I've got two 1979 ATC110's with the points motors and one 1984 ATC110 with the CDI motor. If I ride these machines in the rain, or snow or get them wet at all - both of the 1979's will shock you if you touch anything metal. Obviously the source is the spark plug wire, but why it travels through anything metal on the frame is beyond me. It gets worse, the wetter the machine gets. And in some cases, if you bomb through a puddle, it misfires and dies out and needs a minute or so to recover (and it's not sucking water in the airbox)
You can feel it through gloves, through the metal throttle housing and handbars as a mild buzzing as you ride. If you touch the plastic spark plug boot with a glove on as it idles, you get shocked bad enough that you can hold onto your buddy with your free arm and shock him
I thought it was just an issue with one of the 1979's, but I noticed it with the other machine as we were riding in the rain. Both of them have hard plastic spark plug boots that aren't very well insulated at all, could this be the culprit? I haven't seen any obvious problems with torn wiring or exposed wires touching anything out of the ordinary. And otherwise they are both in really good condition.
Any tips would be appreciated. Oh, and the 1984 runs fine when wet.