I've had them on dirt bikes over the years and no issues, but I have no idea about Harleys. I rolled with Magnum cables and lines on my scoot. Good luck!
"JUNK" I wouldn't put MP on a bicycle. I've had two sets that came with my bars and both sets were crap. I went with Magnum Chromlite, the're great. The plastic coating turn yellow on the MP in just a short while, and the clutch cable start sticking after about 15,000 miles. And yes I've lubed them with grafite, that just turns them black for a couple of inches.