The carburettor has 3 adjusting screws:
Idling end-stop screw "T"
Low speed mixture screw "L"
High speed mixture screw "H"
Only qualified mechanics must adjust the
regulating screws for idle mixture "L" and
full load mixture "H".
Turn the idling end-stop screw "T" to adjust the
idling speed in accordance with the details provided
in the specification. Use an engine rev counter for
this job.
If the idling speed is too high, turn the idling
end-stop screw "T" anti-clockwise.
If the idling speed is too low (engine stops) turn
the idling end-stop screw "T" clockwise until the
engine runs smoothly.
With the throttle set to idle, the cutting tool
must not, under any circumstances, rotate!
If the idling speed cannot be set correctly with the
idling end-stop screw "T", request an authorised
service centre to tune the carburettor.
The following instructions are for authorised
service shops
D-CUT carburettors:
Use the D-CUT carburettor key to adjust the idle
mixture screw "L" and the full load mixture screw
"H".
Carburettors with limiter caps:
The regulating screws for idle mixture and full load
mixture can only be adjusted in a limited range.
Clean the air filter before adjusting the low speed
screw!
Let the engine run warm before adjusting the
engine speed.
The carburettor is tuned for optimum engine
performance. Use a rev counter to tune the
carburettor correctly!
Do not adjust the engine to a higher speed.
Excessive engine speed can lead to major engine
damage!
9.5 Air Filter Maintenance
Contaminated air filters cause a reduction in engine
performance and increase fuel consumption with
more pollutants in the exhaust gas. Engines are less
likely to start readily with a contaminated air filter.
Carry out the following maintenance jobs regularly.
Operating and maintenance instructions
Fig. 20
Before opening the air filter, close the choke
prevent dirt entering the carburettor.
Turn the wing screw (31) at the air filter cover
(11) anti-clockwise.
Flip the top of the air filter cover forward and
remove.
Remove the fabric air filter (32).
Clean the area around the filter.
When using the equipment all day, clean the fabric
air filter daily. Under extremely dusty conditions,
clean the filter several times during the day as well.
Simply tapping the filter is the best cleaning
method.
Never wash or clean the air filter with
compressed air or by wetting it; never place in
an oil bath or into cleaning solution.
The air filter is blocked, if the engine speed
noticeably drops when the carburettor is correctly
adjusted. Under these circumstances, the filter needs
replacing (part no. 20 48 154).
Low engine speed due to a blocked air filter must
never be compensated by incorrect carburettor
adjustments. This would cause the engine to
overload, resulting in severe engine failure.
Engine failure caused by incorrect care is excluded
from our warranty.
Insert the new or cleaned fabric air filter into the
casing.
Position the air filter lid with the lower guiding
pins onto the housing and push into place.
Secure the filter cover by turning the wing screw
(31) clockwise.
to
ENGLISH
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