MAINTENANCE
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.
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.
H
Air filter
The air filter should be cleaned regularly removing dust and dirt to avoid: � Carburettor malfunction � Starting problems � Reduced engine power 2 � Unnecessary wear to engine parts 1 � Abnormal fuel consumption
� 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.
A
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. 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!
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.
B
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.
