My son and I have recently bought an 83 XS 650. It hadn´t been ridden for a year, so we had the carburetors cleaned and a new battery put in. Things seemed fine, but the battery doesn´t seem to recharge. After a couple hours of riding, the bike stalls out from lack of electricity. Our repair shop says the voltage regulator is fine, there´s no passive draw on the battery, and that the battery was faulty (they installed a new, better battery for free), but the same problem occurred--a few days of good performance, then a dead battery and a stalled-out bike. The bike´s currently back in the shop, but I think they don´t know what to do since it passes their electrical system tests. We´d appreciate any help or suggestions.