Could very well be a burned cap. It can also be a burned rotor. I had mine do that. You willneed to get a cap and rotor for a Unilite, standard parts do not fit. Any mallory dealer can get them for you.
One more thing. From my own experience, if you have the one without the vacuum advance, give it a little more advance on the base timing. I found that mine was much happier with 15 degrees advance over the stock setting.
