MAINTENANCE
English
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31
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Place the machine on a flat surface so that the bar
points away from you and so that the bar and chain do
not come into contact with the surface or other
objects.
Low speed jet L
Turn the low speed jet L clockwise until it stops. If the
engine accelerates poorly or idles unevenly, turn the low
speed jet L anticlockwise until good acceleration and
idling are achieved.
Fine adjustment of the idle speed T
Adjust the idle speed with the T-screw. If it is necessary to
re-adjust, turn the T-screw clockwise while the engine is
running, until the chain starts to rotate. Then turn anti-
clockwise until the chain stops. When the idle speed is
correctly adjusted the engine should run smoothly in
every position and the engine speed should be safely
below the speed at which the chain starts to rotate.
High speed jet H
At the factory the engine is adjusted at sea level.
When working at a high altitude or in different
weather conditions, temperatures and atmospheric
humidity, it may be necessary to make minor
adjustments to the high speed jet.
CAUTION! If the high speed jet is screwed in too far,
it may damage the piston/cylinder.
When test run at the factory, the high speed jet is set so that
the engine satisfies the applicable legal requirements at the
same time as achieving maximum performance. The
carburettor’s high speed jet is then locked using a limiter cap
in the fully screwed out position. The limiter cap limits the
potential to adjust the high speed jet to at most half a turn.
Correctly adjusted carburettor
When the carburettor is correctly adjusted the machine
accelerates without hesitation and 4-cycles a little at full
throttle. It is also important that the chain does not rotate
at idle. If the L-jet is set too lean it may cause starting
difficulties and poor acceleration. If the H-jet is set too
lean the machine will have less power, poor acceleration
and could suffer damage to the engine.
Carburettor without movement
limiters
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The carburettor governs the engine’s speed via the
throttle control. Air and fuel are mixed in the
carburettor. The air/fuel mixture is adjustable. Correct
adjustment is essential to get the best performance
from the machine.
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The satisfactory operation of a catalytic converter
depends, among other factors, on the correct
adjustment of the carburettor. Carefully follow the
instructions below, using a tachometer as an aid.
•
Adjusting the carburettor means that the engine is
adapted to local operating conditions, e.g. climate,
altitude, petrol and the type of 2-stroke oil.
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The carburettor has three adjustment controls:
- L = Low speed jet
- H = High speed jet
- T = Idle adjustment screw
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The L and H-jets are used to adjust the supply of fuel
to match the rate that air is admitted, which is
controlled with the throttle. If they are screwed
clockwise the air/fuel ratio becomes leaner (less fuel)
and if they are turned anti-clockwise the ratio
becomes richer (more fuel). A lean mixture gives a
higher engine speed and a rich mixture gives a lower
engine speed.
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The T-screw regulates the throttle setting at idle
speed. If the T-screw is turned clockwise this gives a
higher idle speed; turning it anti-clockwise gives a
lower idle speed.
Basic settings and running in
The basic carburettor settings are adjusted during testing
at the factory.
The basic settings are H = 1 turn and L = 1 turn. To
provide the engine’s components with good initial
lubrication (during running in) the carburettor should be
set for a richer fuel mixture for the first 3-4 hours that the
chain saw is in use. To do this, adjust the fast idle speed
to 600-700 rpm below the recommended maximum fast
idle speed.
If you are unable to check the fast idle speed using a
tachometer the H-jet should not be set for a leaner mixture
than given in the basic settings. The recommended
maximum fast idle speed must not be exceeded.
CAUTION! If the chain rotates while idling the T-screw
must be turned anti-clockwise until the chain stops.
Rec. idle speed: 2700 rpm
!
WARNING! Contact your servicing
dealer, if the idle speed setting cannot be
adjusted so that the chain stops. Do not
use the chain saw until it has been
properly adjusted or repaired.
H
L
L
H
T
