Basic Setting; Fine Adjustment; L-Needle; H-Needle - Husqvarna 525L Workshop Manual

Basic setting

The carburettor is set to its basic setting when test
run at the factory. The basic setting is "richer" than
the optimal setting and should be kept during the
engine's first working hours. Thereafter the carbu-
rettor should be fine tuned.
The default setting is:
H = 2 1/2 revolution open
L = 2 1/2 revolution open
The following conditions apply to all carburettor
settings in order to achieve the correct result:
• Defect-free spark plug with correct electrode
gap.
• Defect-free air filter. Clean and correctly fitted.
• There should be no leaks between the cylinder
and the distance piece and the carburettor and
the insulator. Check the screws are tight.
• The fuel filter should be clean.
•
The exhaust port (muffler and cylinder) should not be
completely or partially clogged.
• The cutting attachment (blade or trimmer head)
must be fitted. The cord length must be as
standard (cut by the cutter on the splash guard).
• Correct fuel quality, minimum 89 octane.
Carefully screw in (clockwise) the L- and H-jets until they
bottom. Now unscrew (counterclockwise) the jets to the
default setting.
Use tool 530 03 55-60.

Fine adjustment

Fine adjustment of the carburettor should be
carried out after the engine has been "run-in".
The engine must also be run warm for 4 minutes.
The carburettor setting must be carried out in two
steps.
With a trimmer head
(Use Husqvarna T35 trimmer head with silent cord
∅ 2.4 mm. The length of the trimmer cord will be
adjusted by the knife on the original cutting attach-
ment guard).

L-needle

Step 1: Turn the needle clockwise for the position
providing maximum engine speed.
Step 2: Then turn the needle counterclockwise
so that the speed drops by 700 rpm (from maxium
speed (richer setting).

H-needle

Step 1: Turn the needle counterclockwise the
position where the engine speed become 9150
rpm.
Step 2: Turn the needle 1/4 of a turn clockwise
(leaner setting).
NOTE!
Speed in excess of 11,000 rpm should be
restricted by the ignition system and not
recorded by the revolution counter.
Start the engine and check it responds quickly at
full throttle, the idle speed is to be adjusted to 3000
rpm if necessary.
NOTE!
If the cutting attachment rotates when the
engine is idling, the idle adjustment screw T
should be turned counterclockwise until the
cutting attachment stops.
Repair instructions
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