Husqvarna 390 XP G Operator's Manual page 25

2. Make sure that the muffler is correctly attached to
the product.
3. If your product has a special spark arrestor mesh,
clean the spark arrestor mesh weekly.
4. Replace a damaged spark arrestor mesh.
CAUTION: If the spark arrestor mesh is
blocked the product becomes too hot and
this causes damage to the cylinder and
piston.
Carburetor adjustment
Because of environmental and emissions laws, your
product has adjustment limitations on the carburetor
adjuster screws. This decreases the harmful exhaust
fumes from your product. You can only turn the
adjustment screws maximum ½ turn.
590 - 002 - 04.06.2020
Basic adjustments and run-in
The basic carburetor adjustments are done at the
factory. For the recommended idle speed, refer to
Technical data on page 34 .
To adjust the low speed needle (L)
• Turn the low speed needle clockwise until stop.
Note: If the product has a bad acceleration capacity
or if the idle speed is not correct, turn the low speed
needle counterclockwise. Turn the low speed needle
until the acceleration capacity and idle speed is
correct.
To adjust the idle speed screw (T)
1. Start the product.
2. Turn the idle speed screw clockwise until the saw
chain starts to rotate.
3. Turn the idle speed screw counterclockwise until the
saw chain stops.
Note: The idle speed is correctly adjusted when the
engine runs correctly in all positions. The idle speed
must also be safely below the speed at which the saw
chain starts to rotate.
To adjust the high speed needle (H)
The engine is adjusted at the factory to operate at sea
level. At higher altitudes, in different weather or different
temperatures it can be necessary to adjust the high
speed needle.
• Turn the high speed needle to make adjustments.
1/2
1/2
To examine if the carburetor is correctly
adjusted
• Make sure that the product has the correct
acceleration capacity.
CAUTION: Do not operate the product at too
high speed during the first 10 hours of
operation.
CAUTION: If the saw chain rotates at idle
speed, turn the idle speed screw
counterclockwise until the saw chain stops.
WARNING: If the saw chain does not stop
when you turn the idle speed screw, speak
to your servicing dealer. Do not use the
product until it is correctly adjusted.
CAUTION: Do not turn the high speed
needle screw across the adjustment
limitation stop. This can cause damage
to the piston and the cylinder.
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