I recently got a stock 1975 XS650 B. It's in pretty good shape; it's not a basketcase. Brand new AGM battery, cleaned carbs.
The other night, the bike died on me in the middle of traffic. The start button did nothing at all. I parked it and took the subway home. The next day I thoroughly cleaned the kill switch contacts and put in a brand new fuse just in case (this bike only has 1 fuse). I made sure the kill switch contacts were nice and shiny. Voila, the bike started, so I rode it home. I *almost* made it home...
The bike died again a few blocks away from my home. I tried kickstarting it, no good. The start button did nothing. I gave up, left and came back an hour later. I cleaned the start button contacts, very thorough. It worked, the bike started right up. I managed to get home before it died. It won't restart. Kicking has no effect, and the start button makes no sound at all. The headlight is fine, the start button doesn't even dim the headlight.
So I yanked out the left voltage regulator and the relay on the right. I cleaned the contacts on them that evening. The next day, I put them back. Press the start button, the bike starts! Ran nice and strong, without a hitch. So I let it idle a good 5 mins and then take off. My smile ended about 3 minutes later, because the bike spontaneously dies about a quarter mile up the avenue. No sputter, just suddenly shuts off, and I coast to a stop. The same symptom--headlight is fine, but no effect from the start button or kick. I walked home.
Does anyone know what's going on? I am 95% sure it's electrical but I don't know where to look. Thanks
The other night, the bike died on me in the middle of traffic. The start button did nothing at all. I parked it and took the subway home. The next day I thoroughly cleaned the kill switch contacts and put in a brand new fuse just in case (this bike only has 1 fuse). I made sure the kill switch contacts were nice and shiny. Voila, the bike started, so I rode it home. I *almost* made it home...
The bike died again a few blocks away from my home. I tried kickstarting it, no good. The start button did nothing. I gave up, left and came back an hour later. I cleaned the start button contacts, very thorough. It worked, the bike started right up. I managed to get home before it died. It won't restart. Kicking has no effect, and the start button makes no sound at all. The headlight is fine, the start button doesn't even dim the headlight.
So I yanked out the left voltage regulator and the relay on the right. I cleaned the contacts on them that evening. The next day, I put them back. Press the start button, the bike starts! Ran nice and strong, without a hitch. So I let it idle a good 5 mins and then take off. My smile ended about 3 minutes later, because the bike spontaneously dies about a quarter mile up the avenue. No sputter, just suddenly shuts off, and I coast to a stop. The same symptom--headlight is fine, but no effect from the start button or kick. I walked home.
Does anyone know what's going on? I am 95% sure it's electrical but I don't know where to look. Thanks