefully. If there
are any cracks or other defects replace the
damaged parts with new ones. Lubricate the
return spring with a little grease.
7.3 Tensioning the recoil spring
1
Fasten the starter cord in the notch in the pulley
rim and wind the pulley about 3 turns clockwise.
Check that the pulley is free to rotate at least another half turn when the starter cord is fully extended (see gure 4).
2
Tension the cord with the handle. Remove the
thumb and released back the cord (see gure 5).
Fig 4
26 – English
Fig 5
7.4 Replacing a worn recoil spring
WARNING!
Make sure the recoil spring does
not fly out and cause injury. Wear
eye protection..
1
Remove the bolt from the centre of the pulley and
lift off the pulley and spring cassette.
2
Replace the defective spring cassette with a new
one.
3
Fit the bolt through the centre of the pulley and
tighten to a torque of 2–3 Nm. Tension the recoil
spring, see “Tensioning the recoil spring”.
Repair instructions
7.5 Starter assembly – refitting
1
Position the starter assembly on the crankcase and
tighten the bolts to a torque of 2.5–3.5 Nm.
7.6 Ignition module – testing
If there is a fault in the ignition system the ignition
module must be tested before the ignition system
is removed.
Test the ignition module as follows:
• Connect a test spark plug 502 71 13-01 to the
ignition lead and clip the test spark plug onto
the cylinder.
• Turn the engine over using the starter cord.
• If the test spark plug produces a spark the
ignition module is OK. (see gure 7)
Fig 6
Fig 7
English – 27
Repair instructions
7.7 Ignition module and flywheel
– removal
1
Remove the cylinder cover. Disconnect the HT lead,
remove the spark plug and t piston stop 502 54 15-
01. in its place. Take off the starter assembly, release
the leads from the cable guide and remove it (see
gure 8).
2
If replacing the ignition module (B), loosen the
cable lug (C) and screw (A) and unscrew it. The
ignition module can be left in place if you are simply
removing the ywheel (see gure 9).
Fig 8
3
Loosen the ywheel nut (E) using a suitable socket
and remove it (see gure 10).
When replacing the cables, they are tted on the
stop switch, as shown in gure (see gure 9).
4
Knock on the punch using a metal mallet until
the ywheel releases from the shaft. Remove the
punch and the ywheel (see gure 10).
Cleaning and inspection
• Clean all parts, especially the tapers on the
ywheel and shaft.
Fig 9
• Check that the ywheel is not cracked or damaged in any other way.
28 – English
Fig 10
7.8 Ignition module and flywheel
– refitting
1
Fit the ywheel on the crankshaft journal. Turn the
ywheel so that the key lines up with the keyway in
the shaft.
Fit the nut on the shaft and tighten to a torque of
25-30 Nm (see gure 11).
2
To ret the ignition module proceed as follows:
Turn the ywheel so that the magnets are in line with
the ignition module. Fit the ignition module with the
plastic feeler gauge (502 51 34- 02) held in position
at the same time, without tightening the bolts. Fit the
earth cable (black) (A). Set a distance of 0.3 +/- 0.1
mm, between the ignition module and magnet. The
measurement applies to the two lowest lugs on
the ignition module. Tighten the screws, tightening
torque 4.5–6 Nm. Fit the blue cable on the ignition
module (see gure 12).
Repair instructions
Fig 11
3
Then ret:
• cable guide and press the leads into position
• HT lead
• starter assembly, tighten to a torque of 2.5–3.5
Nm
• cylinder cover
When replacing the cables, they are tted on the
stop switch as shown in middle gure on the previous page.
Fig 12
English – 29
Repair instructions
7.9 Centrifugal clutch – removal
1
Remove the cylinder cover. Disengage the chain
brake by pushing the kickback guard backwards.
Undo the bar nut and remove the clutch cover, bar
and chain (see gure 13).
2
Disconnect the HT lead. Remove the spark plug
and t piston stop 502 54 15-01 (A) in its place
(see gure 14).
3
Unbolt the clutch using tool 502 54 16-03 (B) and
a suitable socket or wrench. Turn the clutch clockwise to remove it (see gure 15).
