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MAINTENANCE
Carburetor
Your Husqvarna product has been designed and manufactured
to specifications that reduce harmful emissions.
After your unit has been run 8-10 tanks of fuel the engine has
broken in. To ensure that your unit is at peak performance and
producing the least amount of harmful emissions after break in,
have your authorized servicing dealer, who has a revolution
counter at his disposal, to adjust your carburetor for optimum
operating conditions.
!
Functioning, Basic setting, Final setting
WARNING! Do not start the saw without the
bar, chain and clutch cover (chain brake)
assembled. If you do, the clutch might come
loose and cause severe injuries.
Operation
• The carburetor governs the engine speed via the throttle. Air/
fuel are mixed in the carburetor. The air/fuel mixture is
adjustable. To take advantage of the saw’s maximum output
the setting must be correct.
• Adjusting the carburetor means the engine is adapted to local
operating conditions, e.g. climate, altitude, petrol and the type
of 2-stroke oil used.
• The carburetor is equipped
with two adjustment
possibilities:
L = Low speed needle
T = Idling speed adjuster
screw
(The max. speed is
controlled by a fixed needle/
electronic speed governor).
• The fuel quantity required in relation to the air flow permitted
by the throttle opening is adjusted using the low speed
needle. Turning the needle clockwise gives a leaner fuel
mixture (less fuel) and turning it anti-clockwise gives a richer
fuel mixture (more fuel). A leaner mixture gives high revs
while a richer mixture give less revs.
• The T screw regulates the idling speed. If the screw T is
turned clockwise this gives a higher idling speed; anti-
clockwise a lower idling speed.
Basic setting and running in
The carburetor is set to its basic setting when test run at the
factory. The basic setting is richer than the optimal setting and
should be kept during the machine‘s first working hours.
Thereafter the carburetor should be finely adjusted. Fine
adjustment should be carried out by a skilled technician.
NOTE! If the chain rotates while idling the T screw should be
adjusted counter-clockwise until it stops.
Recommended idling speed: 2 500 rpm.
Fine adjustment
• When the saw has been ”run-in” the carburetor should be
finely adjusted. The fine adjustment should be carried out
by qualified person. The L-needle is adjusted first, then the
idling screw T.
Conditions
• Before any adjustments are made the air filter should be
clean and the cylinder cowling fitted. Adjusting the carburetor
while a dirty air filter is in use will result in a leaner mixture
when the filter is finally cleaned. This can give rise to serious
engine damage.
• Turn the low speed needle clockwise until it bottoms. Now
turn it one turn anti-clockwise. The carburetor is set to L = 1.
• Do not attempt to adjust the needles beyond the stops as
damage can occur.
• Now start the saw according to the starting instructions and
run it warm for 10 minutes.
NOTE! If the chain rotates the T screw should be turned
anti-clockwise until the chain stops.
• Place the saw 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 needle L
Try to find the highest idling speed, turning the low speed
needle L clockwise respectively counter-clockwise. When the
highest speed has been found, turn the low speed needle L 1/4
turn counter-clockwise.
NOTE! If the chain rotates in the idling position, turn the
idling speed screw counter-clockwise until the chain stops.
Final setting of the idling speed T
Adjust the idling speed with the screw T. If it is necessary to re-
adjust, first turn the idle speed adjusting screw T clockwise, until
the chain starts to rotate. Then turn, counter-clockwise until the
chain stops. A correctly adjusted idle speed setting occurs
when the engine runs smoothly in every position. It should also
be good margin to the rpm when the chain starts to rotate.
High speed jet H
This saw is equipped with a
carburetor that has an
integrated, fixed high speed
jet.
NOTE! There is an
integrated speed governor
in the ignition that limits the
maximum speed 12 000 rpm.
Therefore adjusting the jet
does not affect the maxi-
mum speed. The high speed
jet affects the saw’s power.
WARNING Setting the high speed jet to lean reduces the
engine’s power and causes overheating. This results in engine
damage.
Correctly adjusted carburetor
A correctly adjusted carburetor means that the saw accelerates
without hesitation and the saw 4-cycles a little at max speed.
Furthermore, the chain must not rotate at idling. A too lean
adjusted low speed needle L may cause starting difficulties and
bad acceleration.
A too lean setting on the H jet gives the saw lower power = ”less
strength”, bad acceleration and/or engine damage. A too rich
setting on the L-needle results acceleration problems or a too
low working speed.
Contact your servicing dealer, if the idle speed
setting cannot be adjusted so that the chain
stops. Do not use the saw until it has been
properly adjusted or repaired.
!
Contact your servicing dealer, if the idle
speed setting cannot be adjusted so that the
chain stops. Do not use the saw until it has
been properly adjusted or repaired.
!
H