Voltage issues

[tweeleft]

Questions about voltage across the battery. At idle meter reads 13.9. I have a tach wobble at 2 to 4k. Rev motor meter goes to 15+ volts. No voltage change turning signals or hi beams on at idle. She does not run out good when riding. I've been though timing,sync carbs,air cleaner,auto cam chain tensoiner . She's a 79 SF

[BA80]

What are you experiencing when riding?

[ddragon63]

Sounds like its over-charging to me... should only be a little above 14 when alternator is excited. Possible voltage regulator spiking.... I'm sure someone more knowledgeable than me can chime in here. If it was a car I would suspect the volt reg every time for overcharge.

[crazy steve]

Sounds like your voltage regulator is TU.... It would appear to be giving full output at all times (not 'regulating'), as you should have about 13.1V at idle and around 14V at 2000+ rpm. There is a test procedure in the manual to check the regulator. You need to get that fixed, as it's very hard on the components and the battery.

[BA80]

Yeah, the voltage seems a little high but that shouldn't make it not run well Don. That could just be the meter he's using.

Is the meter your using analog or digital tw?

[ddragon63]

Sounds like your voltage regulator is TU.... It would appear to be giving full output at all times (not 'regulating'), as you should have about 13.1V at idle and around 14V at 2000+ rpm. There is a test procedure in the manual to check the regulator. You need to get that fixed, as it's very hard on the components and the battery.

a Don's right about the Reg would have been ok with me Steve

I would assume the high voltage is spiking the ignition system and causing it to run like doo doo....

[TopCatGr58]

That voltage does sound a bit Xsive at idle, the charging system is lucky to generate above 12 volts at idle!! Geezer makes a Reg/Rect that uses stronger components and does provide a stronger charging signal at idle. Are you sure your voltmeter is reading correctly??

The reg/rect may Not be seeing a clean voltage level due to corrosion and such, and so it may be activating/triggering the coil earlier to get the voltage up since it's possibly not seeing as much voltage as what may really be there,
but again, the XS's charging system just can't make much power at idle speed anyways! The book/manual test states at least 2500 rpm is needed to reach max alt output!!

Would still recommend cleaning the electrical contacts, the wires at the reg/rect housing, it's connection to the frame and such. Then retest the voltages. Perhaps get some new alkaline 1.5 volt batteries and put them in series to test the voltmeter!?

T.C.

[cywelchjr]

Now I don't know these ignition systems as well as Davinci/Randy, but some electronic ignition systems don't like the voltage to be high and don't work quite right when it is. I don't know if that's the case here, but with voltage that high there is the possibility of damaging components and that needs to be fixed before going any further, or at least making sure that the readings are accurate. You CAN get the voltage that high at idle if you short the grounded side of the field coil, so those numbers are possible and should be verified.

[tweeleft]

My meter is digital set on dcv I have another one I'll try tomorrow. As far as running while riding, sputters when twisting quick until about 4500 r's after tach wobble, smooth at slow twist of the grip

[BA80]

The tach problem may or may not be a symptom of the problem. It runs off alternator pulses so if there is an alternator problem it could be part of it.

Whenever anyone talks of a sputter the first thing that always comes to mind for me is pickup coils. I fought thet problem for quite a while with my XS before I accidentally stumbled on the PU coil wires making intermittent contact.

Have you cleaned or rebuilt the carbs?

[tweeleft]

I checked my meters they are .1 volts off from each other. I used the higher of the two to get the readings I got. I'll do more tomorrow. Check ohms reading by the book(manual) thx guys I'll post more tomorrow

[skids]

At idle, since your charging system would put out less volts than the battery, you should be reading about the same as the battery's charge. In fact you should see the voltage gradually drop if you hold the idle speed...

[tweeleft]

Hey Thanks Guys. I pulled the voltage regulator and tested it on and off the bike as per manual. The regulator side is shorted. the diodes are good. Has anyone used the Accell regulators, I found them for half the price of greezers (can't aford the $125) like to get his thou. Not sure even when I can aford the Accells

[cywelchjr]

Shop around and take a chance on a used one. I put a used one on mine over two years ago and it still works like new. I found one for $15, don't know if you can find that good of a deal, but you might come close on a used unit. IIRC there IS a way to roll your own as well, but that might actually cost you more.

[Elevener]

Check with Andreas for one