Spark Test - Stihl MS 661 Manual

: Connect the MDG 1 between the
spark plug and spark plug boot
– ground clamps must engage
hexagon on spark plug.
– To run diagnosis on MS 661,
select "Other STIHL Products".
Then start the diagnosis function
and follow the steps in the
diagnosis software.
To obtain an accurate result, pull
the starter rope briskly.
The engine may start and
accelerate during the test.
Exercise extreme caution when
troubleshooting and carrying out
maintenance or repair work on the
ignition system. The high voltages
which occur can cause serious or
fatal accidents.
Troubleshooting on the ignition
system should always begin at the
spark plug, b 3.5
– Remove the rewind starter,
b 9.2
42
7.5

Spark Test

Using ZAT 4 ignition system
5910 850 4503
1 2
– Before starting the test, install a
new spark plug in the cylinder
and tighten it down firmly.
: Connect spark plug boot to the
input terminal (1). Push the
tester's output terminal (3) on to
the spark plug.
High voltage – risk of electric shock.
– Crank the engine quickly with the
rewind starter and check spark in
the tester's window (2).
The engine may start and
accelerate during the test.
If a spark is visible, the ignition
system is in order.
– If no spark is visible in the
window (2), check the ignition
system / M-Tronic with the aid of
the troubleshooting chart,
b 7.13, b 8.7
Using the ZAT 3 ignition tester
5910 850 4520
1
– Before starting the test, install a
3
new spark plug in the cylinder
and tighten it down firmly.
: Connect spark plug boot to the
terminal (2).
: Attach the ground terminal (1) to
the spark plug.
: Use adjusting knob (4) to set the
spark gap to about 2 mm, see
spark window (3).
MS 661, MS 661 C-M
3 4
2