Carburettor - Husqvarna 375K Operator's Manual

Carburetor Carburetor
Your Husqvarna product has been designed and manufactured
to specifications that reduce harmful emissions.
After your unit has been run 8-10 tanks of fuel the engine has
broken in. To ensure that your unit is at peak performance and
producing the least amount of harmful emissions after break in,
have your authorized servicing dealer, who has a revolution
counter at his disposal, to adjust your carburetor for optimum
operating conditions.
Functioning, Basic setting, Final setting
!
WARNING! Do not start the power cutter
without the cutting arm or cutting head fitted.
Otherwise the clutch can come loose and
cause personal injury.
Operation
• The carburetor governs the engine speed via the throttle. Air/
fuel are mixed in the carburetor.
Govenor
The engine is equipped with in the ignition built in non
adjustable electronic speed limiter. The limiter prevents the
engine from being ran at a too high RPM.
• The carburetor has three
adjustment possibilities:
L = Low speed jet.
H = High speed jet.
T = Adjustment screw for
idling.
• The T screw regulates the idling speed. If the screw T is
turned clockwise this gives a higher idling speed; counter-
clockwise a lower idling speed.
Basic setting and running in
The carburetor is set to its basic setting when test run at the
factory. Fine adjustment should be carried out by a skilled
technician.
NOTE! If the disk rotates while idling the T screw should be
adjusted counter-clockwise until it stops.
Recommended idling speed: 2 500 rpm.
!
Contact your servicing dealer, if the idle speed
setting cannot be adjusted so that the disk
stops. Do not use the engine until it has been
properly adjusted or repaired.
MAINTENANCE
H
T
L
Conditions
• Before any adjustments are made the air filters should be
clean and the cylinder cowling fitted. Adjusting the carburetor
while a dirty air filter is in use will result in a leaner mixture
when the filter is finally cleaned. This can give rise to serious
engine damage.
• Carefully turn the L and H needle to the mid point.
• Do not attempt to adjust the needles beyond the stops as
damage can occur.
• Now start the engine according to the starting instructions
and run it warm for 10 minutes.
NOTE! If the blade rotates the T screw should be turned
counter-clockwise until the disk stops.
• Place the engine on a flat surface so that the disk points
away from you and so that the disk do not come into contact
with the surface or other objects.
Low speed needle L
Turn the low speed needle L clockwise until the stop. If the
engine has bad acceleration or erratic idling, turn the L needle
counter-clockwise until good idling and acceleration.
NOTE! If the disk rotates in the idling position, turn the
idling speed screw counter-clockwise until the disk stops.
Final setting of the idling speed T
Adjust the idling speed with the screw T. If it is necessary to re-
adjust, first turn the idle speed adjusting screw T clockwise, until
the disk starts to rotate. Then turn, counter-clockwise until the
disk stops. A correctly adjusted idle speed setting occurs when
the engine runs smoothly in every position. It should also be
good margin to the rpm when the disk starts to rotate.
!
Contact your servicing dealer, if the idle speed
setting cannot be adjusted so that the blade
stops. Do not use the engine until it has been
properly adjusted or repaired.
Correctly adjusted carburetor
A correctly adjusted carburetor means that the engine
accelerates without hesitation. Furthermore, the disk must not
rotate at idling. A too lean adjusted low speed needle L may
cause starting difficulties and bad acceleration. A too lean
adjusted high speed needle H gives lower power=less capacity,
bad acceleration and/or damage to the engine. A too rich
adjustment of the two speed needles L and H gives accelera-
tion problems or too low working speed.
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