I switched the wires, and double checked the voltages. Now when I have it turned on (no lights) at idle I'm getting 7 volts, and when it revs it goes up to 7.5 or so. Now when I turn it to lights on it idles at about 6.5 volts, and when I rev it it really doesn't go up, in fact it drops a little bit. So Mark was right, if I ran with mag lights on the nighttime circuit, I probably would cook the battery very quickly.

As an aside, I made some strings of orange RTV last night, and stuffed a couple of them into the exhaust flange. Put one in, then fit the exhaust to seat it, then took the exhaust off and put another one in and put the pipe back on  So far, it seems to work very well.

 

Interesting things happening with the charging wires switched. .

When I have the nighttime charging wire hooked up to the "light on" part of the ignition switch, at idle it's about 6.5 volts, and the daytime circuit reads about 6.3.

When I swapped the daytime charging wire to the "lights on" position it only reads barely over 6 volts, and the night time circuit on the "lights off"position reads 7 volts.

I went for about a 15 mile ride with the lights on, and when I got home the battery at rest was reading 5.99 volts.

So I switched the charging wires to normal, and went for a ride of about 10 miles. When I got home the battery at rest read about 6.3 volts.

So apparently something is happening between the two ignition key positions. Maybe there's just more wires involved in the "lights on" position, and that reduces the charging voltage? Even though I don't have working instrument illumination bulbs, and have the tail light on the mag.

Where I ride, in this beach town and others nearby, I use the brake light and the turn signals a lot. I also ride on stretches on Pacific Coast Highway, but never more than a few miles before I come to a stoplight again. So I'm going to leave the nighttime circuit on the "lights on" position, and just keep an eye on the battery water.

Edit: The charging system seem to fluctuate, depending on the state of the battery. Now I'm getting 7+ volts on the "lights on" position, with the battery holding at 6.3 with the engine off. Interesting. In any case, I have some instrument lights coming today and will put those in. BTW the silicone strings are working very well for the exhaust. Seems like less noise from the front, and the pipe is far more secure.

I see you double grounded your voltage regulator. Did you run the yellow wire into the dark blue wire in that loom below the frame ???

You have to be careful on any US model past 1969.  There are two blues, one AC and one DC. 

Best bet is to connect to blue in the headlight bucket that goes to the gauge illumination bulbs like the Yamaha Service Bulletin says.  That will work on any of them... 

I tapped in to the dark blue wires inside the bucket, which as far as I could determine go the instrument lights. I think I posted a picture earlier in the thread, but I'll post another one. I have it double grounded just to be redundant, and because it was easy to do.

By the way, yesterday I stripped the original front fender and gave it a rattle can paint job with DupliColor DE1615. I disassembled it the night before and let the chrome parts soak in Evaporust.overnight. Even though my frame and tank are very rusty, the bike's looking a little bit better. I think it's more aerodynamic without the high fender I had on there as well. The lower fork tubes have a lot of "patina" as well, but I think I'll leave them as is for now. I previously did the same thing to the rear fender and the chain guard, that were both very rusty. 

I guess I'll have to post the pictures later because it looks like it's not working again.

You did it in headlight bucket and already posted perfect pictures... 

I was answering the question about tapping into blue "below the frame".  Bad idea and can fry new regulator and maybe other stuff if blue picked is DC....  and along frame it probably is except possibly on non-US bikes and very early US bikes. 

Hey Mark, I've been monitoring my battery voltage as I've been taking some longish rides. Usually when I get home it's reads 6.77 V, then about half hour later it settles at 6.20 V. Also no noticeable drop in battery fluid.

Now I'm getting really strong neutral, turn signal, and brake lights. I think for my kind of riding around town, it's going to be just fine using the head and tail lights off the mag.

Sounds great.