The selenium rectifier used to fail regularly on my '49, but that might have been because I used the ones intended for use in a TV. The lights used a bit more current than the dynamo produced so they were at about half intensity after a couple of hours with the battery holding at about 3 volts. It had a Bosch magneto, so ignition was never a problem.

Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python