20 Series 4144 Components FC, FS, KM
5.9 Short Circuit Wire
5.9.1 Testing
If the spark plug, ignition lead and 
spark plug boot are in order, check 
the short circuit wire.
– Remove the shroud, b 5.1
: Disconnect the short circuit wire 
(1).
– Connect the ohmmeter to ground 
(arrow) and the short circuit wire 
(1).
– Set the stop switch to "
0" and 
hold it in that position.
The resistance measured must be 
about 0 Ω. If it is much higher, the 
reason may be the stop switch or 
the wire. Damaged parts must be 
replaced, b 5.9.2, b 5.9.3.
– Release the stop switch.
The resistance measured must be 
infinitely high. If not, fit a new short 
circuit wire or stop switch, b 5.9.2, 
b 5.9.3.
545RA057 TG
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To locate the fault, test the wires for 
continuity and check insulation for 
damage. If the wires are in order, 
check operation of stop switch, 
b 5.10
If no fault can be found, check the 
ignition system with the aid of the 
troubleshooting chart, b 5.10.
– Check ground wire for continuity.
– Reassemble in the reverse 
sequence.
5.9.2 Removing and Installing 
(Loop Handle Version)
Separate short circuit (black) and 
ground (blue) wires are installed in 
these machines and may be 
replaced individually in case of 
damage.
– Remove the drive tube, b 9.1
– Remove the shroud, b 5.1
: Pull boot (1) off the spark plug.
545RA008 TG
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: Disconnect the short circuit wire 
(1) and ground wire (2).
– Pull the short circuit wire out of 
the guide (arrow).
– Press down the interlock lever to 
disengage it from the throttle 
trigger.
: Pull out the support (1).
:  Take the short circuit wire (1) 
and ground wire (2) out of the 
guide (arrow).
545RA058 TG
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545RA059 TG545RA060 TG
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