Fig 13
A
4
Secure the clutch in a vice as shown in gure. Carefully release the clutch springs (C) (see gure 16).
NOTE!
Handle the clutch springs carefully. If they
are opened up too much they could damage the saw.
Inspection and cleaning
• Clean and inspect all parts carefully. If there
are any cracks or other defects replace the
damaged parts with new ones. Always use
original parts.
• Check the thickness of the clutch shoes by
using vernier callipers to measure the diameter
of the clutch. If the diameter is less than 60
mm the clutch assembly must be replaced (see
gure 16).
Fig 14
B
Fig 15
30 – English
Fig 16
7.10 Centrifugal clutch – refitting
1
Insert the clutch springs in the shoes.
2
Screw the clutch (anti-clockwise) until it stops.
Now tighten using tool 502 54 16-03 and a suitable
socket wrench or combination spanner. Tightening
torque min. 20 Nm.
3
Remove the piston stop. Fit the spark plug, tightening
it to a torque of 20 Nm, then connect the HT lead.
Then ret:
• cylinder cover
• guide bar
• chain
• clutch cover
Repair instructions
7.11 Dismantling the oil pump and
screen
1
Empty and clean the oil tank.
Remove the cylinder cover. Release the brake by
moving the front hand guard backward. Undo the
bar nut and remove the clutch cover, bar and chain.
Loosen spark plug cap and remove the spark plug,
t the piston stop 502 54 15-01. Loosen the clutch
(clockwise) using tool 502 54 16-03 and a suitable
socket wrench or combination spanner.
2
Remove the centrifugal clutch (A). Remove the
clutch drum (B), needle bearing (C) and pump
drive wheel (D) (see gure 17).
3
Unscrew the chain guide plate (see gure 18).
4
Unbolt the oil pump from the crankcase and
remove it together with the oil pressure hose (see
gure 19).
5
The oil pump (E) is not adjustable (see gure 20).
Cleaning and inspection
• Clean and inspect all parts carefully. If there are
any cracks or other defects replace the damaged parts with new ones. Always use original
parts.
Fig 17
Fig 18
E
Fig 19
E
• Lubricate all moving parts with chain oil.
Fig 20
English – 31
Repair instructions
7.12 Assembling the oil pump and screen
1
Fit the chain guide plate with tightening torque
1–1.5 Nm.
Fit the drive gear, needle bearing, clutch drum and
the clutch (min. 20 Nm).
Fit the chain, bar and clutch cover.
WARNING!
Poor chain lubrication can result
in failure of the chain, which could
cause serious or fatal injury.
7.13 Air intake system – removal
The air intake system comprises:
• intake manifold (A)
• plastic partition wall (B)
• rubber partition wall (C)
(see gure 21)
7.14 Assembling the intake system
1
Fit the intake manifold (A) and the partition walls
(B and C) on the cylinder using tool 502 50 87-01
(see gure 21).
Cleaning and inspection
Clean and check all parts carefully. Parts must be
replaced if cracked or show signs of other defects.
Always use original spare parts.
1
Now loosen the screws using tool 502 50 87-01..
Fig 21
32 – English
7.15 Carburettor
WARNING!
The fuel used in the chainsaw has
the following hazardous properties:
1. The fluid and its fumes are
poisonous.
2. Can cause skin irritation.
3. Is highly inflammable.
Description
The drawings accompanying this description do not
correspond with the carburettor on the chainsaw.
They only show the principle for the design and
function.
Design
The carburettor is based on three sub-systems:
• The metering unit, A.
• The mixing venturi, B.
Repair instructions
• The pump unit, C.
The jets and the fuel’s control functions are located
in the metering unit (A). Here the correct quantity
of fuel is adjusted for the actual speed and power
output (see gure 22).
The mixing venturi (B) houses the choke, throttle
valve and diffuser jets. Here air is mixed with the
fuel to give a fuel/air mixture that can be ignited by
the ignition spark (see gure 23).
