Husqvarna 343F Manuel D'utilisation page 65

Fine adjustment of the idle speed T
Adjust the idle speed using the idle adjustment screw T, if it is
necessary to readjust. First turn the idle adjustment screw T
clockwise until the cutting attachment starts to rotate. Then turn
the screw anticlockwise until the cutting attachment stops. The
idle speed is correctly adjusted when the engine will run
smoothly in every position. The idle speed should also be well
below the speed at which the cutting attachment starts to
rotate.
WARNING! If the idle speed cannot be
!
adjusted so that the cutting attachment
stops, contact your dealer/service
workshop. Do not use the machine until it
has been correctly adjusted or repaired.
High speed jet H
The high speed jet H affects the engine power, speed,
temperature and fuel consumption. If the high speed jet H is set
too lean (screwed in too far) the engine speed will be too high
and cause engine damage. Do not let the engine run at full
speed for more than 10 seconds.
Setting procedure without a load (Blade can be used)
The machine is equipped with speed control in the ignition
system. It is extremely important to be aware of this when
adjusting the carburettor.
343R, 345RX: Speed control at: 12500 rpm
343F, 343FR, 343FRM, 345FX, 345FXT: Speed control at:
13500 rpm
When attempting to adjust the speed over that specified, the
speed is not changed, but only causes the engine to receive too
little fuel resulting in a large risk of engine failure.
Run the machine warm for approximately 5 minutes alternating
between short intervals of full throttle and idling. When the
carburettor is to be adjusted, apply full throttle and turn the H-
needle anti-clockwise until the engine speed reaches 10,500-
11,000 r/min (burbles) or until the cap reaches its stop position.
Now turn the H-needle slowly clockwise until the engine
reaches the speed when the speed control comes into force. In
some cases, speed control can come into force at 200-300 revs
below or above that specified. It is important that you do not
continue to turn the H-needle clockwise when the engine speed
has stabilised. Screw the H-needle (anti-clockwise) a few
tenths of a turn instead.
MAINTENANCE
H
Setting procedure with a load (Trimmer head should be
used)
Ensure the length of the trimmer cord is correct, i.e. exactly
reaches the knife on the trimmer guard. Use either 3 mm or 3.3
mm diameter trimmer cord.
Run the machine warm for about 5 minutes mostly at full
throttle. When the carburettor is to be adjusted, apply full
throttle and turn the H-needle anti-clockwise until the engine
burbles or until the cap reaches its stop position. (If the engine
runs smoothly when the cap is in its stop position no further
adjustment is necessary!) Turn the H-needle slowly clockwise
until the engine runs absolutely smoothly. (Burbling has
stopped completely). Now screw the H-needle (anti-clockwise)
a few tenths of a turn.
CAUTION! For optimum adjustment of the carburettor, contact
a qualified dealer/service workshop that has a revolution
counter at their disposal.
Correctly adjusted carburetor
When the carburetor is correctly adjusted the machine will
accelerate without hesitation and burble a little at maximum
speed. It is also important that the cutting attachment does not
rotate at idle. If the low speed jet L is set too lean it may cause
starting difficulties and poor acceleration. If the high speed jet
H is set too lean it will result in less power, less performance,
poor acceleration and/or damage to the engine. If both the L
and H jets are set too rich it will results in acceleration problems
or too low a working speed.
Adjusting the start throttle speed (343FR,
343FRM, 343R, 345RX)
The correct start throttle speed is set by means of an adjuster
on the rear of the handle next to the cable. Use this screw (5
mm Allen screw) to increase or decrease the start throttle
speed.
5 mm
Proceed as follows:
1 Run the machine at idle.
2 Press the start throttle lock as described under the
heading Starting and stopping.
3 If the start throttle speed is too low (below 4000 rpm),
turn the adjuster screw A clockwise until the cutting
attachment starts to rotate. Then turn A clockwise a
further 1/2 turn.
4 If the start throttle speed is too high, turn the adjuster screw
A anticlockwise until the cutting attachment stops. Then
turn adjuster screw A clockwise a further 1/2 turn.
H
English
–
65