Author Topic: ABS newb: what do I need to know?  (Read 3070 times)

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#20

Offline jm2

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Re: ABS newb: what do I need to know?
Reply #20 on: 27 November, 2020, 11:17:47 PM
Unsure how we've gone from ABS to suspect stator RR fault one thread !
- It ought to be a faulty circuit (inc. RR, any other bike a secondary alarm) but as these RRs don't seem to do that sir, I'm opening the book on a earthing stator.
Only do it right - no bodging please.   Keeper of the failed stator list.   John.

#21

Offline Art

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Re: ABS newb: what do I need to know?
Reply #21 on: 28 November, 2020, 12:55:21 AM
Morning John, can earthing stator produce 13.9v at 3,000 RPM?

#22

Offline sambaman

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Re: ABS newb: what do I need to know?
Reply #22 on: 28 November, 2020, 04:18:21 PM
My fault, I mentioned that the abs had swallowed up my spare stator storage space thag I had on my last biffer and we went from there.

The stator is a brand new electrex one that I installed last week. The battery was replaced at the same time simply because the bike is new to me and I'd rather know how old it is.

I'll do the parasitic draw test tomorrow if the weather is ok (no garage) but I'm pretty convinced that the RR is playing up so I've got one in the post.

Thanks gents.

Chris

If you can't change your Mark 1 stator with your eyes shut: you haven't been riding your bike enough....

#23

Offline jm2

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Re: ABS newb: what do I need to know?
Reply #23 on: 28 November, 2020, 04:39:44 PM
*Originally Posted by Art [+]
Morning John, can earthing stator produce 13.9v at 3,000 RPM?

Unsure, but it isn't holding 13.9v it dropped to 13.4v.  But there is definately something cuckoo here.

13.5V at idle rising to 13.9V by 3000rpm and then it starts to decrease if you hold it steady or increase the revs
Implies the RR is overheating/poorly.  But there aren't any/many reports of biffer standard RRs doing this; now an earthing stator (or somewhat earthing) could upset the RR and fail to produce output at more revs (the earthing point being, as it happens, the same potential as the battery -ve).

Either that, or there's some right dodgy connectors that need rebuilding.  But, only an opening book - I've seen nothing else so far to suggest anything else.  We need the results from the parasitic drain next.

NB. Isolating the 3-ph to the RR and measuring the current would be after that.

If the stator is earthing and this voltage falls then I'd suspect both (in this case only).
Only do it right - no bodging please.   Keeper of the failed stator list.   John.

#24

Offline Art

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Re: ABS newb: what do I need to know?
Reply #24 on: 28 November, 2020, 07:13:28 PM
Yes John, normally I would test for standby current drain after checking the battery's initial level of charge but I felt we could skip that step here because there was no complaint of a flat battery and the battery's initial level of charge was good at >12.6v. With 13.9v at 3,000 RPM dropping to 13.4v at 4,000 RPM my prime suspects were the RR or a wiring failure between the RR and battery. The voltage drop test results eventually proved the wiring to be good at <0.2v. Which left me suspecting the RR but without hands on diagnosis I couldn't be 100% sure.

I don't understand how a parasitic drain could cause the voltage to drop from 13.9v at 3,000 RPM to 13.4v at 4,000 RPM. I've never come across an intermittent shorting stator either but there is sure to be a first and it does sound plausible. If I understand this correctly you're suggesting the stator coils may start shorting to ground at 4,000 RPM but not at 3,000 RPM, possible due to the coil windings heating up? Perhaps we need to do a dynamic output test of the stator.

*Originally Posted by sambaman [+]
The output of the stator is healthy as expected but at least that is ruled out.

Although he never said how he tested it, sambaman here's another test for you - idiots guide to testing the stator output as below, you may need an extra helping hand. Don't be put off carrying this test out on a new stator, it doesn't take too long especially with the RR already exposed and it will give you a reference point for any future diagnosis.

Select the 200v AC range on the multimeter, yes that's the 200v AC range. Disconnect the stator to regulator/rectifier three pin white connector.  With the engine running at 3,000 RPM test and note the stator output voltage between each pairing of the three yellow output cables from the stator, that's three readings. Now repeat the test this time with the engine running at 4,000 RPM, that's another three readings. Expect each set of three readings to be equal with the second three readings being equal to or higher than the first three readings and around 40v AC. 

#25

Offline sambaman

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Re: ABS newb: what do I need to know?
Reply #25 on: 29 November, 2020, 07:47:27 AM
*Originally Posted by jm2 [+]
Implies the RR is overheating/poorly.  But there aren't any/many reports of biffer standard RRs doing this; now an earthing stator (or somewhat earthing) could upset the RR and fail to produce output at more revs (the earthing point being, as it happens, the same potential as the battery -ve).

On my last biffer I replaced the stator 3 times in 70k miles. Each time using an electrex one. I've heard people say that after market stators are better than the Honda ones and are unlikely to fail. This is clearly not the case and it seems even Honda agree since they redesigned the engine to increase the oil flow to cool the stator in the mk2.

