This can be kind of a tough one to diagnose and cure. It does seem to show up more in hot weather. I would probably start off by checking to see if the bike has registered a "code" or not. Although not hard, it is kind of a daunting task for most folks who are not mechanically inclined. If you are going to own a Harley, I think you should invest the $50.00 in a shop, service manual. But, that is just me. Good luck. Do a search on this very website where there are numerous opins on how to do this.
I had this very thing happen to me several weeks ago. In my case, there is a wiring loom that contains numerous wires, which had popped loose from it's moorings and had brushed up against the hot engine fins on the air cleaner side of the engine (about half way up-you can see it if you remove your chrome football cover). The heat had burned a hole plumb through the outside loom and was steadily working its way through all the wires inside. Bye the way, this is the very bunch of wires that plugs into a module behind the air cleaner cover. My fix was to tape up the loom and wires where it was burnt through with some good electrical tape. I then covered this with a tin foil and then put another wrap of electrical tape over this. Lastly, I made sure that the wiring loom was properly attached to the little tab, like it is supposed to be. I am fairly sure how the loom came to be where it was. A couple of weeks ago I had the bike into the local Harley shop for a bit of warranty work. I believe the technician removed the plug and pulled on the cable when he hooked the bike up to the Harley diagnostic machine. It would be an easy thing to do, but it can have dire consequences if the cable ends up resting against a hot jug (the front one). Like you, when it happened it felt like something gave loose inside, although at the time I had no idea what it was. Just something to think about.
