arching

Whilst servicing my bike I noticed my rough Idle when hot may be due to one of my front ht plugs arching. It seems to be arching straight through the side of the rubber plug/cap. Is there a cheap and easy solution to this? If I buy new cable can I use the existing plugs/caps and screw...

Got a bit of a problem...I have a 2003 Max 2500 miles on the clock and a real minter. Suffering the hot engine idle problem. Did a bit of research and was convinced it was the ususl HT caps leaking current. This was confirmed when returning from a ride I let the engine tickover and lo and be...