For Husqvarna Parts Call 606-678-9623 or 606-561-4983
Workshop
manual
chain saw model
181
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101 88 11-26
For Husqvarna Parts Call 606-678-9623 or 606-561-4983
Contents
1 ■ TechnicalData
2■ ServiceData
■ SpecialTools
3
4■ Fuelsystem
■ Electricsystem
5
■ Lubricatingsystem
6
7■ Cylinder,Piston
■ Crankcase,Crankshaft
8
■ Starter
9
—
—
.
3
5
7
11
17
1
23
_
33
10 w
11
■ SafetyEquipment
CentrifugalClutch—
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35
37
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Displacement
Bore
Stroke
Poweroutput
Ignitionsystem
Ignitionadvance
Air gap
Sparkplugtype
Electrodegap
80.7 cm3 (4.9 cu in)
52.0 mm (2.05”)
38.0 mm (1 .5”)
4.0 kW (5.5 hp) at 140 r/s (8.400 r/rein)
Make SEM type AM 7
25° before t.d.c. at 142 r/s (8.500 r/rein)
0.30 mm (0.01 2“)
Champion RCJ 7Y
0.5 mm (0.020”)
Technical Data ■
1
Handleheating
(181SG)
Carburetor
Fueltank volume
Oiltankvolume
Chain lubrication
Clutchdrum/sprocket
Weights
Weight sawbody incl. chain brake (empty)
Weight sawbody (empty) incl. chain brake and
18“ bar and chain
56 watts at 120 r/s (7.200 r/rein)
Diaphragm carburetor make Tillotson type HS 216
Basic setting:
H = 1.0
L = 1.0
0.85 Iitres (0.22 US gallon, 0.19 Imp gallon).
Fuel mixture 4% (1 :25)
With Husqvarna Twostroke Oil 2% (1 :50)
0.50 Iitres (0.13 US gallon, 0.11 Imp gallon)
Automatic. No supply during idling. Adjustable for 4 different delivery rates.
Recommended ~ositions:
Bar 18“;
Bar 20” and more: Pos. 3–4
Standard 7 teeth. Optional 8 teeth. 3/8” pitch.
6.8 kg
8.2 kg
Pos. 2
15.0 lb
18.1 lb
7.0 kg 15.4 lb
8.4 kg
18.5 lb
Classificationtable
C c
A
B
c
PLEASE NOTE!
As “A” denotes smallest cylinder diameter and “C’” the largest, piston grades
should be matched or one grade smaller. Eg it is not permissible to use a grade
B piston in a grade A cylinder.
P c
A
B
c
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Service Data ■
CrankcaseAssy
v 0.04 MPa (0.4 kp/cm2, 5.7 psi)
l 0,01 MPa/1 min (0.1 kp/cm2, 1.4 psi per rein)
TOOIS: 5025037-01 Vacuum gauge
5025047-01 Cover plate, inlet port
5025081-01 Cover plate, exhaust port
P 0.08 MPa (0.8 kp/cm2, 11.4 psi)
l 0.02 MPa/30 sec (0.2 kp/cm2, 2,8 psi per 30 see)
TOOIS: 5025038-01 Pressure gauge
5025047-01 Cover plate, inlet port
5025081-01 Cover plate, exhaust port
2
Fueltank
PreSSUre: 0.05 MPa (0.5 kp/cm2, 7.
L No leakage permitted
: 5025038-01 Pressuregauge
I p
Starter
Make sure that it is possible to turn the pulley at least about 1/4 turn further
when the cord is pulled out completely.
Carburetor
p 0.03 MPa (0.3 kp/cm2, 4.3 psi)
L No leakage permitted
.
: 5025038-01 Pressuregauge
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—
Special Tools ■
5
Assembling pliers,
f
N
o
spark plug protector
5 4
5 3
5 3
Allen key
@p@
9
~:i: ‘[ “
@
- ,,,$*
@
5
Puller compl. with screw
5
Fitting tool compl. for
crankshaft and sealing ring
\
3
T
H
5
Ball bearing puller compl.
5
Stud fitting tool
5
Piston sto~
R
5 8
5
Socket spanner
5
Revolution counter
5
Holding bar compl.
/
.
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5
Vacuum gauge compl.
7
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5 3
5 4
Allen screwdriver with ball
!
)
~..
R
a C,ampingdevice
5
Retouch paint, orange 1/8 I
5
..
d
Special Tools ■
5
SEM electric system tester
5
Air gap tool
5
Extractor sealing ring
3
A
b
&
5
Glue, adhesive
5
5
Loctite AA (normal locking power)
5
Loctite AAV (strong locking power)
%
Q
5
Puller for engineblock
5
Fitting drift, sealing ring
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2
■ Service Data
Chainbrake
.
When used with a 18“ guide bar the Swed-o-Matic should release at a load on
the bar tip of 12–17 kp (26–37 lb).