In the pump unit (C), fuel is pumped from the fuel
tank to the metering unit. One side of the pump diaphragm is connected to the crankcase and pulses
in time with the pressure changes in the crankcase.
The other side of the diaphragm pumps the fuel
(see gure 24).
Fig 22
Fig 23
Fig 24
English – 33
Repair instructions
Function
The carburettor operates differently in the following
modes:
• Cold start mode
• Idling mode
• Part throttle mode
• Full throttle mode
In the cold start mode (see gure) the choke valve
(H) is fully closed. This increases the vacuum in
the carburettor so that fuel is sucked more easily
from all the diffuser jets (D, E and F). The throttle
valve (I) is partly open. Extra air inlet (J) is closed
(see gure 25).
In the idling mode (see gure) the throttle valve (I
and J) is closed and the choke valve (H) is open.
Air is sucked in through an aperture in the throttle
valve and a small amount of fuel is supplied through the diffuser jet (D) (see gure 26).
Fig 25
In the part throttle mode (see gure below) the throttle valve (I) is partially open and the choke valve
(H) is open. Fuel is supplied through the diffuser
jets (D and E). The throttle valve (J) starts to open
(see gure 27).
In full throttle mode (se gure below) all valves
are open and fuel is supplied through all diffuser
jets (D, E, F and G). Extra air inlet (J) is also fully
opened (see gure 28).
Fig 26
Fig 27
34 – English
Fig 28
Dismantling the carburettor
1. Dismantle the cylinder cover and the air lter.
2. Disassemble the handle holder (see gure 29).
3. Push the throttle actuator rod out of the handle part. Unhook it from the carburettor (see
gure 30).
Repair instructions
Fig 29
4. Remove the return hose (B) and suction hose
(C). Loosen the fuel pump (D). Let the fuel
hose (G) remain in place (see gure 31).
NOTE!
Take care when lifting out the carburettor so
that the fuel hose does not become loose.
5. Loosen the screws (E) and unhook the rubber
mountings (F) (see gure 32).
Fig 30
Fig 31
Fig 32
English – 35
Repair instructions
6. Disassemble the pump cover (G) over the
measuring chamber cover (R) and carefully
remove the control diaphragm (H) with gasket
(J).
7. Unscrew the screw (K) and remove the needle
valve (L) with lever (M), shaft (N) and spring
(P).
8. Unscrew the screw (Q) above the pump unit
and carefully remove the gasket (S) and diaphragm (T).
9. Use a needle or similar device and carefully
pull up the fuel screen (U).
10. Unscrew the high (V) and low jet screws (W)
(see gure 34).
11. If necessary, dismount the throttle valve (X),
choke valve (Z) and air shutter (Y) and remove
the shafts with levers and springs (see
gure 34).
Fig 33
36 – English
Repair instructions
Cleaning and inspection
Clean all units in clean petrol.
Use compressed air to dry the petrol on the components. Direct the air through all channels in the
carburettor housing and ensure that they are not
blocked. Check the following:
1. That gaskets, pump and control diaphragms
are undamaged.
2. That there is no play on the throttle and choke
valve shafts.
3. That the needle valve (L) and its lever (M) are
not worn (see gure 33).
4. That the fuel screen (U) is whole and clean
(see gure 33).
5. That the tips of the high (V) and low jet screws
(W) are not damaged (see gure 34).
6. That the intake manifold (R2) is undamaged
(see gure 33).
7. The carburettor has an extra air shutter connected in parallel with the ordinary throttle
valve.
Fig 34
English – 37
Repair instructions
Assembly
Maintain a high level of cleanliness when assembling the carburettor. The slightest contamination
can result in running problems.
1. If the throttle and choke valves, together with
levers and springs were removed, they should
be retted. The spring is tensioned 1-2 turns.
Lubricate the shaft bearings with light oil.
2. Fit the high (V) and low (W) speed needles and
springs. Note! Do not fully tighten the screws.
This will damage the seats and needle tips.
3. Fit the fuel lter (U) by using the handle of a
small screwdriver. (see gure 33)
4. Fit pump cover (G), gasket (S) and measuring
chamber cover (R) over the pump unit (see
gure 33).
