Ok, explain this electrical gurus.

[gsrick]

A little background first. We have a 2000 Yamaha R6 my boss bought a month ago. First thing that seemed odd was the starter every now and then would stay running. You would have to disconnect the battery to shut it off. The kill switch wouldn't do it, the key wouldn't do it. I think it's got to be the solenoid getting stuck from carbon build up, so the kid I'm kind of training while he's going to MMI, gets the job of replacing it. We have one, it's not an exact match, but it's close enough. So he replaces it and does the inspection.

I'm told everything is ok, but it's not charging. I test the stator leads and get exactly what the manual said I should get, 46+vac at 4k. I test the R/R and I get some bad readings doing the diode tests. Fast forward a week and the R/R arrives. The kid is in school, so I get the honor. After the install I test the charging system and I get around 14v @ 2k, but it decreases as the rpm build. At 5k, I'm getting 13.35v, still charging but it's strange that the voltage would decrease instead of increasing. I have a portable voltmeter I rigged for test rides, mainly for GSXR600's, but sometimes I put it on other bikes to monitor the voltage.

I have seen R/R that I've installed on GSXR600 test low right after install, but get better as I go along my test ride. Example is, preride test 13.7v and eventually get 14.3v around 1/2 to 3/4 of the 10 mile test ride. With that in mind I install my tester on the R6 and take it for a test ride. No change what so ever. At cruising speeds I get 13.3-13.5 volts as I slow down at stop signs, it increases. Best is 14v at 2K and it drops a little at idle. I'm not happy, but the boss says it's charging, move on to something else.

Ok now were up to yesterday. The R6 has been in the back showroom for about a week or two and I hear the salesman try to start it and I hear the starter running on and on. I stop what I'm doing and check it out. Just like before, nothing will shut it off. I push it back to my area and try to get the seat of quickly, but the battery wears down before I can get the seat off.

I pull the negative lead off the battery and hook up a charger to recharge the battery. In the mean time, I'm smacking the solenoid thinking that for some reason the new one is sticking on. This method works on old solenoids that wont work, so why not, eh. I'm looking at the harness, checking for continuity here and there, the starter button, whatever crosses my mind, but I get pulled to fix other things. That's ok the battery needs to be recharged anyway.

Here's where it get weird. Later I get a chance to mess with it again. I hold the negative battery lead to the post and nothing. I don't want to bolt it to the terminal, in case the starter runs on again, so I hit the starter button and it fires up, but the starter is still going. I lift the negative lead off the battery and the bike keeps running. WTF? That's not suppose to happen. I can see the headlights shinning off the wall, but they seem to be flickering a little, not as strong as when the negative lead is connected. I twist the throttle and it increases rpm. I turn off the ignition switch and the engine dies.

Another weird thing is if I do a continuity test with the negative lead disconnected with one test lead clamped to the neg lead and the other test lead to the negative battery terminal i get the continuity buzz. I started it multiple times and it keeps running when I remove the negative lead from the battery. The other end of the negative lead is bolted to the top of the engine case. I've looked at the wiring diagram and as far as I can tell the harness wires from the battery and solenoid are going where they are suppose to.

Ok gurus, how is this happening? The positive lead is connected on the battery, but that is all. I've seen older cars with alternators be able to run if you take off a battery lead, but I have never seen that happen with a stator based system. It has a new battery in it.

I'm off for the next two days, so I hope someone can shed some light on this.

[Steve]

It's not electrical.

The starter clutch is stuck.

.

[posplayr]

Look like the R6 is a standard PM alternator with shunt R/R. I think we have seen these before somewhere.
Don't disconnect battery leads from a running bike(bad news).
You could probably apply the Quick test diagnosis and it would tell you you have poor connections between the battery and the R/R.
Do the Stator pages Phase A and measure the voltage drops at 5K RPM.

[gsrick]

Look like the R6 is a standard PM alternator with shunt R/R. I think we have seen these before somewhere.
Don't disconnect battery leads from a running bike(bad news).
You could probably apply the Quick test diagnosis and it would tell you you have poor connections between the battery and the R/R.
Do the Stator pages Phase A and measure the voltage drops at 5K RPM.

