QuestionThe bike has been stored all winter long, I'm guessing improperly. Once out for the winter the bike wouldn't start so I bought a new battery for it and it started right up. The next morning the bike wouldn't start and the battery was dead. I can't figure out the problem; the blinkers and lights have always worked well, as far as I know, so I don't think it is something in the electrical in that regard. I was thinking it might be the starter or something along those lines?
AnswerJoseph, few things will kill a battery overnight. Unless you left the key ON in PARK position.. if it has one, then assuming no other aftermarket accessories are tied into the wiring, then the regulator/rectifier diodes have failed and the power drained out through that component.
Carefully and slowly recharge the battery at less than 2 amps, then install it back into the bike. Hook up the positive cable first, then look for any signs of a spark when you connect the negative cable end. If you see arcing, then something is causing a current draw (key off) and the regulator/rectifier is the only item that are always connected to the battery w/o a fuse or switch.
http://www.cmsnl.com/yamaha-xs750d-1977_model8627/partslist/H-03.html #9
http://www.cmsnl.com/yamaha-xs750d-1977_model8627/partslist/H-02.html #26
It looks like they used two systems... one is a combination unit reg/rect and the other version is two separate components.
Bill Silver
