Stihl MS 231 Manual page 51

7.7 Short Circuit Wire
The ground and short circuit wires
are combined in a wiring harness.
If the spark plug, ignition lead and
spark plug boot are in order, check
the short circuit wire.
7.7.1 Testing
– Remove the fan housing, b 8.2
1
2
3
: Disconnect terminal (1) of the
short circuit wire (2).
: Connect the ohmmeter to
ground (3) and the short circuit
wire's terminal (1).
– Set the Master Control lever to
0
" ".
The resistance measured must be
about 0 Ω. If it is much higher, the
reason is a break and the wiring
harness has to be replaced,
b 7.7.2.
– Set the Master Control lever to
"F".
The resistance measured must be
infinitely high. If not, replace the
wiring harness,
b 7.7.2.
50
All manuals and user guides at all-guides.com
Also perform contact and continuity
check on ground wire between
terminal and contact spring and
replace the wiring harness if
necessary.
– If no fault can be found, check the
ignition system with the aid of the
troubleshooting chart, b 7.8
– Reassemble in the reverse
sequence.
7.7.2 Removing and Installing
– Remove the shroud, b 6.4
– Pull the boot off the spark plug.
– Remove the fan housing,
b 8.2
– Remove the choke rod,
b 10.3.3
1
: Pull the retainers (1) and (2)
carefully out of the slots (arrows)
and open them.
2
1
4
3
: Disconnect terminal (1) of the
short circuit wire (2).
: Take out the screw (3).
: Pull the short circuit wire (2) and
ground wire (4) out of the
guides (arrows).
– Remove the filter base, b 12.3
– Remove the contact spring,
b 7.7.4
– Pull the switch lever off the shaft
on the filter base, b 10.1
– Pull the carburetor towards the
control handle
– take care not to stretch the fuel
hose.
2
2
1
: Pull the short circuit wire (1) and
ground wire (2) out of the
guides (arrows) in the air guide
shroud.
MS 231, MS 231 C, MS 251, MS 251 C