What is a PM alternator? Also when your in a rush(panic mode) to stop a starter for run on, disconnecting the battery after nothing else works is what has to happen. I may have written it incorrectly, the engine will stop running with the kill switch and the ignition turned off, but that did not stop the starter from continuing.

How can my multimeter register continuity from a disconnected negative battery lead and the negative terminal. If I move my test lead from the negative battery terminal to the positive terminal, the continuity buzzer does not sound. It's like there is an invisible wire.

[gsrick]

It's not electrical.

The starter clutch is stuck.

.

I can stop the engine from firing with the kill switch, but the starter keeps running until the battery is disconnected.

[GregT]

Has it had an immobiliser or an aftermarket alarm system fitted by the PO ?

[Rijko]

What is a PM alternator?

PM = permanent magnet.
Here's a nice writeup on the different alternator systems.

i'm not clear on the details of disconnected negative leads but the battery is just a buffer.
The alternator can provide power to keep the engine running if the RR is grounded to the chassis - you would still have positive and negative, even with the negative terminal removed from the battery.
Since the battery buffer is not there anymore that explains the flickering headlight. (an empty or broken battery would show the same behavior of flickering lights)
Electrically isolating the RR from the chassis should solve that.

the engine will stop running with the kill switch and the ignition turned off, but that did not stop the starter from continuing.

If the starter continues even with the engine turned off, it has to feed off the battery because there is no other power source.
A solenoid working properly gets activated by a signal wire, and connects the high amp wires to provide power
to the starter. Somehow, enough power makes it through the solenoid to the starter to continue cranking.

I can think of 2 scenarios the starter will continue with a non running engine :

- solenoid is ok but the signal wire keeps on providing 12v even with kill switch and ignition turned off, it may short to 12v somewhere in the cable harness. Next time this happens, if possible disconnect the signal wire from the solenoid. Hope that stops the cranking.
- solenoid is bad, does not release even when no 12v on the signal wire.

I think your first hunch was right, focus on the solenoid first.

[gsrick]

Has it had an immobiliser or an aftermarket alarm system fitted by the PO ?

No, at least not that I can tell. We did have a bike recently that did have one and the kid removed it. It's possible it was this bike. I'll have to ask.

[gsrick]

PM = permanent magnet.
Here's a nice writeup on the different alternator systems.

i'm not clear on the details of disconnected negative leads but the battery is just a buffer.
The alternator can provide power to keep the engine running if the RR is grounded to the chassis - you would still have positive and negative, even with the negative terminal removed from the battery.
Since the battery buffer is not there anymore that explains the flickering headlight. (an empty or broken battery would show the same behavior of flickering lights)
Electrically isolating the RR from the chassis should solve that.



If the starter continues even with the engine turned off, it has to feed off the battery because there is no other power source.
A solenoid working properly gets activated by a signal wire, and connects the high amp wires to provide power
to the starter. Somehow, enough power makes it through the solenoid to the starter to continue cranking.

I can think of 2 scenarios the starter will continue with a non running engine :

- solenoid is ok but the signal wire keeps on providing 12v even with kill switch and ignition turned off, it may short to 12v somewhere in the cable harness. Next time this happens, if possible disconnect the signal wire from the solenoid. Hope that stops the cranking.
- solenoid is bad, does not release even when no 12v on the signal wire.

I think your first hunch was right, focus on the solenoid first.

My brain wasn't working right last night, it was late when I posted that question. I woke hoping nobody saw the PM question.

The R/R on this bike is mounted on the side of the plastic battery case and it is a single 5 pin connector directly into the wiring harness. If it is grounded to the frame, then there has to be a short to ground somewhere in the harness? This bike has a lot of after market PO installed connectors and the solenoid my boss bought may be of questionable quality. You know the saying, "you get what you pay for".

I did talk them into buying a Power Probe to help me when I run in electrical issues, but it is the cheapest model they sell.