5. Fit the needle valve (L) with lever (M), shaft (N)
and spring (P) and tighten the screw (K). Fit
the expansion washer (F) (see gure 35).
6. Check using a ruler or the like that the lever
is level with the assembly plane on the cover.
The lever arm can be bent if necessary (see
gure 36).
Fig 35
7. Fit the control diaphragm (T) with gasket (S)
and measuring chamber cover (R) over the
metering unit (see gure 37).
8. Press in the screen (U). Fit the measuring
chamber cover (R) and tighten the screw (Q)
(see gure 37).
9. Put together the gasket (J) and control diaphragm (H) and press up (see gure 37).
10. Assemble all the parts and tighten the four
screws (see gure 37).
11.. Carry out a pressure test.
Fig 36
38 – English
Fig 37
Pressure testing the carburettor
Pressure testing should be carried out with the carburettor fully assembled. Testing should always be
carried out after the carburettor has been repaired,
but it can also be carried out as trouble shooting
before dismantling the carburettor.
See gure and carry out the test as follows:
1
Set the high and low jet screws two turns from
the bottom.
Repair instructions
2
Connect pressure tester to the carburettor’s fuel
intake.
3
Lower the carburettor into a beaker of water (see
gure 37).
4
Pump the pressure up to 50 kPa.
5
No leakage is permitted. If a leakage occurs refer
to the table below.
Leakage at Fault with
Diffuser jets Needle valve
Leakage in impulse tube Pump diaphragm
Ventilation hole
on metering unit. Control diaphragm
Fig 38
English – 39
Repair instructions
Assemble on the saw
1. Press the carburettor down towards the partition wall. Make sure that it gets into the correct
position.
2. Fit the lter holder by hooking the choke control into the choke lever (A).
3. Hook on the rubber mountings. Insert and
tighten the screws.
4. Insert the return hose (B) into its position in the
lter holder.
5. Press on the fuel diaphragm (D). Fit the suction hose (C) and return hose (B).
Fig 39
6. Hook in the throttle actuator rod into the carburettor. Thread the handle holder into the throttle
actuator rod (A). Push the rod forwards so that
it can be inserted into the handle part.
7. Push down the handle holder into the lter
holder (see gure 42).
8. Assemble the air lter and cylinder cover.
9. Mount the handle holder.
Fig 40
Fig 41
40 – English
Fig 42
Carburettor adjustment
Conditions during adjustment
•
The air lter should be clean and the cylinder
cover tted when adjustments are made. Adjusting the carburettor with a dirty air lter will
give a too lean fuel mixture the next time the
air lter is cleaned. This can result in serious
damage to the engine.
• Mount, for this model, approved bar and
chain combination (see Technical data in the
Operator's Manual).
CS 2240/S 16"
• The chain should not be tensioned more than
that it remains ~ 0,2 inches to the bar.
(See gure 43)
Replacement of the H-needle or complete carburettor
1. Carefully screw the new H-needle to the bottom and turn it anticlockwise ”A” turns.
Repair instructions
Fig 43
CS 2240/S A = 2
2. Start the engine. If necessary, adjust the idling
speed with the T-screw until the chain stops.
3. Adjust the H-needle to give a top speed of ”B”
rpm. Use a tachometer.
CS 2240/S B = 12500-13 000, speed limitation
Use screwdriver 530 03 55-60.
4. Let the engine run at ”B” rpm ~ 1 minute, until
warm.
Replacement of the L-needle
1. Screw the new L-needle to the bottom and
then turn it counterclockwise ”D” turns.
CS 2240/S D = 2,5
(See gure 44)
Fig 44
L
H
T
English – 41
Repair instructions
A
7.16 Tank unit
WARNING!
The fuel used in the chain saw has
the following hazardous properties:
1. The fluid and its vapour are
poisonous.
2. Can cause skin irritation.
3. Is highly inflammable.
Dismantling
1. Drain the fuel from the tank.
2. Dismantle the cylinder cover, bar and chain.
See the Operator's Manual.
3. Unhook the throttle actuator rod (G) from the
carburettor (see gure 45).
