I remember back in the early 80's the alternator going on my Kawasaki KH triple on my way through the new forest at night. I was heading down to Lymington for an early start on a yacht race, so was keen to get there. It was a moonlit night and without the lights the engine ran fine, so I rode down there lights off, only switching them on when another vehicle hove into view (at which point the engine would splutter & start dying). I got there ok.