Stihl MS 650

50 MS 650, MS 660
: Slide the setting gauge (1)
1111 890 6400 between the
arms of the ignition module and
the flywheel.
– Press the ignition module (2)
against the setting gauge.
178RA061
VA
2 3
1
3
: Tighten down the screws (3)
firmly – b 3.5
– Remove the setting gauge and
use a feeler gauge to check the
air gap. It should be 0.2 mm.
– Install the fan housing with
rewind starter – b 8.2
– Fit the shroud – b 6.2
To test the ignition module, use
either the ZAT 4 ignition system
tester 5910 850 4503 or the ZAT 3
ignition system tester
5910 850 4520.
The ignition test refers only to a
spark test, not to ignition timing.
Using the ZAT 4 ignition tester
5910 850 4503
– Before starting the test, install a
new spark plug in the cylinder
and tighten it down firmly –
b 3.5
VA
212RA209
3
21
: Remove spark plug boot and
connect it to the input
terminal (1).
: Push the tester’s output
terminal (3) onto the spark plug.
– Set the Master Control lever
to “#“
: Crank the engine quickly with the
rewind starter (min. 1,000 rpm)
and check spark in the tester’s
window (2).
Warning!
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 with the aid of the
troubleshooting chart – b 7.6
Using the ZAT 3 ignition tester
5910 850 4520
– Before starting the test, install a
new spark plug in the cylinder
and tighten it down firmly –
b 3.5
VA
208RA054
ZAT 3
5910 850 4520
3
2
1
: Remove spark plug boot and
connect it to terminal (2).
: Attach ground terminal (1) to the
spark plug.
: Use adjusting knob (3) to set
spark gap to about 2 mm.
7.2.2 Testing the Ignition
Module