4. Dismantle the fuel hose (B) and the fuel pump
return hose (D) (see gure 45).
5. Remove the screws. (A). Loosen the handle
(see gure 46).
6. Dismantle the fuel tank.
Fig 45
NOTE!
Exercise care so that the fuel hose and
throttle cable are not damaged.
7.17 Venting the fuel tank
The two-way valve (C) has the following properties
(see gure 47):
• Controlled opening pressure in both directions,
which prevents a positive pressure or a vacuum
developing in the fuel tank and impairing engine
performance. This also prevents fuel leakage.
• Opening pressure outward 100–450 mbar.
• Opening pressure inward (vacuum) max.
70 mbar. (2 positions)
Test
Opening pressure outward:
1. Open the ller cap and let the cap remain open
during the entire test. Drain the fuel from the
tank.
2. Connect the pump, ref. no. 531 03 06-23, to
the tank valve. (C)
3. Switch the pump to vacuum mode.
4. After pumping the indicator should be between
10–45 kPa.
Opening pressure inward:
1. Open the ller cap and let the cap remain open
during the entire test. Drain the fuel from the
tank.
2. Connect the pump, ref. no. 531 03 06-23, to
the tank valve. (C)
3. Switch the pump to pressure mode.
Fig 46
Fig 47
3xA
2xE
A
4. After pumping the indicator should stop at max.
7 kPa.
42 – English
Assembly
1. If the throttle lock has been removed, this must
be assembled before the tank unit and engine
unit are assembled.
2. Lift the engine unit above the tank unit and
insert the fuel hose (in J), return hose (in H) in
the bottom of the carburettor compartment (see
gure 48).
3. Fit the handle with the screws (A). Tighten the
screws with the torque set out in the service
data (see gure 46).
4. Fit the fuel hose (B) and fuel pump return hose
(D) on the carburettor (see gure 45).
5 Mount the throttle actuator rod (see gure 45).
6 Assemble the cylinder cover, bar and chain.
See the Operator's Manual.
7.18 Vibration damping system
Repair instructions
Fig 48
Dismantling
1. Dismantle the following parts:
• Bar and chain. See the Operator's Manual.
• Cylinder cover. See the Operator's Manual.
• Tank unit and handle.
2. Dismantle the spring on the cylinder with the
help of a 5 mm allen key (see gure 49).
3. Dismantle the springs on the tank unit with the
help of a 5 mm allen key (tool 502 50 18-01)
(see gure 50).
Cleaning and inspection
Clean and inspect all parts.
Assembly
1. Assemble the springs on the cylinder with the
help of a 5 mm allen key (tool 502 50 18-01).
Note! Springs with a greater resistance are av-
ailable, but should only be used together with
a longer bar. See illustrated part list for spare
part number.
2. Assemble the following parts:
Fig 49
Fig 50
• Tank unit and handle.
• Cylinder cover. See the Operator's Manual.
• Bar and chain. See the Operator's Manual.
English – 43
Repair instructions
7.19 Replacing the fuel filter
NOTE!
Do not use knurled pliers to disconnect or
reconnect the fuel hose. This could damage the hose and lead to leakage or fracture.
1
First remove the old fuel lter from the tank unit
using special tool 502 50 83-01.
2
Pull the fuel hose (B) out of the tank unit and pull
off the lter.
3
Fit the new fuel lter (A) and feed the fuel hose
back into position.
7.20 Replacing the fuel hose/
return hose
The fuel hose is moulded and can only be removed
from outside of the fuel tank.
Use suitable pliers with a plain cutting face and
loosen the hose (B) (see gure 45) from the fuel
tank. Align the cut-out against the plastic pin when
assembling. Replace the return hose when required.
Fig 51
7.21 Replacing the air-purge
Dismantling
1. Dismantle the cylinder cover and the air lter.
2. Loosen the suction hose (C) and return hose
from the fuel pump (see gure 31).
3. Unsnap the fuel pump from the lter holder.
Assembling
1. Fit the return hose on the fuel pump.
2. Snap the purge into the lter holder (see gure
51).
