Operation Manual

69MS 241 C
8. M-Tronic
The fully electronic M-Tronic engine
management system controls the
ignition timing and fuel flow, taking
all external conditions into account.
A basic or standard setting of the
carburetor is no longer required.
The M-Tronic electronically adjusts
the fuel-air mixture in the carburetor.
The M-Tronic controls all operating
states such as start, idle, part
throttle and full throttle while
accounting for the external
conditions, e.g., use at varying
attitudes, as well as changing
temperatures or fuel quality – the
carburetor does not have any
adjusting screws.
Troubleshooting and test
procedures are described in the
following chapters, Testing, b 8.2,
Troubleshooting, b 8.5.
2410RA546 TG
8.1 Calibrating the control
unit
If the outstanding running behavior
and usual performance or maximum
speed of the engine can no longer
be attained, the usual engine
performance can be attained again
by calibrating the control unit.
A regulating cycle only starts if the
machine is operated for
approximately 2 seconds under
constant conditions.
If the maximum speed is not
reached...
– Examine air filter, clean or
replace if necessary, b 13.1
– Examine the spark arresting
screen (if installed); clean or
replace it if necessary, b 6.1
– Check chain tension, adjust if
necessary
– Check chain lubrication
– Set Master Control lever to
Start }
– Start engine and let it warm up
– Carry out five uniform cuts to
length
– speed between 8000 rpm and
11200 rpm, log diameter
approx. 30 cm
– If the outstanding running
behavior and the usual
performance are not attained,
continue troubleshooting and test
procedures as described under
Testing, b 8.2,
Troubleshooting, b 8.5
If the control unit or carburetor is
replaced during servicing...
– Remove the saw chain and guide
bar
– Reinstall the chain sprocket
cover
– Set Master Control lever to
Start }
– Start machine – do not blip the
throttle trigger
After completion of the following
procedure, the Master Control lever
must be moved from Start } to
STOP 0 without pressing the throttle
trigger.
– Let the machine warm up for at
least 60 seconds in the Start }
position and then move the
Master Control lever to STOP 0
– Calibration is completed
The control unit is adjusted to the
carburetor while the engine runs in
the position Start }.
The machine must be switched off
immediately for the information to
be stored in the control unit.