TOPIC:

www.electrosport.com has a very good charging system troubleshooting page.

79MKII wrote: ...even with the key off, or the ignition switch completely disconnected for that matter, the motorcycle will start and run if I kickstart it...When I tested the ylw/red lead that powers the coils (and ignition), it switches on and off as normal with the key and / or kill switch. I then left the test light connected to the ylw/red wire and kicked the motor....the test light flickers even with the ignition off. Somehow, any time the engine is turning over, power is getting to the ylw/red wire that feeds the coils (comes out of harness under tank). Even with the ignition completely disconnected (power and both coil feeds) the symptoms are the same (I thought the power might be feeding back through the ignition). BUT...with the kill switch off, the power does NOT feed through when kicked....

Perhaps handlebar position is interacting with a frayed harness wire.

Would observe the test light while moving the handlebars through their range.

Good Fortune!

Received my "new" regulator today (used) and the problem is fixed. It was 100% the voltage regulator causing the issue. Very simple fix once you find it...but that's the tricky part.

Now I have to figure out if I just wired the new regulator incorrectly or did the $100+ new part go bad that quickly??

Kinda makes you wonder how many other bikes are out there that will start/run without the key being on? If it were me, I'd be contacting the supplier of the other regulator/rectifier and notify them of potential problems..

Now you have me wondering if the aftermarket regulator I got has gone bad too. My issue is a bit different though, when I shut mine off the engine does turn off but all the key "on" lights stay on even if you remove the key. After a cool down time of several minutes it will turn off if you put the key back in and turn it to "on" then "off". Guess I'll be looking at the reg now as a suspect too, thanks!

Wow....that's a strange one. I would've never guessed the regulator was to blame for my problem, so it's worth looking at. Just unplug it and see if the symptoms change.

79MKII wrote: Received my "new" regulator today (used) and the problem is fixed. It was 100% the voltage regulator causing the issue. Very simple fix once you find it...but that's the tricky part.

Now I have to figure out if I just wired the new regulator incorrectly or did the $100+ new part go bad that quickly??

It looks to me, in your photo, that you have the red output-wire on your reg/rec wired to the brown wire of the harness. I don't think that is correct, if that's the way you have it.

The brown wire, on the old regulator, was for the regulator to sense the system voltage. It should not be used as the wire that the output of the reg/rec is connected to.

Usually, on a 5-wire, 3-phase, reg/rec for permanent-magnet alternators, that red wire would go directly to the battery (with an optional fuse in that line).

If your bike originally had separate regulator and rectifier, the output of the combo reg/rec would go to the wire that was connected to the output of the rectifier. Actually, in your case, the entire reg/rec combo would get wired in place of the original rectifier (if your original rec and reg were separate).

The way you have it wired, anytime the motor turns over, the bike will have power even if the ignition switch is turned off. Also, the power will not be filtered by the battery, so when you switch the bike off, many short pulses of high voltage will likely hit the bikes electrical system until the motor actually stops turning. This can eventually damage electonic devices including the regulator.

EDIT: ignore this. My mistake. It is a regulator-only, not reg/rec combo. See below.

@LOUDHVX....thanks for the info. I will definitely be taking a closer look at how I wired it...can't remember for sure. Can't find paperwork that came with the regulator either (if there was any). WTF has happened to my memory? Seems I figured that out once but now I forget....

Not sure if it matters, but the new regulator is "regulator only", separate rectifier still in place.

After going back and looking at the pictures....what powered the stock regulator originally if not the brown? The only other wires are black(ground) and the 3 for the stator, I think (pink, light blue, yellow).

Yeah, sorry, my bad, I assumed the regulator in your photo was a regulator/rectifier combo. You said "regulator", but I missed the part about it using a separate rectifier.

You have it right. Brown powers the regulator.

You have it right. Brown powers the regulator.

If the regulator has an internal short, where the AC side can get to the brown wire, that would explain the power pulses you were getting with the key off, and kicking the bike. That would make sense since you figured out the regulator was bad for sure.

However, that type of regulator usually does not fail in a way that would allow power to come out of the brown wire (to feed the system when the key is off). It's strange, or maybe there is some wiring issue as you suspect.

Yea, I'll have to ride it for a while and see if this regulator fails too. Hopefully it was just the part that failed and not another problem that caused it.

I wish I could remember why I wired it the way I did. I'm guessing I had instructions of some sort but I'm not sure. Hopefully I can find wiring instructions for that specific regulator. The brown being for voltage sensing sounds really familiar.