4. Assemble the air lter and cylinder cover.
Fig 52
44 – English
7.22 Piston and cylinder – removal
1
Remove:
• cylinder cover
• carburettor (see “Carburettor – removal”)
• silencer
• spark plug
• fuel unit
2
Undo the four cylinder bolts from the underside and
lift the cylinder off carefully (see gure 52).
Repair instructions
Fig 53
3
Cover the opening in the crankcase (see gure 54).
4
Remove the circlips from the ends of the gudgeon
pin and press it out. Then lift off the piston (see
gure 53 and 54).
5
Remove the little end bearing (see gure 54).
If replacing the cylinder:
Remove the intake manifold, see “Air intake system – removal”.
Fig 54
Fig 55
Cleaning and inspection
Clean all the components, scraping off all traces of
old gasket and carbon from the following places:
• Piston crown
• Top of the cylinder bore
• Cylinder exhaust port
• Decompression valve channel
• Cylinder base and/or crankcase
(see gure 56)
Fig 56
English – 45
Repair instructions
Check the following:
• The surface coating of the cylinder is not worn
through, especially in the upper part of the
cylinder.
• The cylinder is free from score marks and
areas of wear.
• The piston is free from score marks. Small
scratches can be polished out with ne emery
paper.
• The piston ring is freely moving in its groove.
(see gure 57)
• Measure piston ring wear. This should not
exceed 1 mm (see gure 58). Use the piston to
push the piston ring for correct alignment.
• The needle roller bearing is undamaged.
• The intake manifold is undamaged.
• That the air hoses and impulse hose are unda-
maged.
• Pressure test the decompression valve.
Fig 57
Fig 58
46 – English
A
B
Faults and causes
Score marks on the piston (A)
1. Incorrect carburettor setting. Too high overspeed.
2. Too low octane fuel.
3. Too low or incorrect oil in the fuel.
Carbon build-up (B)
1. Incorrect carburettor setting. Too low overspeed.
2. Too much or incorrect oil in the fuel.
Piston ring breakage
1. Excessive engine speed.
2. Piston ring worn out.
3. Oversized piston ring groove.
(See gure 59)
7.23 Piston and cylinder – refitting
Repair instructions
Fig 59
1
Lubricate the little end bearing with two-stroke oil
and insert it in the connecting rod (see gure 60).
2
Fit the piston with the arrow pointing towards the
exhaust port. Push the gudgeon pin in and t the
circlips. NOTE! Use new wire fuses (see gure 60).
3
Fit the intake manifold on the cylinder, with insulating plate (4 screws).
4
Lubricate the piston ring and piston with two-stroke
oil.
5
Fit new cylinder base gaskets. Lower the cylinder
over the piston carefully.
6
Fit the cylinder bolts, tightening them in diagonal
pairs to a torque of 13–15 Nm.
Fig 60
NOTE!
It is very important that there are no leaks
in the inlet system, otherwise the engine
may seize.
Fig 61
English – 47
Repair instructions
Inlet manifold
The intake system has two intakes.
1. The lower intake leads the fuel and air mixture
from the carburettor to the cylinder.
2. The upper intake leads air to the cylinder.
Assembling the intake system
1
Mount the intake manifold (A) and the partition
walls (B and C) on the cylinder using tools 502 50
87-01 (see gure 62).
Fig 62
48 – English
7.24 Cylinder – pressure testing
1
Remove:
• cylinder cover
• carburettor
• spark plug
2
Mount cover plate 502 54 48-02 (see gure 63).
Repair instructions
3
Loosen the screws on the mufer and press the
rubber sheet 502 54 11-02 between the mufer and
cylinder. Tighten the top two mufer screws (see
gure 64).
4
Fit the pressure testing spark plug 503 84 40-02
and connect the pressure testing tool 531 03 06-23
(see gure 64).
5
Pump the pressure up to 80 kPa (0.8 bar). Wait
30 seconds. The pressure should not be less than
60 kPa (0.6 bar). Remove the cover plates from
the silencer and carburettor, tighten the bolts to the
specied torque. Remove the pressure test nipple
503 84 40-02 and ret the spark plug.
