Testing Wiring; Testing Wiring Harness; Without M-Tronic - Stihl MS 661 Manual

: Check the key (1) and replace if
necessary.
: Check that key (1) is properly
seated, readjust if necessary.
Crankshaft/flywheel joint must be
free from grease and oil.
MS 661, MS 661 C-M
1
If slot (arrow) is worn, install a new
flywheel.
Make sure the key engages the slot
(arrow) in the flywheel.
– Set air gap between ignition
module and flywheel, b 7.3
– Reassemble all other parts in the
reverse sequence.
7.8

Testing Wiring Harness

The following test distinguishes
between the standard machine
version (without M-Tronic) and
machine versions with M-Tronic /
handle heating or with M-Tronic /
handle and carburetor heating.
7.8.1 Testing Wiring Harness

without M-Tronic

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.
– Remove the rewind starter,
b 9.2
2 3
: Pull the short circuit wire (1) out
of the guide (arrow) and
disconnect the terminal (2).
: Connect the ohmmeter to
ground (3) and the short circuit
wire (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 7.8.1
– Set the Master Control lever to
"F".
The resistance measured must be
infinitely high. If not, replace the
wiring harness, b 7.8.1
Perform the contact and continuity
test on the ground wire too.
If the ground wire is damaged, the
wiring harness must be replaced.
– If no fault can be found, check the
ignition system with the aid of the
troubleshooting chart, b 7.13
1
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