Charging gone wrong

[Bobber 12]

I have a 1980 yamaha bobber that I unfortunaly wired myself. everything works great it has a head light, tail light, and a charging system and ignition. my problem is when I charge the battery with my battery tender the bike starts up just fine 12.5 volts at the battery. when I run it more than 20 miles the bike loses volts to the point that I have to kick start it. I ran it for another 15 miles and never lost power just not enough juice to run the electric start. Got back home and the battery was sitting at 11.5volts. my question is Ive checked my brushes "good". Checked the Alternator Ohm ed out good. Now what is next?

 

[pckopp]

I just went through something very similar. My bike would run about 10 to 15 minutes and then the battery was dead. I had a bad regulator. I don't know any way to specifically test just the regulator, but I unplugged mine and the bike started acting normally, although just not charging the battery.

I put a voltmeter on the battery and connected and disconnected the regulator. When it was connected, the battery voltage dropped rapidly. When I unplugged it, the battery recovered. The tests on the field coil and stator windings and diodes all checked good, so I decided the regulator was bad. New one on order.

Good luck. Maybe someone here knows specific tests for the regulator.

 

[barkcollar]

my reg was not grounded good. all better now.
Phil,whats up SC homie.

 

[pckopp]

Phil,whats up SC homie.

Off to the car wash today, degreasing the XS650. And enjoying the cooler weather.

 

[bloodthirstysystem]

regulator test -

3. On the solid state regulator models all you need to do is locate the green wire at the regulator plug and make a jump from it to ground. That bypasses the regulator and allows full battery current to flow through the brushes out of the rotor through the green wire to ground. That causes the rotor to make a stronger magnetic field which in turn causes more current to flow in the stator. If your battery terminal charge voltage jumps up to 14.5VDC when you rev the engine then the regulator or the ground connection for the regulator is your problem.

http://xs650temp.proboards.com/index.cgi?board=Charging&action=display&thread=3461

 

[Ironsled77]

What blood said........plus use the link. It is the best out there that I know of. All my stuff was bad. Just did the rotor and stator. R/r will be here today!

 

[barkcollar]

My rotor/stator had a partial ground caused by carbon dust build-up. My brush wires also were grounding out..

Phil. Lovin the weather.