WARNING!
After pressure testing the cylinder,
check that the inlet manifold is
seated correctly, otherwise the saw
may be damaged.
Fig 63
Fig 64
Fig 65
English – 49
Repair instructions
7.25 Crankshaft complete - dismantling
1
Remove the following:
• chain and bar
• clutch cover
• cylinder cover
• starter assembly*
• centrifugal clutch*
• carburettor*
• silencer*
• handle system
• hand guard
• piston and cylinder*
* See special instructions.
2
Lift the crankshaft completely out of the crankcase
(see gure 66).
Fig 66
7.26 Crankshaft bearings – replacement
Remove:
• The crankshaft complete from the crankcase.
1
Pull the crankshaft bearing off of the crankshaft
using a bearing puller (see gure 67).
2
Place a new bearing on the shaft and push into
position using tool 502 50 30-22 (see gure 68).
Fig 67
50 – English
Fig 68
7.27 Crankshaft complete – reassembly
1
Fit the crankshaft complete in the crankcase.
Ret the following parts:
• piston and cylinder*
• handle system
• hand guard
• silencer*
• carburettor*
• centrifugal clutch*
• starter assembly*
• cylinder cover
• clutch cover
• chain and bar
* See special instructions.
Repair instructions
7.28 Repairing damaged threads
A repair kit, 503 27 33-01, is available for repairing
damaged threads.
First drill out the hole using:
6,1 mm drill bit for plastic crankcase
Then screw in the thread insert using a suitable
bolt and spanner.
This type of thread insert is best suited for use
in plastic and magnesium, but not for repairing
threads in aluminium. In that case use a helicoil
insert with metric screw (see gure 69).
Fig 69
English – 51
Repair instructions
7.29 Replacing the bar bolt
Replacing the front bar guide.
1
Drain the oil tank.
2
Knock through the old guide bar bolt so that it falls
into the oil tank.
3
Remove the bolt from the oil tank.
4
Secure steel wire to the outer part of the bar bolt
(A), thread the steel wire through the oil tank and
out through the bolt hole in the crankcase (see
gure 70).
5
Pull the steel wire so the bolt comes out of its hole
(see gure 71).
Fig 70
6
Check that the bolt's square head ts in
the washer (D) which is positioned in the cut-out in
the crankcase.
7
Pull out the bar bolt with its nut. Place a spacer
between the nut and crankcase (see gure 71).
8
Rell with chain oil.
Replacing the rear bar guide
1
Pull out the bar guide (C) with the help of slip-joint
pliers (see gure 70).
2
Fit the bar guide with the help of a hammer.
Fig 71
52 – English
Troubleshooting
8 Troubleshooting
Contents
8.1 Troubleshooting ..............................................................................................................54
8.2 Troubleshooting methods ...............................................................................................55
English – 53
Troubleshooting
8.1 Troubleshooting
The various faults that can affect a chainsaw are divided into four groups. In each group the likely
symptoms are given on the left and possible causes are listed on the right. The most likely faults are given
rst, and so on.
Starting
Idling (low rpm) (cont.)
