Husqvarna 250R - Manual (Page 31)

English – 31
MAINTENANCE
Setting procedure with a load (Trimmer head
should be used)
Ensure the length of the trimmer cord is correct, i.e. exactly
reaches the knife on the trimmer guard. Use either 3 mm or
3.3 mm diameter trimmer cord.
Run the machine warm for about 5 minutes mostly at full
throttle. When the carburettor is to be adjusted, apply full
throttle and turn the H-needle anti-clockwise until the engine
burbles or until the cap reaches its stop position. (If the engine
runs smoothly when the cap is in its stop position no further
adjustment is necessary!) Turn the H-needle slowly clockwise
until the engine runs absolutely smoothly. (Burbling has
stopped completely). Now screw the H-needle (anti-
clockwise) a few tenths of a turn.
CAUTION! For optimum adjustment of the carburettor,
contact a qualified dealer/service workshop that has a
revolution counter at their disposal.
265RX
The machine is equipped with fixed L and H-needles, in order
to ensure that the machine always receives the correct
mixture of fuel and air.
When the engine lacks power or accelerates poorly, proceed
as follows:
• Check the air filter and replace if necessary.
• When this does not help, contact an authorised service
workshop. The needles are available in different sizes.
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.
Correctly adjusted carburettor
When the carburettor is correctly adjusted the machine will
accelerate without hesitation and burble a little at maximum
speed. It is also important that the cutting attachment does
not rotate at idle. If the low speed jet L is set too lean it may
cause starting difficulties and poor acceleration.
If the high speed jet H is set too lean it will result in less power,
less performance, poor acceleration and/or damage to the
engine.
If both the L and H jets are set too rich it will results in
acceleration problems or too low a working speed.
Muffler
CAUTION! Some mufflers are fitted with a catalytic converter.
See chapter on Technical data to see whether your machine
is fitted with a catalytic converter.
The muffler is designed to reduce the noise level and to direct
the exhaust gases away from the operator. The exhaust
gases are hot and can contain sparks, which may cause fire
if directed against dry and combustible material. Some
mufflers are equipped with a special spark arrestor mesh. If
your machine has this type of muffler, you should clean the
mesh at least once a week. This is best done with a wire
brush. On mufflers without a catalytic converter the mesh
should be cleaned weekly, or replaced if necessary. On
mufflers fitted with a catalytic converter the mesh should be
checked, and if necessary cleaned, monthly. If the mesh is
damaged it should be replaced.
If the mesh is frequently blocked, this can be a sign that the
performance of the catalytic converter is impaired. Contact
your dealer to inspect the muffler. A blocked mesh will cause
the machine to overheat and result in damage to the cylinder
and piston.
CAUTION! Never use a machine with a defective muffler.
H
!
WARNING! Mufflers fitted with catalytic
converters get very hot during use and
remain so for some time after stopping. This
also applies at idle speed. Contact can result
in burns to the skin. Remember the risk of
fire!
250R/252RX
265RX