Winter project: upgrading time! (R6 forks and more...)

[arcticXS]

Without a regulator, the alternator will not give any output, so that should be completely safe.
I really cannot see how the tacho should affect the engine, with the sensor wire wrapped around the HT lead. When connected to a coil terminal it COULD, but is unlikely.
To me, it seems that your ignition "box" is seeing some kind of disturbance from alternator or RR. Where is it physically located? Maybe there are some kind of transients or "ripple" in the DC from the RR? And that your battery may be to small to dampen this?

 

[Jim]

How can you tell?

If it's a repop, the Yamaha part number on the ring plate will be missing (green arrow).

Can someone confirm its save to start the bike without an R/R hooked up?

Yes, perfectly safe. I'd suggest you do that and see if the rotor's magnetic field is causing interference with the TCI trigger signal.

 

[Jim]

I know of one case first hand where the bike's iggy was acting up much as you describe with the R/R connected. With it disconnected it worked fine. The problem turned out to be the aftermarket rotor. Apparently, the copper rings are paper thin and allow the magnetic field to interfere with the trigger magnet. We put an OEM rotor on it and it cured the problem.

 

[Jim]

Watch toward the end in this video. I demonstrate how the copper rings shield the trigger magnet from interference. (starts at about 1:50)

 

[Brassneck]

My sense is the tach and R/R are separate issues...so I would start with trying to address the important one first, the R/R. I think this was suggested but the R/R could be incorrect for the type of charging system you have. Earlier XS vs. later style? Are all the R/R you have for your year? And why did you replace the R/R in the first place? Perhaps all of them are incorrect for your year? Just thinking out loud here.

 

[Jim]

Just had another thought.... you said the rotor has been rewound. Perhaps (yes, this is just an idea) they wound it opposite the way the factory wound it. Again, just theory... but that might change the polarity of the magnetic field in the rotor.... opposing the polarity of the trigger magnet. You could try swapping the wires to the brushes. See if the iggy system likes that better?

EDIT: Iggy = Ignition

 

[Bjorn]

Good info you guys! Tomorrow I will test the bike with the R/R disconnected. In the meanwhile I checked the following things:

The location of the R/R is all the way at the bottom of the bike. I did this because last year we talked about "dirty" electrical components emitting lots of noise. Apparently the R/R is one so I mounted it here:

Fascinating info Jim!! I check the outer ring and I think it's a Yamaha piece. Secondly I put an awl on the trigger magnet. Can definitely tell is magnetic but it's hard to compare through a screen.

Now for something I find interesting. I poked around with the ol VOM. Check the following:

-Batt neg to ground in TCI connector: OK.
-Cross checked All the terminals in the R/R on the bike side connector. First glance nothing. I thought maybe there are wires touching in the loom. However one brown wire would flick to black. So I went a scale up on the ohm meter. 2000ohms. Then I found this:

On lead on the case but on the black lead in the terminal it's the same.

I rechecked with the main fuse unhooked, still around 1900 ohms.

Now I got to look at the diagram I made and the physical location of the wires. There are two browns here because I want to be able to unhook the R/R. This brown lead goes to the ignition barrel if I'm mistaken.

I'll do a follow up tomorrow. Let me know if I should be looking for something specific.

 

[Jim]

Yes, that's an OEM rotor.

Can you clarify exactly what wire you're reading that 1900Ω's on.... and where it's going?

 

[gggGary]

Yup you can run it til the battery poops out, with the headlight off prolly 20-30 miles...

 

[gggGary]

PS you have looked at every wire EXCEPT the harness that passes behind the sprocket, correct?
Several of us have found cracked "hanging by a thread" wires in that bundle, area. One bike I had was like yours, working but running poor, found a pickup wire nearly broken in two.
Jim Holmes "case of the too thin slip ring"
https://www.xs650.com/threads/xs650sk-runs-poorly-when-warm.56771/#post-633606

 

[Jim]

PS you have looked at every wire EXCEPT the harness that passes behind the sprocket, correct?
Several of us have found cracked "hanging by a thread" wires in that bundle, area. One bike I had was like yours, working but running poor, found a pickup wire nearly broken in two.
Jim Holmes "case of the too thin slip ring"
https://www.xs650.com/threads/xs650sk-runs-poorly-when-warm.56771/#post-633606

Thanks Gary. I'm gonna add that comment here... if for no other reason than to get it more exposure and hopefully get some more answers to the "weak magnet" question.

