Connecting Test Cables; Testing Screw And - Stihl MS 661 Manual

8.3.2

Connecting Test Cables

– Remove the filter base, b 13.3
1
: Pull out the grommet (1).
2 1
: Insert plug (1) of M-Tronic
diagnostic
cable 5910 840 0400 into the
socket (2), contours (arrows)
must match – the plug (1) must
snap into place.
1
The STIHL MDG 1 must be installed
between the spark plug boot and
spark plug.
62
– Pull boot off the spark plug.
: Insert plug (1) in spark plug boot
and fit socket (2) on spark plug.
– Perform test, wires and contacts,
b 8.3, test M-Tronic according
to troubleshooting chart, b 8.7
–
– After completing test, lift the lock
and disconnect cable from
diagnostic socket.
– Install the grommet.
– Reassemble all other parts in the
reverse sequence.
8.3.3 Testing Screw and Plug
Connections and Switch
Contact
– Carry out preparations, b 8.3.1
A reliable connection is required for
communications between the
control unit, switch unit and solenoid
valve. If communications between
the control unit and solenoid valve
are interrupted or faulty, the control
unit will not produce an ignition
spark.
– In the event of interference or a
missing ignition spark, first check
the screw connections, switch
contact and wiring harness
between the control unit and
2
solenoid valve.
1
Screw (1) must be tightened down
firmly.
Wires (arrows) must be firmly
seated in the terminal sockets and
the cable lug – the plug must
engage properly.
1
Generator pin and socket
connector (1) must make full
contact.
: If necessary, pull pin and socket
connector (1) out of
guide (arrow), disconnect and
check contacts, b 8.3.3
MS 661, MS 661 C-M