36 MS 210, MS 230, MS 250
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.
Before starting the test, check that 
the spark plug is in good condition. 
Test the ignition coil only with the 
spark plug properly installed in the 
cylinder.
: Using the ZAT 4 ignition tester 
5910 850 4503: 
Pull the boot off the spark plug 
and connect it the input 
terminal (1). Push the tester’s 
output terminal (3) onto the spark 
plug.
 
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– Pull the rewind starter and check 
the sparkover in the tester’s 
window (2).
It is necessary to use the ZAT 3 
ignition system tester 
5910 850 4520 to test the auxiliary 
spark gap.
– Before starting the test, install a 
new spark plug in the cylinder 
and tighten it down firmly – 
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ZAT 3
5910 850 4520
3
2
1
b 3.5.
: Pull the boot off the spark plug 
boot and connect it to 
terminal (2).
: Attach ground terminal (1) 
(alligator clip) to spark plug.
Use adjusting knob (3) to set spark 
gap to about 2 mm.
While using the ZAT 3, hold it only 
by the handle or position it in a safe 
place.
Warning!
High voltage – risk of electrocution.
– Crank engine with rewind starter 
(min. 1,000 rpm) and evaluate 
spark in spark window.
If a spark is visible, the ignition 
system is in order.
If no spark is visible, check the 
wiring harness and contact spring – 
b 7.4.
If the spark plug, ignition lead and 
spark plug boot are in order, use an 
ohmmeter to check the short circuit 
wire, ground wire and contact spring 
for a break.
: Pull the short circuit wire (arrow) 
off the tag on the ignition module.
– Connect ohmmeter to ground 
and the short circuit wire.
– Set Master Control lever to "0".
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The measured resistance must be 
about 0 Ohm. If the reading is much 
higher, there is a break in the wire 
and the wire or Master Control lever 
must be replaced.
– Set Master Control lever to "1".
The measured resistance must be 
infinitely high. If not, install a new 
Master Control lever.
7.3 Testing the 
Ignition Coil
7.4 Checking the 
Wiring Harness