Ignition System; Checking The Ignition Spark - Husqvarna 545RXT AT Workshop Manual

CAUTION: The engine has an electronic
ignition system without moving parts. A
faulty component cannot be repaired and
must be replaced.

8.1 Checking the ignition spark

8.1.1 Checking the spark plug
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.
1. Remove the cylinder cover.
2. Remove the spark plug and clean it from soot
deposits with a steel brush.
3. Measure the electrode gap. It should be 0.5 mm.
See figure 1.
4. Adjust the gap as needed to the correct value with
the side electrode.
5. If the electrodes are worn more than 50%, replace
the spark plug. A gap larger then 0,5 mm puts a lot of
stress on the ignition module and can cause short-
circuiting. See figure 2.
6. Ground the spark plug by holding it against the
cylinder. See figure 3.
7. Pull the starter handle sharply.
8. If no spark is seen between the electrodes use a test
spark plug (See pos. 2 in Service tools)
9. If a spark is seen when you use the test spark plug,
replace the defective spark plug. If no spark is seen
continue to next chapter.
10. Attach the cylinder cover.
NOTE! For a more detailed control of the spark
quality, use the ignition tester as described
in appendix I.

8 Ignition system

Fig. 1
Fig. 2
Fig. 3
Ignition system and heated handles
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