Husqvarna 1153177-26, Operator'S Manual

Page: 29 / 44

MAINTENANCE
English
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29
Carburettor adjustment
The carburettor can be designed in different ways,
depending on existing environmental and emissions
legislation. Some chain saws are equipped with
movement limiters on the carburettor’s adjuster screws.
These limit the adjustment possibilities to a maximum of a
1/2 turn.
When your chain saw is equipped with a carburettor that
features movement limiters, the carburettor should be
adjusted according to the instructions under the heading
Carburettor with movement limiters.
When your chain saw is equipped with a carburettor that
does not feature movement limiters, the carburettor
should be adjusted according to the instructions under the
heading Carburettor without movement limiters.
Contact your servicing dealer (retailer) if you are
uncertain of which type of carburettor your chain saw
is equipped with.
Carburettor with movement
limiters
Your Husqvarna product has been designed and
manufactured to specifications that reduce harmful
emissions.
Function, Basic settings, Fine adjustment
Function
• 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.
• 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.
• The carburettor has three adjustment controls:
- L = Low speed jet
- H = High speed jet
- T = Idle adjustment screw
• 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.
• 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. Avoid running at a too high speed during the
first 10 hours.
CAUTION! If the chain rotates while idling the T-screw
must be turned anti-clockwise until the chain stops.
1/2
1/2
H
L
H
L
1/2
1/2
H
L
!
WARNING! Do not start the chain saw
unless the bar, chain and clutch cover
(chain brake) are fitted, otherwise the
clutch may come loose and cause
personal injury.