Charging System Question. Yes, I've read it.

Back line:

Last week, tuesday i think, bike wouldnt start in the am. Noticed the light was dim. Bike has been running pretty damn good. Always room for improvement, but it is my daily rider, and getting better. I chalked it up to a fluke, maybe I left my headlamp on longer than I thought. 8 volts. Charged it. Starts on the first kick and runs for 8 days or so with no issues. Yesterday she started having trouble keeping a good idle. Checked the voltage this morning, 10.4v. Charged to 12.4, Start on the first kick. First thing i check was the headlight. It DOES NOT get brighter when reving. It used too. Checked that regularly on car bumpers in front of me or my garage door, you know, just keeping an eye on it.

Im going to be checking my charging system over the next...........variable time frame........but my question first is this:

"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."

Do I need to remove the green wire from the plug and run a jumper to the frame and leave the others plugged in , or do I leave the green wire plugged in and run a jumper from the green wire to the frame.

So,in short, to remove the green from the plug and ground it or leave it and run a jumper from the green wires pin to the frame?

I will also be testing the OHMs on the rotor later.

Slap test was good. Brushes look good and have what appear to be original yama markings for wear. Could be wrong about the markings. One is a little longer than the other, typical, but they look of good working condition. May order some extras just to have.

Also, I am at work and just realized this was an issue today and havent had a chance to hit the battery with a volt meter yet to see whats being sent back to the battery when revving. I will update with more details if necessary, but I will try to use the guide and do as much as possible with whats already available, I really just wanted to confirm the question regarding the green wire testing the reg/rec.

Thanks, you guys are awesome.

Hugh, hang one of the PMA's out to dry for me, I may need one.

EvenmoreXS said:

So,in short, to remove the green from the plug and ground it or leave it and run a jumper from the green wires pin to the frame?

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You don't need to get it out of the plug. It can go to ground or near ground in use normally, so it won't hurt it.

My charging problem turned out to be a p.o.'s hidden twisted connections that had gotten really bad over the years. It passed all the tests but they weren't testing for that. Before I discoved that I took the internet bad reputation of this charging system to heart! Works great when it's right though.

P.S. You can probably "back probe" the connector so you don't have to strip any wire. Just cram some test wire in the back in the housing so it touches the green wire connector.

xjwmx said:

P.S. You can probably "back probe" the connector so you don't have to strip any wire. Just cram some test wire in the back in the housing so it touches the green wire connector.

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Thanks XJ, I appreciate the quick response. Thats what I'll do. I rewired the bike completely in December and been riding daily since then, so luckily I dont have to chase any old wire gremlins. Been there done that. Every wire and connector is new, crimped and soldered. Dielectric grease on the pins.

I dont see anything WRONG with the xs charging system. Its simple design is easy to understand, easy to work on and easy to replace. When all is good it works just fine.

Well, one thing you can do, if it passes the green wire test, is look for the 14.x volts at places other than at the battery. That might help you zero in on a poor connection if there is one. Since the wiring is new I'd bet on a bad reg/rect if the rotor and stator tested good. The green wire test should tell you.

But another thing to look out for is a bad crimp on the component side. I assume you just crimped the harness side, if you're still using connectors. I had one of that too, come to think of it. Where the wire is exposed at the crimp it can decay away and such.

And yet another thing to look for is bad connectors imitating bad components. For example if the green wire connector was bad you could ground it all day and it wouldn't change anything, and you'd think you had a bad reg/rect, then if you put a new one in it wouldn't change anything if the bad connector was on the harness side.

Thanks xj, I'll hit em 1 at a time. Busy evening but I did have time to just check with a volt meter. 12.4v when i left this morning. 11.45 when I got home. The voltage increases NONE when revving. Gonna check the green wire in a bit and those connections.

You can ground it right at the brush also, remove the round cover and there you go.
You probably could do it with a screwdriver.
If that doesn't do it, check stator any two white to white about .6 ohm, infinity to ground. And the rotor; between 5 and 6 ohms.

Rotor reads 6.5 ohms. - .6 ohms that i got when I crossed the probes. Should be 5.9 ohms.

Gonna check the white wires and then the green wire test if its not too late.

Thanks

Yup 5.9 sounds good you had me worried with the 6.5

Stator test is with the stator unplugged....

I unplugged the stator, brushes were already out, I probed white to white on the plug for all three wires in all combinations and got 1.1. - the .6 when I crossed probes so that would be .5 . That should be ok I think.

yup that sounds good, infinity any white to ground?

300.000 Blinking. Open basically.

Sounds like you found out what happens if you ground the wrong brush.....

gggGary said:

Sounds like you found out what happens if you ground the wrong brush.....

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??? If you saw my post before i edited it, sorry, had a brain fart. Brushes were in. Both brushes touching the rotor means continuity across both on the green wire.



Before I hook up the battery and start her. Will this work?

Green brush has a green ground wire that goes to a welded on tab thats threaded for my side cover.

If i start her and I see 14.5 volts or so at the battery when revving, that means the reg / rec is bad.

Right?

That should do it basically if it charges at all it points at the regulator or it's wiring.
Do not over rev if the voltage goes up, the stator can put out a lot of volts which can be hard on other parts. Grounding the brush is like running the alternator at full throttle.

So, no need to do too much revving. Just look for more voltage than the battery has when its idling. Maybe a throttle bump just to see if it rises a bit.


Is that right.

My money's on the rectifier.
Slap test ok - rotor/reg working
Battery drain down - leaky rectifier (if it's on the battery (unswitched) side of ign switch)

Thats my thinking too. I'll know soon.

12.44 v sitting off. Starts on first kick. Voltage goes to 12.77 immediately. Couple quick revs and I see 14.5 -15 v.

Looks like i need a Reg/Rec.