Testing VR and stator health

[34nineteen]

I'd still pull the inspection hole and take a sniff. If it smells burned in there, that could be an indicator that you are having stator issues. Primary oil is getting splashed all over the stator, and if its burned you'll know. Its a one minute inspection and could be a game changer.

Also, like Lunatic said, if you are running certain primary oils... I do remember reading somewhere that someone's fancy oil wound up compromising the epoxy on the stator which lead to problems.

Hopefully, the carbon frame covers are on your bike for looks! :upset:

 

[njloco]

Fancy oil ! What fancy oil ?

 

[Mesozoic]

I will check the primary oil tonight. I'll have to Google what the best oil to use in a Buell primary is... as I'm sure that's been beaten to death. I'm currently running Belray Sport Trans fluid.

Regarding the frame covers, they're unfortunately not just there for looks. I supermanned off my bike back in '15 and the bike went down on the left side. The wreck resulted in a dent in the puck area of the frame. I contacted EBR and they graciously looked at my photos and suggested that it was more or less superficial - and to leave it alone. So I had a local shop install the Speed-of-Color frame covers for me, as well as new pucks to not just cover up the dent, but provide additional protection. :black_eyed:

 

[34nineteen]

Stuff happens. Hopefully the bike took the brunt of the hit and not you.

Not to get into an oil war, but it seems that Amsoil and Harley fluid seem to be popular. You may want to do a google search for an article about oil damaging stators.

 

[LazyZ]

I have some confusing results from testing my stator (following the instructions in the Buell electrical diagnostic manual).

• The 1st check involves checking for continuity between ground and either of the stator leads. I have continuity between ground and both of my stator leads, which according to the manual "indicates a grounded stator which must be replaced."
• The 2nd check is measuring resistance across both stator leads. My measurements fall within the 0.1-0.3 ohm spec, which is a bit unusual considering they're also continuous with ground.
• 3rd check I performed was a direct stator AC output check. I'm seeing 30V at idle and 55V at 2000 RPM, which generally indicates solid functionality.

I'm a bit confused as to why the stator would be generating any voltage if it was shorted, but almost all of my experience has been with DC circuits, so maybe I'm missing something here.

The Buell manual states that if the AC output of the stator is good (which it is), the charging problem might be a faulty regulator. So I started going down that rabbit hole. I performed a milliampere draw test. I used 2 good meters to verify this and came up with a static 24.63 mA draw with the bike just sitting there with the key off, which is significantly over the max 2.0 mA spec. If I disconnect the regulator from the circuit, the draw drops down to 1.12 mA, which is much better. I would've thought that this meant that the VR's static draw is too high, but according to the manual's charging system troubleshooting tree, this indicates "replace grounded stator."

So... would anyone like to confirm that this is indeed the case? Perhaps someone with a similar experience? I should mention that my issues began a few days after I installed the Buell heated grips kit. LOL

- Your stator is just one long wire. If this wire is not broken and if it is shortened on the ground anywhere your tester will show continuity on both pins of the stator plug.

- If stator is shortened on the ground in one small area or in one spot and if the stator coils are not shortened between each other and if the stator wire is not damaged you will see normal healthy stator resistance between stator pins 0.1-0.3 ohm.

- If stator shortened on the ground in one spot or in one small area it will generate AC voltage as usual.


In your case the stator coils wire or stator lids have somewhere shortage to the motorcycle ground. It means it will not work properly because of now your alternator circuit has connection between the stator wire and battery negative terminal.

You already found at least one issue. You can not test VR with such stator malfunction because of you will have false readings. Fix the stator first and then proceed with another tests if it will be necessary.

Inspect the stator lids from stator plug and up to the stator grommet. If you see no any damaged wires open the primary cover and inspect the stator lids inside the primary case. If you see scuffed wire shorten on the ground, fix it. If you see no damage on the stator lids the shortage is likely on the coils, probably stator wire shortened somewhere to the stator housing. If so you will likely will not be able to fix it easy and in this case you have to replace the stator.


If stator shortened to the ground in one area and no stator coils are shortened the stator oil will smell as usual, no burned coils or anything.

One trick you can do prior digging in to the primary case - measure resistance between each pin of the stator plug and motorcycle ground. If the resistance between first pin and ground and resistance between second pin and ground are pretty different you are probably lucky and shortage spot is probably somewhere on the stator lid (the one with lower resistance) and you should be able to fix it if you can find it. If the resistances are about the same the shortage spot is likely somewhere in the stator coils and the only reasonable way to fix it is to replace the stator.

 

[Mesozoic]

As a final check and because I didn't trust my DMMs, I grabbed a GWInstek GDM-461 DMM from the office. With that meter I'm seeing 0.3 ohms between the stator pins. I'm seeing 2.5 ohms between each stator pin and ground. So, I guess I'll start by replacing the stator. Thanks for all the feedback! I'll post my results as I fix 'er up.

 

[Mesozoic]

Man, I am slow to getting around to repairing things. I've been riding my 1125CR to work and back for months now, but as it's approaching its 24,000 mile engine overhaul (I jest, but it really isn't a fun job) I've started looking at the XB12 closer.

So I pulled the primary cover and drained the fluid... wow, it was quite smelly. Definitely burnt. Pulled the stator out and found this:


You might able to see that the posts at 5 and 7 o'clock are burnt to a crisp. I'll chuck the new one in there tomorrow - if anyone has any pro tips for this job, please let me know!

 

[Outlaw]

Very crispy. Good diag Meso

 

[Mesozoic]

Very crispy. Good diag Meso

Extra crispy, for sure. Thank you all for the helpful replies in guiding me through the diag and sorry about the "keyboard slugfest." :black_eyed:

Let's see if I can get the new stator installed with the correct rotor clearance and working properly again. Is it really necessary to replace the stator mounting bolts? I was thinking of cleaning them up really good and putting fresh Loctite on them, but the service manual says NO.

 

[Mesozoic]

Machine is back on the road again, using Amsoil 20W50 synthetic motor oil in the primary. Seems happy and definitely charging.