That's why I ended up carrying a spare stator under the seat on european trips!

I also replaced the RR on another occasion - assuming at first (with good reason) that the stator would be at fault AGAIN. But after testing it, I found the stator to be good. The battery also seemed fine so, without much idea how to test anything else, I replaced the RR and the problem was solved. So I know from experience that they do fail. Maybe people don't post about it much.

I'll do the draw test today, check the stator for continuity to earth and the stator AC output (again). But I've got a replacement RR on the way and they do allow returns so at least I can then see a clear before-and-after comparison.
Last Edit: 29 November, 2020, 07:50:32 AM by sambaman
If you can't change your Mark 1 stator with your eyes shut: you haven't been riding your bike enough....

#26

Offline sambaman

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Re: ABS newb: what do I need to know?
Reply #26 on: 29 November, 2020, 03:00:04 PM
Right then folks, thanks for your patience if you're still with me!

The draw test showed 0.11mA with the RR plugged in and 0.06mA with it unplugged.

There was no continuity to earth from any phase of the stator.

The AC output of the stator was good:

Approx 35V on each phase at 3000rpm
Approx 43V on each phase at 4000rpm

 :465:

As you suggested, it was a bit tricky holding the revs steady on my own whilst holding the multimeter in place. But I'm totally convinced that the stator is not the problem.

As I say, I am an amateur and I've not been tinkering for long but during that time I've experienced four stator failures on two CBF1000s, one on a 2004 fireblade (ie the same engine!) and one on a blackbird. So I've been through this a good few times already.

I've also had fun with the charging systems on two VFR750s: one that had a failed RR and one where I did everything I could to avoid any problems by upgrading the RR, replacing the charging harness and removing connectors etc etc

I'm going to be very surprised if a new RR doesn't make a massive improvement to the charging system BUT I am of course prepared to be wrong   :020:
Last Edit: 29 November, 2020, 03:04:55 PM by sambaman
If you can't change your Mark 1 stator with your eyes shut: you haven't been riding your bike enough....

#27

Offline jm2

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Re: ABS newb: what do I need to know?
Reply #27 on: 29 November, 2020, 04:02:08 PM
I'm thinking if the breakdown is partial, the extra voltage (with revs) could easily cause the breakdown.
But seeing the o/c voltages from the stator only moving form 35v to 43v 3k to 4k revs this is less likely here.


*Originally Posted by sambaman [+]
..
The draw test showed 0.11mA with the RR plugged in and 0.06mA with it unplugged.
...
It would be worth measuring with the RR plugged in and the 3-ph unplugged, but those figures stand as a pass.

I can see the RR is under a dark cloud but don't like the original voltage drops RR to battery terminals, they were rather high.

When you get the replacement through you'll have to do us a revised table of voltages/drops as I fear the RR will make everything look right but leave an underlying isssue somewhere.  More so as you've gone through so many stators compared with the average.


 
Only do it right - no bodging please.   Keeper of the failed stator list.   John.

#28

Offline sambaman

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Re: ABS newb: what do I need to know?
Reply #28 on: 29 November, 2020, 05:40:17 PM
*Originally Posted by jm2 [+]
IMore so as you've gone through so many stators compared with the average.

Worth pointing out that I've just acquired this bike with 40k miles so I don't know if it's the first stator failure or not but it was fried on arrival annoyingly.
If you can't change your Mark 1 stator with your eyes shut: you haven't been riding your bike enough....

#29

Offline Art

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Re: ABS newb: what do I need to know?
Reply #29 on: 30 November, 2020, 03:18:11 AM
This has to be the most feedback ever on a charging system issue, in summary

Battery voltages of 12.65 level of charge and 12.2v to 12.8v under load are good
Battery standby current draw of 0.06 mA is within Honda tolerance
RR output voltage of 13.9v at 3,000 RPM is acceptable, dropping to 13.4v at 4,000 RPM is suspect
Charging system wiring loom voltage drops of 0.15v and 0.1v between RR & battery are acceptable
Stator output voltages of 43vAC at 4,000 RPM across all three phases is good
Rectifier diodes forward and reverse bias test readings of 0.1v, OL, 0.45v and OL across all three phases are good.
RR standby current draw of 0.05mA is suspect

I'm thinking the only test not done here is the resistance between the stator coils, I'm not suggesting its necessary because we've already proved the stator is good. It may be worth your while if only to have a reference point in case of any future charging system issues. Idiots guide - Select the 200Ω range on the multimeter and test the resistance between each pairing of the three yellow output cables from the stator, three tests. Expect three equal readings between 0.1Ω and 1.0Ω.

I'm confident having spent the time in proving the good, the bad and the suspect that a replacement regulator rectifier will resolve the under charging issue. Looking forward to hearing the replacement is outputting more than 14v at 5,000 RPM and coping with the heated grips  :028:
Last Edit: 30 November, 2020, 03:31:59 AM by Art

 


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