Operating Instructions; Cleaning The Air Filter - Stihl BR 420 Manual De Instrucciones

Operating Instructions

During break-in period
A factory new machine should not be run
at high revs (full throttle off load) for the
first three tank fillings. This avoids
unnecessary high loads during the
break-in period. As all moving parts
have to bed in during the break-in
period, the frictional resistances in the
engine are greater during this period.
The engine develops its maximum
power after about 5 to 15 tank fillings.
During operation
After a long period of full-throttle
operation, allow engine to run for a while
at idle speed so that the heat in the
engine can be dissipated by flow of
cooling air. This protects engine-
mounted components (ignition,
carburetor) from thermal overload.
After finishing work
Wait for engine to cool down. Drain the
fuel tank. Store the machine in a dry
place. Check tightness of nuts and
screws (not adjusting screws) at regular
intervals and retighten as necessary.
BR 420

Cleaning the Air Filter

1
2
1
Dirty air filters reduce engine power
increase fuel consumption and make
starting more difficult.
If there is a noticeable loss of engine
power
Turn choke knob to g
:
: Release the screws (1) and pull
off the filter cover (2).
English / USA
3
4
: Remove the main filter (3) from the
cover and inspect it –
if it is dirty or damaged, fit a new
one.
: Always install a new prefilter when
you change the main filter.
: Take the prefilter (4) out of the filter
cover.
: If the prefilter is wet, dry it – then
knock it out on the palm of your
hand or blow out with compressed
air.
: Always replace a damaged prefilter.
5
19