Husqvarna 550XP User Manual

Page of 44
MAINTENANCE
English
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 29
General
The user must only carry out the maintenance and 
service work described in this Operator’s Manual. More 
extensive work must be carried out by an authorized 
service workshop.
Carburettor adjustment
Your Husqvarna product has been designed and 
manufactured to specifications that reduce harmful 
emissions. 
AutoTune
If the engine is equipped with AutoTune, manual 
adjustment of the carburettor’s H and L needles and the T-
screw no longer applies. Both needles and the T-screw 
have been removed. AutoTune is a function that adjusts 
the carburettor electronically, always resulting in optimal 
adjustment.
Function
The carburettor controls the speed of the engine via 
the throttle. Air/fuel is mixed in the carburettor. This air/
fuel mixture is adjustable.
The automatic adjustment of the carburettor means 
that the engine is adapted to local conditions, e.g. the 
climate, altitude, petrol and the type of 2-stroke oil. 
This function is controlled by AutoTune.
Engine adjustment
The following steps should be taken when the chain saw 
is started for the first time or when outside circumstances 
change (fuel, altitude, air filter etc.): Start the engine. 
Accelerate the engine to full throttle and saw a number of 
cuts in a thick log (3-5 min.).
The chain saw must be run (8,000 - 12,000 rpm) the entire 
time so that the carburettor can adjust itself.
Conditions
NOTE! The ignition system includes an in-built speed 
limiter. When the speed governor is activated, you will get 
the same sound experience as when the chain saw 4-
cycles.
Checking, maintaining and 
servicing chain saw safety 
equipment
Chain brake and front hand guard
Checking brake band wear
Brush off any wood dust, resin and dirt from the chain 
brake and clutch drum. Dirt and wear can impair operation 
of the brake.
Regularly check that the brake band is at least 0,6 mm 
thick at its thinnest point.
Checking the front hand guard
Make sure the front hand guard is not damaged and that 
there are no visible defects such as cracks.
Move the front hand guard forwards and back to make 
sure it moves freely and that it is securely anchored to the 
clutch cover.
Note! All service and repair work on the machine 
demands special training. This is especially true of the 
machine’s safety equipment. If your machine fails any of 
the checks described below we recommend that you 
take it to your service workshop.