DC Voltage Drops While Running

[blaat!]

Your yellow wires will be connected in the alternator using a tag screwed to the alternator plate. Remove the connection to ground, but leave the two ends joined together and insulate them.

Thanks Max. I'll need to find a little more time to test this one, but I definitely will.

[blaat!]

I decided to go for the electrex full package from Nigel and that has fixed the issue. My old stator is now a paper weight.

As a thought, do you have a good earth ground to the engine from the battery? Something as simple as a corroded or poor earth will prevent the current getting back to the battery?

I'm committed to the 6V at this point and I'm learning a lot... like how stubborn I really am

Yeah, the battery has a nice fat ground wire bolted to the frame with the paint stripped away and some dielectric grease to prevent corrosion.

[mrkprsn]

I'm a stubborn 6V guy also. I would ground three ways; frame and not rectifier, frame grounded to rectifier, and negative battery post not connected to rectifier. Also try this test using the gray wire in the old rectifier instead of the red. The fact that your voltages are all over the place points to something although I haven't figure out what yet.

In Dave354's case his generator couldn't produce enough current for his headlight. Today you can use a LED bulb. I have one the uses only 10 watts. I'm worried that I may over charge my battery when running (the opposite problem).

[blaat!]

I made diagrams to hopefully help show the tests I did. Note the DC voltage is shown on the multimeter display

stock no ground.jpg

stock ground to batt.jpg

stock ground to frame.jpg

stock gray no ground.jpg

stock gray ground to batt.jpg

[blaat!]

electrex no ground.jpg

electrex ground to batt.jpg

electrex ground to frame.jpg

[blaat!]

knock off no ground.jpg

knock off ground to batt.jpg

knock off ground to frame.jpg

[blaat!]

Having the green/ground wire from the regulator connected to the battery in each case seems to be the closest.

Strange the stock regulator is showing negative voltage. I checked everything multiple times and the polarity on everything seems correct. I didn't try this, but I could just reverse the multimeter leads to see if the voltage is positive that way. That would be weird

[veloduke]

I still think that what is screwing this up is having your yellow alternator wires connected to ground.
I would remove that connection and use the Electrex regulator.
IMHO.

[blaat!]

Hi Max,
Yeah, that is my next move. I was doing the less invasive data collection first I will try to find time to do it this weekend. Thanks for the insightful idea! I plan to take photos in case it helps someone else.
Thanks!
Jim

[mrkprsn]

I'm missing it. Where are the yellow wires connected to ground (other than the generator is grounded inside, and the rectifier is grounded)? The pics show they are connected to the rectifier.

I am completely (except for generator) rewiring a 200GT which I am going to start a new thread about. After wiring, the bike wasn't charging (just like yours). I have a 40 watt (4 speed) generator. I ran the bike off the battery and tested both yellow wires. The voltages were 13 at idle and 22 when reved. I tested both wires for amps and got 8 at idle and 8.6 when reved. At this point I assume the generator is good.

The standing voltage of my battery is 6.35. I then connected all wires, with the lights (LED) and got 6.3 volts at idle and the same number when reved. The bike wasn't charging. I assumed it was the original rectifier. I tested it using the standard tests. I got OL instead of continuity when testing the red to yellow(s). So I assume it's bad.

I have a modern 4 wire rectifier. It looks exactly like this one. http://www.guzzino.com/noname3.html I hooked that one up and still the bike wasn't charging (with LED lights on). I tested it and found I was getting 50 Ohms from one green (yellow) to red and 145 Ohms on the other wire. I don't know what the Ohms should be but I know they should be consistent. Surprisingly I concluded that the new modern rectifier was bad.

I used a third original duc rectifier. This one had continuity from the yellows to red. When running (with the LED lights on) the voltage started at the standing battery voltage (6.3) but then started going up. After a few minutes the voltage was 6.5 at Idle and 6.65 volts when reved. A perfectly working 6 volt system would show 6.7-6.8 volts with the lights on so I'm not that far off and am concluding that the system is now working correctly (or as well as it can with the original equipment).

Have you tested the voltage at the battery when running with everything hooked up and the lights on? In the pic where you are getting 6.5 volts where the rectifier is grounded to the battery is close to what you want. Connect the rectifier to the battery and test voltage at the battery. I would also test the other yellow wire for volts and amps. See if the numbers are consistent. I would check all grounds.