Electrical System; Checking The Ignition Spark - Husqvarna 129C Workshop Manual

Repair Instructions
The engine is equipped with an electronic ignition system completely without moving parts. Consequently,
a faulty component cannot be repaired, but must be replaced by a new component.
The spark in an electronic ignition system has a very short burn time and can therefore be interpreted as
weak and can be difficult to see while troubleshooting.

7.8 Checking the ignition spark

1
Remove the spark plug and clean it from soot
deposits with the help of a steel brush.
Check the electrode gap. It should be 0.5 mm. Use
the feeler gauge no. 502 51 91-01.
Adjust the gap as needed to the correct value with
the side electrode.
2
If the electrodes are worn more than 50% the
spark plug should be changed.
Too large a spark gap entails a great deal of stress
on the ignition module and risk for short-circuiting.
3
Check if a spark occurs when attempting to start.
Earth the spark plug by attaching it to the starter
screw with a steel wire as shown in figure 22. Give
a sharp pull on the starter handle.
A spark should be seen between the electrodes.
If no spark is seen test with test spark plug no.
502 71 13-01.
If a spark then occurs, the spark plug is broken.
Try a new spark plug.
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- English

Electrical system

Fig 20
Fig 21
Fig 22