Husqvarna 123C User Manual

English

 – 19

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.

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. 

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.

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.

H