Replace the brake band as soon aswear has reduced its original thickness by
more than
band thickness.
25~0, i.e. at least 0,75 mm (0.03”) must be left of the original
Fueland oil
The twostroke engine is lubricated by oil mixed with petrol in various proportions depending on the type of oil used:
Ordinary twostroke oil
Husqvarna Twostroke oil
See also the mixing table below:
M t
1:25 (4% oil)
1:50 (2% oil)
Mixing table 2%
Litres Pints Litres
of oil
0.2 0.35 10
0.4 0.70 20
1.0 1.76 50
of oil of petrol Imp gallon US gallon of petrol Imp gallon USgallon
Petrol in
11.0 13.2 25
2,2
4.4
Petrol in
2.6 5
5.2 10
Litres
4%
Petrol in
1.1
2.2 2.6
5.5
Petrol in
1,3
6.6
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Fuelsystem I
4
Removalof carburetor
Remove the air filter and the fuel hose.
Remove the throttle push rod from the plastic lever with a pair of flat hose
pliers.
Remove the stop switch in order to get at the left screw that retains the carburetor,
Push out the choke control from the lever on the carburetor.
Loosen the screw that connects the air filter elbow to the crankcase.
Loosen the socket head screwsthat retain the carburetor (use the Allen key
No. 502501 8-01) and lift the carburetor off together with the air filter elbow and the screws.
Clean the carburetor on the outside.
Remove the metering diaphragm cover and the metering diaphragm.
Note that the centre pin of the diaphragm enters the forked end of the lever of
the needle valve,
Connect the pressure gauge 5025038-01 to the fuel inlet of the carburetor
and pump until a pressureof 0.03 MPa (0.3 kp/cm2 ) is reached.
Check for any leakage at the needle valve or at the gasket on the pump side.
The easiest way of locating leakages is to pour some petrol where you suspect
the leakages to be.
Loosen the screw that retains the bearing shaft of the lever and remove lever,
shaft, spring and needle valve.
Drill a small hole in the welch plugs (approx. @ 2 mm) and prise away the plugs
by means of a pointed tool.
NOTE! Drill with care in order not to damage the carburetor housing.
Unscrew the two adjusting needles.
Remove the cover above the pump diaphragm and remove diaphragm and
gasket.
Lift off the fuel screen carefully by means of a pointed tool.
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■ Special Tools
3
5
Pressuregauge compl.
\
R
%
0
o:
o
*
5
Distance sleeve (57 mm)
5
Cover plate, inlet port
\
,--’
5
Cable clip pliers
5
Fitting sleeve for
sealing ring
5
U-spanner for vibration
damper
o
\
\
Q
‘,
&
T
5
Cover plate, exhaust port
o
/
5
’
Assembling pliers,
centrifugal clutch
5
Repair kit for elec-
tric cables
4
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5
Hook for fuel filter
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4Fuel system ■
When properly adjusted the lever of the needle valve shall be on a level with the
carburetor housing surrounding it.
If the lever is located too high, the carburetor will be very sensitive as regards
the adjustment of the adjusting needles,
A too low lever induces bad acceleration qualities.
Check that the lever can move freely.
Make a pressure test of the carburetor. Proceed as mentioned above,
Then mount gasket, metering diaphragm and cover.
NOTE!
Care should be taken to ensure that the centre pin of the diaphragm
enters the fork in the lever!
Install the adjusting needles and screw them out to the following basic posi-
tion: H = 1.0 turn open. L = 1.0 turn open.
Adjustmentof carburetor
B s
D
Before adjusting the carburetor, proceed as follows:
. Clean the air filter or, if necessary, replace it with a new one.
. Check the spark plug and its electrodes.
. Check that the fuel filter is not clogged.
Examine the fuel filter as follows:
Loosen the fuel hose from the carburetor and lay the chain saw on the clutch
side. Open the tank cap, If there is enough fuel in the tank, some of it now
ought to run out of the hose.
.....
‘%,.,
,.,
‘.
After having made the abovementioned checks you make a basic adjustment of
the carburetor needles, i.e. H = 1turn open and L = 1 turn open.
Start the chain saw and warm it
cut into a log.
A constant speed for 10–20 sec indicates not only a good high speed function
of the carburetor but also a good condition overall.
Should there be a sudden lean suPPly to the engine after approx. 10–20 sec
full throttle running (big speed increase), this would indicate some fault in the
fuel system.
The trouble may be caused by:
. Leakage in the pumping section of the carburetor.
. Crack in the insulating piece.
. Loose carburetor bolts.
. Incorrectly assembled or leaking gaskets.
. Tank breather valve inoperative.
. Fuel filter clogged.
u by applying full throttle and letting it
NOTE!
Too lean adjustment of the carburetor would cause a considerable loss
of power. Adjust the carburetor in order to obtain maximum power and
not maximum speed.
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