High speed jet h, Correctly adjusted carburettor, Muffler – English Leather 245R/RX User Manual
Page 29: Cooling system, Maintenance
English
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MAINTENANCE
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.
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.
Cooling system
To keep the working temperature as low as possible the
machine is equipped with a cooling system.
The cooling system consists of:
1
Air intake on the starter.
2
Fins on the flywheel.
3
Cooling fins on the cylinder.
4
Cylinder cover (directs cold air over the cylinder).
Clean the cooling system with a brush once a week, more
often in demanding conditions. A dirty or blocked cooling
system results in the machine overheating which causes
damage to the piston and cylinder.
!
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.
H
!
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!
250R/252RX
240R/245R/245RX
265RX