"I'm just gonna throw this out there as a fwiw... seems as good a place as any. During my rotor tooling buildup, one of the tests I did (incidentally) was looking at the TCI magnet. One of the videos I did showed how the copper in the faceplate almost completely blocked the rotors magnetism. allowing the TCI's pickup to "see" the tiny TCI magnet in amongst the rotors strong mag. field. I never mentioned it or videoed it but the magnet is felt on the backside of the faceplate too. What that means is every time the rotor energizes, it refreshes (for lack of a better word) the magnetism in the TCI magnet. So I'd be at a loss to explain how the little magnet weakens.
So why do some guys disconnect the reg/rec (killing the rotor) and find that the TCI works when the rotors not magnetized? Here's my theory... backed up with some anecdotal evidence...
I hope @delagem doesn't mind me tagging him here, but he got a hold of me because his bike was doing the "weak magnet" thing. Worked OK with the reg/rec disconnected, but ran like crap with it hooked up. His bike came to him with an aftermarket rotor... a Chinese one. A light went off and I started searching through some old articles I'd read. There was a member here a while back (name eludes me right now) that had a Chinese rotor ( you were involved in this thread Gary) that didn't run true. He put it on a lathe to true up the faceplate and promptly ate the copper rings. Yep, apparently the copper in the Chinese ones are paper thin. No surprise there is there? So, based on the idea that the paper thin Chinese repops were allowing the rotors magnetism to "bleed through" and confuse the hell out of the TCI pickup, I sent Mike one of my OEM rewinds. It fixed his bike.
So, if your bike acts like Marty's here and disconnecting the reg/rec fixes it, look and see if you're rotor's OEM or a repop. If it's a repop, I'd suggest replacing it with a good OEM 'afore you throw your money at another Chinese copy.
If anyone has experience otherwise, please speak up. It'd be nice to get some more data on this and see if my theory (backed up by one example ) holds up."

 

[Bjorn]

Yes, that's an OEM rotor. View attachment 192935
Can you clarify exactly what wire you're reading that 1900Ω's on.... and where it's going?

Good question, I will look into that tomorrow! It's night time here now.

I red the post of the guy with the Chinese rotor. What I will do tomorrow is use a dial indicator to see if the face of the rotor is running thru.

And if I understand your theory correctly the magnet should be recharged by the rotor? Is there a methode we can use to get a basic comparison in magnet-force? I don't know what unit that would be. But maybe we can see if a certain object with similar Shape and weight can be hung on the face of the pick up magnet.

PS you have looked at every wire EXCEPT the harness that passes behind the sprocket, correct?
Several of us have found cracked "hanging by a thread" wires in that bundle, area. One bike I had was like yours, working but running poor, found a pickup wire nearly broken in two.
Jim Holmes "case of the too thin slip ring"
https://www.xs650.com/threads/xs650sk-runs-poorly-when-warm.56771/#post-633606

Well last year I looked into these wires when I had the weird problems to. Visual inspection didn't bring me anywhere. But it's a fact that these wires (stator, brushes and tci pick up) for the engine part are still original.

I would like to change them but! For example the pick up is a sealed unit with wires coming out. I don't see a decent way of replacing the wires. Yes I could cut them and crimp on new ones. But i would still be left with a extra failing point and still a small piece of old wire.....hope you understand what I'm saying.
I did solder on new wires years ago, these are still in place.

I would like to have 100% new wires. Maybe I should look into this as well.

 

[Jim]

And if I understand your theory correctly the magnet should be recharged by the rotor? Is there a methode we can use to get a basic comparison in magnet-force? I don't know what unit that would be. But maybe we can see if a certain object with similar Shape and weight can be hung on the face of the pick up magnet.

Yes, I think it's being re-magnetized whenever the rotor is energized. I can't think of a way to prove (or disprove) that though.. I suppose a method of measuring the amount of weight the magnet will hold could be devised, but it would involve removing the rotor to test it.

Just quick and dirty.....
The magnet will hold 8 16d nails for a total of 61 grams.
9 nails at 68 grams wouldn't consistently stay attached. I tested 5 rotors with similar results.

 

[gggGary]

I think Jim nailed it!
Just from memory and comparison metal attraction I have seen stock rotors with weak magnets. Some had spend hard years out in weather.

 

[Bjorn]

Thanks Jim! I might be taking my rotor off to see.

