Maintenance; Carburettor - Husqvarna 359.79509 Operator's Manual

MAINTENANCE
Carburettor
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 carburettor for optimum operating conditions.
Operation
• The carburettor governs
the engine's speed via the
throttle. Air/fuel is mixed
in the carburettor. The
air/fuel mixture is
adjustable. To take
advantage of the engine's
optimal output the
adjustment must be
correct.
• The setting of the
carburettor means that
the engine is adapted to
local conditions, for
example, the climate,
altitude, petrol and the
type of 2-stroke oil.
• The carburettor is
equipped with three
adjustment possibilities:
L = Low
speed needle
H
= High speed needle
T
= Idle speed adjuster
screw
H
L
• The fuel quantity in relation to the air flow permitted by
the throttle opening is adjusted using the
L
and H-needles.
Turning the needles clockwise gives a leaner fuel mixture
(less fuel) and turning them 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 position of the throttle while the
engine is idling. Turning the screw clockwise gives a higher
idling speed while turning it anti-clockwise gives a lower
idling speed.
Basic setting
• The carburettor 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 carburettor should be finely adjusted.
Fine adjustment should be carried out by a skilled
technician.
NOTE!
If the cutting attachment rotates/moves while the
engine is idling the T-screw should be turned anti-clockwise
until the cutting attachment stops.
tec. idling speed: 2 700 rpm.
Recommended max. speed: See "Technical Data".
Fine adjustment
• When the machine has been "run-in" the carburettor should
be finely adjusted. The fine adjustment should be carried
out by qualified person. First adjust the L-jet, then the
idling screw
T
and then the H-jet.
Conditions
• Before any adjustments are made the airfilter should be clean
and the airfilter cover fitted. Adjusting the carburettor while
a dirty airfilter is in use will result in a leaner mixture when
the filter is finally cleaned. This can give rise to serious
engine damage.
• Carefully turn the
L
and
H
needle to the mid point between
fully turned in and fully turned out.
• Do not attempt to adjust the needles beyond the stops as
damage can occur.
• Now start the machine according to the starting instructions
and run it warm for 10 minutes.
NOTE!
If the cutting attachment rotates/moves the
T
screw
should be turned anti-clockwise until the cutting attachment
stops.
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 114
turn counter-clockwise.
NOTE!
If the cutting
attachment rotates/moves in
the idling position, turn the
idling speed screw
T
counter-clockwise until the
cutting attachment stops.
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