Motorcycle Repair: TX650 -No power, battery terminals, hygrometer

Question
Hi Chris,
I have a 1973 yamaha tx650 that loses all electrical power. I thought it may have damaged wire somewhere but could it be the coils or some other component.
1. turn the key.. nothing
2. kick it over holding plug.. nothing
3. leave the key turned on and come back an hour later and lights are on and has power!
4. start it and it dies after a couple of seconds.. No power.

thanks Mark

Answer
Hi Mark.
 As old as the bike is, it could be a lot of different things.

1)  Start with the battery.  Check it with a meter and a hygrometer.  If the hygrometer shows one or more bad cells, then replace it.

2)  Check the wiring for shorts, grounds, bad connections, bad fuses and bad fuse connections.

3)  Check (with a meter) all switches, starter components and ignition components.  For the complex components (coils and other such parts) match what you find against the specs in the manual.

4)  Once it is running, check the power output at the battery terminals.  It should read between 13-15 VDC.

Start there and let me know what you find.
Good luck.
FALCON