Husqvarna 240RBD Operator'S Manual Download

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MAINTENANCE

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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.

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 1/4
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.

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.

Rec. idling speed: 2 700 rpm.
Recommended max. speed:

See “technical data”

WARNING!
If the idling speed cannot be adjusted so
that the cutting attachment stops,
contact your service workshop. Do not
use the machine until it has been
correctly adjusted or repaired.

WARNING!
The complete clutch cover with shaft
must be fitted before the machine is
started, otherwise the clutch can become
loose and cause personal injury.

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

• 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.

H L