This morning I tested the bike with the R/R disconnected. It's started and ran perfect. Bike is idling nicely and the tacho is dead stable with the RPMs.

Next I measured the total runout of the face of the rotor. Measured on a slip ring since that's where the brush is contacting.

Rotating the crank by hand I got a total runout if 0,1mm (0,004inch). Can't find any specification but I recon that's OK.

While measuring this I discovered that it is possible to axially move the crank about 0,4mm ( 0,016 inch). I don't know that the limit is for this, looked in the manual but dont really know if this spec is in here:

Next that 2000ohm resistance...

 

[Bjorn]

Following that brown lead it connects to the ignition switch hot side. That basically means this could be connected to any of the power circuits on the bike. I started to pull fuses one by one until I located in what circuit this was going on.

I isolated it to circuit 4 which powers:

- flashers
- brake switch to relay (low power circuit)
- km sensor
- instrument cluster aka tacho/speedo.

Next i started disconnecting the indicators, made no change. Then I disconnected the connector for instrument cluster power in the headlight. The diagram doesn't show this connector but after I unplugged it, i did not measure that 2000 ohm resistance in the bike wiring loom anymore. checking the instrument to ground, its showing that 2000 ohm. I believe and please correct me if im wrong! that this is some internal resistance of the instrument cluster....

I think its a dead end.

 

[Bjorn]

yesterday I found an interesting old topic about a guy with very similar problems. This topic: http://www.xs650.com/threads/weird-electrical-bug.18961/

I you got time, read it! its interesting. If not the conclusion for him seemed to be what Jim mentioned: he had to swap the rotor brush leads.

Just had another thought.... you said the rotor has been rewound. Perhaps (yes, this is just an idea) they wound it opposite the way the factory wound it. Again, just theory... but that might change the polarity of the magnetic field in the rotor.... opposing the polarity of the trigger magnet. You could try swapping the wires to the brushes. See if the iggy system likes that better?

EDIT: Iggy = Ignition

So I'm going to try that next

 

[Bjorn]

So I switched the green and brown terminal in the wiring loom to basically switch the brush leads. And It made no difference. Bike would still start and charge but is not running ok.

Unplugging the R/R again: super smooth idling.

 

[Jan_P]

I am a bit skeptical on the weak magnet theory.
Cant a measurement be done with the rotor in place perhaps a piece of string and a horizontal line out from the bike over an edge and there
hang the nails Jim have on picture

a) If Carmo and perhaps others have sold a number of ignition systems ..they would have heard about Weak magnet.

b ) If a Chinese Rotor is not working .. may lead to issues for others

c ) If the magnet is an issue wont that be a problem for the for the Gonzo Project. ?

Regarding the difference having the rev counter left and right and strobe light. Difference .
I tried to read a little last night

Twisting the rev counter pickup wire around the other wire will I believe consume Power from the coil wire
I may be wrong here not expert but the twisted coil act as a pickup : And sends a signal to the rev counter
post #181
As proposition the " Extra " power consumption does not work on the left side ----- it does on the right side
I would then assume weaker power at the left side .
The switching leads and plugs left to right would give info on that.

I am still at the wiring .and interference.

 

[Bjorn]

I am a bit skeptical on the weak magnet theory.
Cant a measurement be done with the rotor in place perhaps a piece of string and a horizontal line out from the bike over an edge and there
hang the nails Jim have on picture

a) If Carmo and perhaps others have sold a number of ignition systems ..they would have heard about Weak magnet.

b ) If a Chinese Rotor is not working .. may lead to issues for others

c ) If the magnet is an issue wont that be a problem for the for the Gonzo Project. ?

Regarding the difference having the rev counter left and right and strobe light. Difference .
I tried to read a little last night

Twisting the rev counter pickup wire around the other wire will I believe consume Power from the coil wire
I may be wrong here not expert but the twisted coil act as a pickup : And sends a signal to the rev counter
post #181
As proposition the " Extra " power consumption does not work on the left side ----- it does on the right side
I would then assume weaker power at the left side .
The switching leads and plugs left to right would give info on that.

I am still at the wiring .and interference.

A. Maybe? How could we know?
B. Checked for me, Yamaha rotor.
C. Don't know enough about this ignition.

Regarding the tacho pick up, it didn't seem to make a difference. Left, right, to the coil. Only removing the R/R will result in the bike running smooth + tacho being smooth.

I'm now in the process of removing this rotor. To do the Jim-test.