Burnt out stator and testing regulator

[Beebop]

Good day gents, and a prosperous new year to all.
In November, after hitting an unavoidable pothole, The CEL came on and the motor almost died. I managed to nurse it to a
fuel station about 2km further on, but then it would not turn over and gave symptoms of a dead battery. When I treid
to jump start, I saw smoke coming out from the wiring loom under the seat (2006 XB9SX 50000km) . I found that the
loom had chaffed through against the seat lock and shorted one of the wires. I moved it away, jump started and rode home.
The battery was toast so I replaced it, then found the stator had burnt to earth as well, so I had that rewound. I openned up the
loom and found only the one wire damaged, which I repaired and wrapped. All was running
fine for a month or so, and now on Sunday , it wouldnt start again. Battery was low, so out with the multi meter. I found that at
idle it was only chargeing at 11V, and at 3000 it was the same. I tested the stator and found again its shorted to earth.
The possibility exists that the regulator has been damaged and is now causing the stator to burn out.
Is there any way to test the regulator before I go and replace the stator and possibly damage it again. This can become an
expensive game.
Thanks for all the generous help offered on this forum.

[LouWambsganss]

Disconnect the stator and check the output AC voltage directly. It should be about 20V AC for each 1,000 RPM (give or take, but that's the general idea). Also ensure that no stator wires are shorted to ground (earth). If it is good, then you may have either a wiring problem or regulator problem. The Stator and Regulator connectors are known failure points. Check them for signs of burning and replace with newer style if necessary.

[user_deleted]

battery must be fully charged with a "real" charger.....not a tender....to properly perform the VR and stator tests. simple VR ohm tests in service manual. your 2006 is a 3-phase stator/alternator and here's the test:
AC Output Check
1. Test AC output.
a. Locate voltage regulator connector [46] under
sprocket cover. See 7.25 SPROCKET COVER WIRING.
Disconnect from alternator stator wiring.
b. Connect an AC voltmeter across stator sockets 1-2.
c. Run the engine at 2000 RPM. The AC output should
be 32-40 volts AC. (approximately 16-20 volts per
1000 RPM).
d. Repeat test across stator sockets 2-3 and 1-3.

lastly be absolutely certain the charging system harness connector (#77 connector) behind the front plastic sprocket cover is in perfect shape. if questionable repair same on your own or purchase the dealer up-grade repair kit which is still available.
your VR part # for 3-phase system is Y1302.028

[Beebop]

Thanks guys. The stator is definitely faulty, or at least there is a short to earth from the plug to the stator when disconnected.
My main concern is the state of the regulator, is there anyway to test it on its own ??
Lunaticfringe, I did check that plug out the first time, and again now, and its in perfect shape.

[LouWambsganss]

Once you install a known good stator, you can connect it to the regulator, but leave the regulator disconnected from the battery. Check output DC Voltage. With no load, it should have no trouble maintaining over 14 VDC. There's not really a good way to statically test all of the shunt bridge rectifier circuits in the regulator. If you really want to dig deep, you can build a testing rig (such as this http://www.edaboard.com/thread327627.html) but that is a lot of detailed work. A brand new regulator is not terribly expensive. You can also install a universal MOSFET replacement regulator (Shendingen is good) if you want. They generate less heat than the stock shunt type, but they do the same job overall.

[Beebop]

So to get back to this thread.
After replacing the stator, I tested the charging voltage at around 14,6V at the battery, so all good
Used the bike for a few weeks and then one day it wouldnt start again. Checked it all through , and
the stator had burnt again.
What am I missing ? I've done a bench test on the regulator as far as I can, tested the charging voltage
when running. What else should I be checking ?

[user_deleted]

the stock 3-phase 2003-2007 stator assembly is factory part # 29971-02Y. the superseded replacement is same number with suffix A. is that the one you purchased or not?
not to dazzle or baffle you with techno jibberish but the 3-phase "shunts" excess voltage to ground when the VR tells it to. these stators run "hot". as previously mentioned your entire wiring loom must be flawless or stator failure results. are you sure on yours????
1- see the link below. easier to view the pics than have me try and describe the clearance issues. see if this issue exists with your installation.
2-OEM stators come with warranty. there was a faulty batch of replacements floating around back in the day being approx. 10 years ago or so. have the dealer warranty yours.
3-if it were me and i was ABSOLUTELY CERTAIN the installation was performed correctly and this happened again i'd switch over to the Accel 3-phase 38 amp replacement. lifetime warranty and priced right.
NOTE: i've owned approx. 25 buell XB's to date with accrued mileage well over 100,000 miles without a single stator failure. simply put you have a wiring or rotor problem.

http://www.badweatherbikers.com/buel...tml?1477005505

[GregoXB]

Interesting. I never heard of those stator clearance issues. If he did not check for clearance when installing and that happened, post install while riding, would he know immediately?

[Cooter]

Not until the stator wires got grounded or worn through making an open in that leg. Could be right away, might take awhile.

I'm totally with Lunatic on this one. A super rare problem back to back? I guess it's possible, but I'd also look for issues elsewhere.

How exactly are you testing the stator and what exactly are the results?

[Beebop]

Ok the "new" stator, was a rewound one. This is South Africa, where these parts are not readily available.
The test although not necessary since you could physically see the burnt wires, showed short to earth.
I tested the regulator with a standard diode test on the input wires. Not much else I could find in the way
of testing. The keeper is the original, and showed no evidence of interference with the rotor bolts.