Tach needle jumping around...

[JonnyO]

Maybe the trickle charger has eventually done something not good? Battery shows 13.18 after unplugging charger and revs up to 14.81 on choke.

[JonnyO]

15 sounds a bit too high, are you running a lithium battery? I'd be leery of anything higher than about 14.4 with a lead-acid battery.

The tach itself is reading off one of the stator windings which would be an AC voltage somewhere in the 50v+ range.

I don't believe so. Just an Interstate. I don't think they list a lithium for an XS. I've had it for a couple of years.

[LAB3]

LAB3, no offense intended by my previous post, just factual knowledge.

None taken. After living over 20 years with an off grid power system running 12v lead acid batteries I have a good bit of charging system experience myself. Anything over 14.2 would be suspect in that scenario although I've seen people bump that set point up a bit to 14.4 with AGM.

[motoman]

LAB3, no offense intended by my previous post, just factual knowledge.

[motoman]

15 sounds a bit too high, are you running a lithium battery? I'd be leery of anything higher than about 14.4 with a lead-acid battery.

The tach itself is reading off one of the stator windings which would be an AC voltage somewhere in the 50v+ range.

Actually LAB3, A lead acid wet cell battery on a 12V system, the regulated voltage with system running and working correctly, regulated voltage correctly should show to be 13.8-14.2volts. That comes from having 50+yrs. experience diagnosing 12v d.c. elecrical systems in the automotive world. That may also be of help to many others here.

[bikerphil]

Well Jonny, it looks like either obtain another tach and try it, or continue going through the wiring, cleaning all related connectors. At this point it could be either or maybe even something else. Operating on a tamper proof tach might not be for you. It's an extremely finicky task.

[cajun31]

The only time I ever saw mine go up to 15 plus is when my voltage regulator was bad. I honestly can't remember what my tach was doing though. I replaced the voltage regulator and everything went back to normal.

[LAB3]

15 sounds a bit too high, are you running a lithium battery? I'd be leery of anything higher than about 14.4 with a lead-acid battery.

The tach itself is reading off one of the stator windings which would be an AC voltage somewhere in the 50v+ range.

[JonnyO]

Sounds about right!

Maybe the tach is just no good. Still puzzled. Mechanic buddy said to put voltmeter switch at 20. I did-Idle at around 12.36 revs up to 15ish.

[LAB3]

Sounds about right!

[JonnyO]

To illustrate the depth of my mechanica skilz and expertise, when I reinstalled the lights back in the tach I had the high-beam and neutral switched... which I found out only after putting it and half fairing back on the bike and going for a quick ride to see if that had magically repaired the problem. Of course it hadn't. lmao Perhaps I should have checked before fully assembling it.
I'm going to see if I can find a coloring book with pictures.
Gonna look up how to use my voltmeter to test the alternator output from the battery. Huh. I wonder if the car battery tester I have ( somewhere ) would test the bike's alternator as it will on cars..?
Have an appointment at the VA, in an hour, and a bunch of errands to do but will test it as you suggested when I'm done.
Thanks again.
Merry Christmas to all.
HE LIVES!!!

Well, if I used the meter properly, it went from around 11 to 14.6 when I revved it.

[JonnyO]

There is no cable driving the tach, it gets it's signal from the alternator. I suspect that maybe the connector plug behind the fuse panel may be the culprit. Before you go digging for it, with the bike running, check your alternator voltage output with a meter at the battery terminals. When you rev the throttle, you should see a decent increase in voltage, 13V+. If it isn't increasing, then I would check that connector for it being melted.

To illustrate the depth of my mechanica skilz and expertise, when I reinstalled the lights back in the tach I had the high-beam and neutral switched... which I found out only after putting it and half fairing back on the bike and going for a quick ride to see if that had magically repaired the problem. Of course it hadn't. lmao Perhaps I should have checked before fully assembling it.
I'm going to see if I can find a coloring book with pictures.
Gonna look up how to use my voltmeter to test the alternator output from the battery. Huh. I wonder if the car battery tester I have ( somewhere ) would test the bike's alternator as it will on cars..?
Have an appointment at the VA, in an hour, and a bunch of errands to do but will test it as you suggested when I'm done.
Thanks again.
Merry Christmas to all.
HE LIVES!!!

[JonnyO]

This maintenance tech tip might help with what Phil is telling you to do. Charging System/Tachometer - XS11.club Forums

TY! That should answer my next question without having to ask.

[cajun31]

This maintenance tech tip might help with what Phil is telling you to do. Charging System/Tachometer - XS11.club Forums

[bikerphil]

Do like I suggested before, check your charging system voltage with a meter. The alternator supplies a signal to the tach. If the signal is flakey, you'll have a tach malfunction.