18 – English
MAINTENANCE
Fuel filter
• The fuel filter sits inside the fuel tank.
• The fuel tank must be protected from contamination when
filling. This reduces the risk of operating disturbances caused
by blockage of the fuel filter.
• The filter cannot be cleaned but must be replaced with a new
filter when it blocked. The filter should be changed at least
once per year.
High speed needle H
• The carburettor is equipped
with an automatic speed
governor, which prevents a
too high peripheral speed
on the cutting disc. At full
throttle with a unloaded
cutting disc distinctive
variations in speed can be
heard. This is usual and is
only a sign that the speed
governor is working.
• The high speed needle H
affects the power cutter’s
output and should be set
according to the
recommended basic setting,
H = 3/4 turn open.
• If adjustment is necessary proceed as follows:
Screw the H-needle inwards to the limit position where the
engine starts to hesitate with acceleration. Use short, fast
acceleration from idling. From this position the H-needle is
opened 1/4 turn (90°), which gives the carburettor setting for
max. engine output.
• Check using a tachometer that the stated maximum speed
10,000 rpm is not exceeded.
NOTE! A high speed needle set too lean (H-needle screwed in
too far)) reduces the power cutter’s output and causes
overheating resulting in engine damage. The high speed
needle H should be set for the highest output and not the
highest speed.
NOTE! Too obtain the optimal setting a technician with access
to a tachometer should be contacted. The recommended
maximum speed should not be exceeded.
Correctly adjusted carburettor
A correctly adjusted carburettor means that the machine
accelerates without hesitation and that the engine gurgles a
little at full throttle. In addition the cutting disc should not rotate
when idling. An L-needle set too lean can give starting
difficulties and inferior acceleration. An H-needle set too lean
gives lower engine output = ”less power”, inferior acceleration
and/or engine damage. A too rich setting of either the L or H
needles gives acceleration difficulties or a too low working
speed.
2) The main filter is a paper filter and is accessible from under
cover B. This filter should be changed/cleaned when the
engine’s output drops or after 1-2 weeks. The filter is
cleaned by shaking or carefully using compressed air. Note
the filter must not be washed!
A filter used for a long period of time can never be completely
cleaned. Therefore all air filters must be replaced periodically
with a new filter. A damaged air filter must always be
replaced.
2
H
1
A
Air filter
The air filter should be cleaned regularly removing dust and dirt
to avoid:
• Carburettor malfunction
• Starting problems
• Reduced engine power
• Unnecessary wear to
engine parts
• Abnormal fuel consumption
The air filter system consists
of a pre-filter and a main filter:
1)The pre-filter is an oiled
foam filter that is easily
accessible under the filter
cover (A). When used in
dusty conditions, this filter
should be checked/replaced
after every second tank of
fuel. The filter must be
cleaned and oiled regularly
to obtain a satisfactory
filtering effect. There is a
special HUSQVARNA oil
produced for this purpose
(reference number 503 47
73-01). The bottle contains
sufficient oil (0.1 l) for oiling
the filter three times.
• Remove the filter. Wash the
filter carefully in tepid,
soapy water. After cleaning
rinse the filter thoroughly in
clean water. Squeeze out
the filter and let the filter
dry.
NOTE! Compressed air at a
high pressure can damage
the foam.
• Oil the filter carefully. It is
extremely important that the
entire filter is saturated in
oil.
B