# Sparking / Arcing along the spark plug.



## Calvy (Jun 21, 2008)

I have a Homelite, Z825sba String Trimmer, Model # UT-15133. Bought new in 1999. 

Need your expert assistance. After 12 - 13 years of service, the unit still runs. I noticed this past weekend, that when the engine is idling it starts to spit (engine misfire) a little. When the engine spit I heard an arcing sound coming from the engine. I looked and listen closer and noticed sparking/arcing along the spark plug. The spark/arc appears to be coming from spark plug wire rubber cap down the spark plug to the engine cylinder head. The spitting of the engine and the spark/arc appear to be in direct correlation of each other. The spark plug is tight and the spark plug wire rubber cap is on securely. What could be causing the spark/arching? Is this normal and should I be concerned?  

History, I did replace the coil (Ignition Module) in the unit approximately 2 - 3 years ago. Never noticed the sparking/ arcing or sound before, not to stay that it wasn't there. Any suggestions?


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## 30yearTech (Sep 14, 2006)

Probably just need to replace the spark plug boot. When they get old they can sometimes conduct voltage and cause issues just as you describe.


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