Difculty starting
Carburettor
leaking fuel
Flooding when
engine not
running
Adjust L screw
Air lter blocked
Choke not working
Worn choke pivot
Worn choke valve
Fuel lter blocked
Fuel line blocked
Piston ring seized
Blocked impulse channel
Loose or faulty fuel pipe
Hole in diaphragm
Worn needle valve
Needle valve assembly sticking
Needle valve set too high
Leak in metering system (air
or fuel)
Loose cover on carburettor
pump side
Worn needle valve
Needle valve set too high
Needle valve assembly sticking
Idles when L
screw closed
Idling uneven
Worn needle valve
Leaking control diaphragm/cover
plate
Needle valve assembly sticking
Worn needle valve lever
Faulty diffuser jet
Fuel lter blocked
Fuel line blocked
Leaking air intake hose (rubber)
Loose carburettor mounting
bolts
Worn throttle valve pivot
Loose throttle valve screw
Worn throttle valve
Needle valve assembly sticking
Leak in metering system (air
or fuel)
Metering system centre knob
is worn
Hole in diaphragm
Leaking control diaphragm/cover
plate
Crankcase leaking
Idling (low rpm)
Will not idle
Idling too rich
Adjust L screw
Leaking air intake hose (rubber)
Loose carburettor mounting
bolts
Loose or faulty fuel hose
Fuel lter blocked
Fuel line blocked
Fuel tank vent blocked
Throttle valve pivot stiff
Throttle pushrod sticking
Defective throttle return spring
Bent throttle stop
Faulty diffuser jet
Adjust L screw
Worn needle valve
Needle valve set too high
Worn needle valve lever
Leaking control diaphragm/cover
plate
Needle valve assembly sticking
L screw requires
constant adjustment
Too much fuel at
idling
Fuel line blocked
Needle valve set too high
Needle valve assembly sticking
Leak in metering system (air
or fuel)
Leaking control diaphragm/cover
plate
Faulty diffuser jets
Crankcase leaking
Needle valve set too high
Needle valve assembly sticking
Metering system damaged
Worn needle valve
Leaking control diaphragm/cover
plate
Metering system incorrectly
assembled
54 – English
Troubleshooting
High rpm
Will not run at
full throttle
Low power
Will not “fourstroke”
Adjust H screw
Blocked air lter
Blocked fuel tank vent
Blocked fuel lter
Fuel line blocked
Loose or damaged fuel hose
Impulse channel leaking
Impulse channel blocked
Loose cover on carburettor pump
side
Faulty pump diaphragm
Leaking air intake hose (rubber)
Loose carburettor mounting bolts
Needle valve set too low
Metering system damaged
Metering system incorrectly
assembled
Leaking control diaphragm/cover
plate
Needle valve assembly sticking
Blocked silencer
Adjust H screw
Blocked fuel tank vent
Blocked fuel lter
Impulse channel leaking
Impulse channel blocked
Loose cover on carburettor pump
side
Faulty pump diaphragm
Blocked air lter
Needle valve assembly sticking
Leak in metering system (air or
fuel)
Metering system incorrectly
assembled
Loose diaphragm rivet
Hole in diaphragm
Leaking control diaphragm/cover
plate
Blocked fuel tank vent
Blocked fuel lter
Fuel line blocked
Loose or damaged fuel hose
Impulse channel leaking
Impulse channel blocked
Loose cover on carburettor pump
side
Faulty pump diaphragm
Leaking air intake hose (rubber)
Loose carburettor mounting bolts
Needle valve set too low
Leak in metering system (air or fuel)
Metering unit incorrectly assembled
Loose diaphragm rivet
Hole in diaphragm
Leaking control diaphragm/cover
plate
Acceleration och retardation
Does not
accelerate
Engine stalls
when throttle
released
Over rich
acceleration
Adjust L screw
Adjust H screw
Blocked air lter
Blocked fuel tank vent
Blocked fuel lter
Fuel line blocked
Loose or damaged fuel hose
Impulse channel blocked
Loose cover on carburettor pump
side
Faulty pump diaphragm
Leaking air intake hose (rubber)
Loose carburettor mounting bolts
Needle valve set too low
Metering system incorrectly
assembled
Needle valve assembly sticking
Faulty diffuser jets
Blocked silencer
Adjust L screw
Adjust H screw
Faulty pump diaphragm
Needle valve set too high
Needle valve assembly sticking
Faulty diffuser jets
Adjust L screw
Adjust H screw
Blocked air lter
Faulty pump diaphragm
Faulty diffuser jets
8.2 Troubleshooting methods
In addition to the faults described in the above
table, trouble shooting can be carried out on
specic components or sub-systems of the
chainsaw. The various procedures are described
in the relevant chapters, see the contents page, as
follows:
• Checking the operation of the chain brake
• Measuring the resistance of the stop plate
• Pressure testing the carburettor
• Pressure testing the decompression valve
• Pressure testing the cylinder
English – 55
510 16 77-26
2009W39
Loading...