[argonsagas]

Looks like you already have your answers, Rick, but I wil toss this in for GS riders who happen to have their R/R and stator fried while riding, and find the bike just sits on the side of the road after that.


Remove the multiple wire connector at the R/R and touch nothing else in that area.

That disconnection will allow the bike to start and run on battery alone.

You will still need to repair/replace one or both components but that simple trick means you can ride some distance to get where you need to be. How far you can go depends on your battery. I needed 7 or 8 miles and the GK did that without problem with the headlight still working as it was very dark, no highway lights, which made the headlight essential.

[80GS850GBob]

PM = permanent magnet.
Here's a nice writeup on the different alternator systems.

i'm not clear on the details of disconnected negative leads but the battery is just a buffer.
The alternator can provide power to keep the engine running if the RR is grounded to the chassis - you would still have positive and negative, even with the negative terminal removed from the battery.
Since the battery buffer is not there anymore that explains the flickering headlight. (an empty or broken battery would show the same behavior of flickering lights)
Electrically isolating the RR from the chassis should solve that.



If the starter continues even with the engine turned off, it has to feed off the battery because there is no other power source.
A solenoid working properly gets activated by a signal wire, and connects the high amp wires to provide power
to the starter. Somehow, enough power makes it through the solenoid to the starter to continue cranking.

I can think of 2 scenarios the starter will continue with a non running engine :

- solenoid is ok but the signal wire keeps on providing 12v even with kill switch and ignition turned off, it may short to 12v somewhere in the cable harness. Next time this happens, if possible disconnect the signal wire from the solenoid. Hope that stops the cranking.
- solenoid is bad, does not release even when no 12v on the signal wire.

I think your first hunch was right, focus on the solenoid first.

Agreed...I'd suggest a temp toggle switch inline of the signal wire. Fire up the starter and if/when it keeps running flip the switch to off to see if that kills it. Sounds like your getting feedback voltage that's enough to keep the solenoid energized from another source.....shy of the new solenoid sticking - it's getting voltage elsewhere. Shorted switch or miswire...which might explain the low charging voltage when it's running...a short is drawing down the voltage.

The fact that the kill switch kills the running motor is another circuit, and it sounds as though it's doing it's job. The starter circuit has a problem -if only that it's not fed voltage like it needs.
Had a similar deal eons ago with a car draining the battery, things not working like they should and hard starter problems {low voltage/not continuous starter running though}- turns out one of the power window switches was shorted...took nearly 3 days to trace it. Was a '68 continental ragtop though - was worth it.

[JTGS850GL]

The starter running, even when the kill switch is on, could indicate that the starter solenoid is getting stuck. Try to start it and have a meter ready. If the control voltage to the solenoid isn't present and the starter is still turning, then it's the solenoid. If you still see voltage, even when the starter button is released and the kill switch is opened, then it's wiring upstream.

[80GS850GBob]

The starter running, even when the kill switch is on, could indicate that the starter solenoid is getting stuck. Try to start it and have a meter ready. If the control voltage to the solenoid isn't present and the starter is still turning, then it's the solenoid. If you still see voltage, even when the starter button is released and the kill switch is opened, then it's wiring upstream.

"I thought"......the starter wasn't part of the kill switch circuit, kill was only for the coils?
Agreed on the seeing voltage it's something upstream...could even be a bad ignition switch letting voltage thru via a short in it...but most likely something plumbed incorrectly....assuming the solenoid is good. Got another to try?
edit= clutch handle switch was part of the starter kill....possible bypass for that done incorrectly?

[JTGS850GL]

If the ignition key won't kill the starter then it's the solenoid for sure. That's unless there are some serious rewiring that's going on. Could be a fused wire in the harness. Checking the voltage at the coil wire of the starter solenoid would verify if it's a mechanical issue with the solenoid or an electrical issue upstream.

[80GS850GBob]

If it's not the solenoid, I'd regretfully say pull the tank and start looking at what the PO did to the wiring harness...all of it.{ugh}