Muffler - Husqvarna 343F Operator's Manual

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.
Apply full throttle and turn the high speed jet H very slowly
clockwise until the engine slows down. Then turn the high
speed jet H very slowly anticlockwise until the engine starts to
run unevenly. Now turn the high speed jet H slowly clockwise
a little way until the engine runs smoothly.
Note that the engine should not be under load when you
adjust the high speed jet H. You should therefore remove the
cutting attachment, nut, support flange and drive disc before
adjusting the high speed jet H.
The high speed jet H is adjusted correctly when the machine
burbles a little. If the machine races then the setting is too
lean. If the engine produces a lot of smoke and burbles a lot
then the setting is too rich.
CAUTION! For optimum adjustment of the carburettor,
contact a qualified dealer/service workshop that has a
revolution counter at their disposal.
Correctly adjusted carburettor
When the carburettor 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
(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.
MAINTENANCE
H
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.
Muffler
CAUTION! Some mufflers are fitted with a catalytic converter.
See chapter on Technical data to see whether your machine
is fitted with a catalytic converter.
The muffler is designed to reduce the noise level and to direct
the exhaust gases away from the operator. The exhaust
gases are hot and can contain sparks, which may cause fire
if directed against dry and combustible material.
Some mufflers are equipped with a special spark arrestor
mesh. If your machine has this type of muffler, you should
clean the mesh at least once a week. This is best done with a
wire brush.
On mufflers without a catalytic converter the mesh should be
cleaned weekly, or replaced if necessary. On mufflers fitted
with a catalytic converter the mesh should be checked, and if
necessary cleaned, monthly. If the mesh is damaged it
should be replaced.
If the mesh is frequently blocked, this can be a sign that the
performance of the catalytic converter is impaired. Contact
your dealer to inspect the muffler. A blocked mesh will cause
the machine to overheat and result in damage to the cylinder
and piston.
CAUTION! Never use a machine with a defective muffler.
WARNING! Mufflers fitted with catalytic
!
converters get very hot during use and
remain so for some time after stopping. This
also applies at idle speed. Contact can result
in burns to the skin. Remember the risk of
fire!
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English