MAINTENANCE
Fine adjustment of the idle speed TCorrectly adjusted carburettor
Adjust the idle speed with the idle adjustment screw T, if When the carburettor is correctly adjusted the machine
adjustment is necessary. First turn the idle adjustment screw accelerates without hesitation and burbles a little at maximum
T clockwise until the blades start to move. Then turn the idle speed. It is also important that the blades do not move when
adjustment screw T anticlockwise until the blades stop. The the engine is idling or when the choke control is in the start
idle speed is correctly adjusted when the engine runs position. If the low speed jet L is set too lean it may cause
smoothly in every position. There should also be a clear starting difŢculties and poor acceleration.
margin to the speed at which the blades start to move. The If the high speed jet H is set too lean it will result in less power,
blades must also remain stationary when the choke control is
in the start throttle position.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.
Muf�er
CAUTION! Some muf�ers are Ţtted with a catalytic
converter. See chapter on Technical data to see whether your
machine is Ţtted with a catalytic converter.
IMPORTANT! If the idle speed cannot be adjusted so that the The muf�er is designed to reduce the noise level and to direct
cutting attachment stops, contact your dealer/service the exhaust gases away from the operator. The exhaust
workshop. Do not use the machine until it has been correctly
adjusted or repaired.gases are hot and can contain sparks, which may cause Ţre
if directed against dry and combustible material.
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.
Some muf�ers are equipped with a special spark arrestor
mesh. If your machine has this type of muf�er, you should
clean the mesh at least once a week. This is best done with a
wire brush.
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.
On muf�ers without a catalytic converter the mesh should be
Note that the engine should not be under load when you cleaned weekly, or replaced if necessary. On muf�ers Ţtted
adjust the high speed jet H. The high speed jet H is adjusted with a catalytic converter the mesh should be checked, and if
correctly when the machine burbles a little. If the machine necessary cleaned, monthly. If the mesh is damaged it
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.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 muf�er. A
blocked mesh will cause the machine to overheat and result
in damage to the cylinder and piston. See also instructions
under the heading Maintenance.
CAUTION! Never use a machine with a defective muf�er.
H
WARNING! Muf�ers Ţtted with catalytic
CAUTION! For optimum adjustment of the carburettor, converters get very hot during use and
contact a qualiŢed dealer/service workshop that has a !remain so for some time after stopping. This
revolution counter at their disposal. also applies at idle speed. Contact can result
in burns to the skin. Remember the risk of
Å¢re!
16 � English |
ACEC
