The low tension lead is subject to a lot of vibration. It is not all that unusual for the copper strands to break within the insulation at the connector. To the eye everything looks OK. The ignition circuit can intermittently cut in and out creating frustration and even some danger. If your engine starts cutting out and in or just stops then is OK after you check connections, a broken low tension lead should be among the suspects. It is a good idea to carry a spare in your ﬁeld repair kit.