Checking voltage regulator on an '08-09 Lightning XB9SX

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12-17-2019, 04:58 AM
Endopotential

Checking voltage regulator on an '08-09 Lightning XB9SX

Hi guys,

Looks like it was my turn to have my VR burn out, but just wanted to double check before I buy a replacement.

My bike died on weekend ride. Jump started it at a friendly fire station, but bike died again after one block. The little LED voltage meter I installed in my dash showed a quick drop from 11.5 down to 5V, at which point bike cut out.

Battery charged on tender back at home goes up to 12.5V, bike starts fine. But revving it up does not increase voltage at battery terminals.

I checked out a lot of threads on troubleshooting stators and VR, but most of them reference older models where everything is on the right/sprocket side of the bike.

The '08-09 got the updated VR I believe, and everything is hidden under the left side air scoop? I went through this long thread here https://www.buellxb.com/forum/showth...ator-or-Stator

Essentially, with the grey 2 prong connection from the stator to the VR I get no shortage between the holes. I get about 30V AC at idle, going up to about 50V at 2500rpm. So this makes me think the stator is OK.

Any way to check on VR function? That last thread debated checking DC voltage on the black 2 prong connection exiting the VR, where I only get 4-5V. Is this the proper diagnosis of a dead VR? The unit itself and cables connected to it look fine.

And the best replacement is still OEM Buell Y0302.5A8 (L19D)? Any better options out there?
12-17-2019, 03:06 PM
user_deleted

And the best replacement is still OEM Buell Y0302.5A8 (L19D)?
YES

Any better options out there?
not without a ridiculous amount of unnecessary work involved.

DAVID:
1-invest in a quality 12 volt charger with at least 6 amp steady-rate output capacity. the higher the better. a life-time investment and these lead-acid/AGM batteries suffer extensively when being brought back up to full steady-state static voltage with a POS tender.
2-you've been on here long enough to know the "check cables and battery fuse for corrosion" drill....but your stator is fine----your VR is on death-row.
13.5-14.7 volts DC at approx. 2500-3000rpm with no drop-outs or spikes is the proper range. doubt you have that.
12-17-2019, 03:09 PM
Cooter

Yes, X 1000

Whoever this Lunatic guy is ^^^, he sure knows his stuff;)
12-17-2019, 07:11 PM
Endopotential

Thanks, you guys are the best! Happy Holidays!
01-08-2020, 03:32 AM
Endopotential

I got the specified VR from St Paul Harley, and installed it with some of the recommended spacers on the back.

Good news - the bike runs well now, charging 14-14.5 volts at the battery terminals at idle

Weird stuff - on initial startup, there is a high pitched whirring/buzz from the VR that lasts 10 seconds then the noise shuts off. I checked all the bolts, nothing loose nor rattling.
Stop the motor, start again, and silence.
But wait 10 minutes or so, start the bike again and that whirring noise comes back briefly.

Hopefully you can hear the buzz over the engine noise
https://www.youtube.com/watch?v=q1jh...ature=youtu.be

Unless you guys tell me otherwise, I'm worried I got a defective unit.
Will try to call St Paul tomorrow to see what it takes to get a replacement.
02-02-2020, 10:59 AM
Captbrad88

I can’t get my crank nut off to replace my stator. Has anyone come across this? I’ve actually broke my drive chain putting so much force on the wedge with a 5’ pipe and still nothing. Should I try and apply heat to get it loose? 2009 xb12
02-02-2020, 03:01 PM
Cooter

Quote:

Originally Posted by Captbrad88

I can’t get my crank nut off to replace my stator. Has anyone come across this? I’ve actually broke my drive chain putting so much force on the wedge with a 5’ pipe and still nothing. Should I try and apply heat to get it loose? 2009 xb12

Oh NO! Please, please, please get the FREE manual download from Buellmods.com or Buelltooth.com.

Do the procedure as the manual specifies, just as it is written, INCLUDING THE SPECIALTY TOOL. It will help you avoid damaging the motorcycles primary chain and transmission if you haven't already.
02-02-2020, 05:06 PM
Endopotential

Quote:

Originally Posted by lunaticfringe

has this been resolved? common courtesy dictates taking a minute to report results/findings as it helps other board members.

Woops sorry, my bad, John.

Yes happy to report that the new VR fixed the bike right up. I wrote on a parallel thread about how I should have believed my dash voltage display, when it would randomly jump around 11-14V when riding. Took it out for a nice long ride yesterday in warm California sunshine, and the bike was a fun as ever.

The noise turned out to be a bit of stupidity on my part. While waiting for the replacement VR, I was modding the clutch ramp to decrease the handlebar pressure. The new part was scraping on the clutch pack and making the horrible racket, nothing related to the VR.