Operation Manual

8
English / USA
BR 420
Muffler and Catalytic Converter
!Warning!
The muffler and other parts of the engine
(e.g. fins of the cylinder, spark plug)
become hot during operation and remain
hot for a while after stopping the engine.
To reduce risk of burns do not touch the
muffler and other parts while they are
hot.
!Warning!
To reduce the risk of fire or burn injury,
let the unit cool down before refueling
your power tool after use.
!Warning!
Never disassemble or modify your
muffler. The muffler could be damaged
and cause an increase in heat radiation
or sparks, thereby increasing the risk
of fire or burn injury. You may also
permanently damage the engine. Have
your muffler serviced and repaired by
your STIHL servicing dealer only.
!Warning!
To reduce the risk of fire or burn injury,
keep the area around the muffler clean.
Remove all debris such as pine needles,
branches or leaves.
!Warning!
Some STIHL blower
models are equipped with
a catalytic converter,
which is designed to
reduce the exhaust
emissions of the engine
by a chemical process in the muffler.
Due to this process, the muffler does not
cool down as rapidly as conventional
mufflers when the engine returns to idle
or is shut off. To reduce the risk of fire
and burn injuries, the following specific
safety precautions must be observed.
!Warning!
Since a muffler with a catalytic converter
cools down less rapidly than
conventional mufflers, always set your
backpack blower down in the upright
position and never locate it where the
muffler is near dry brush, grass, wood
chips or other combustible materials
while it is still hot.
Let the engine cool down sitting on
concrete, metal, bare ground or solid
wood (e.g. the trunk of a felled tree)
away from any combustible substances.
!Warning!
An improperly mounted or damaged
cylinder housing or a damaged/
deformed muffler shell may interfere
with the cooling effect of the catalytic
converter. To reduce the risk of fire or
burn injury, do not continue work with a
damaged or improperly mounted
cylinder housing or a damaged/
deformed muffler shell. Your muffler is
furnished with a screen designed to
reduce the risk of fire from the emission
of hot particles. Due to the heat from the
catalytic reaction, this screen on a
catalytic converter will normally stay
clean and need no service or
maintenance. If you experience loss of
performance and you suspect a clogged
screen, have your muffler maintained by
a STIHL servicing dealer.