Husqvarna 455 Chainsaw User Manual


 
MAINTENANCE
English 31
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 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 carb
urettor 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
thic
k 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 mo
ves freely and that it is securely anchored to the
clutch cover.
!
WARNING! If the saw chain rotates while
idling, contact your servicing dealer. Do
not use the chain saw until it has been
properly adjusted or repaired.
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.