The Gurus were right again!

[Guest]

Gurus as in our good buds Ed (Nessim) and Steve.

I 've been kvetching for the last few days about what I believed to be a wonky stator causing me to be over charging. The tests I performed showed the R/R to be more or less up to spec but the stator was doing weird things as in jumping about from 25 or 30 volts to as much as 140 volts. I naturally assumed it was bad. As the PO had just changed the R/R prior to putting the bike into hybernation 3 years ago my too quick to jump to conclusion brain decided that must have been due to the stator being toast.

Not so fast says Ed. Not so fast says Steve. Ed says it can't be the stator, notwithstanding the apparent wonky voltages as the bike is charging. Enough voltage is going to the R/r but its not dealing with it very well. Steve says your multimeter is not making good contact with the stator legs and or you maybe unconciously moving the leads as you try to take the reading. Doubtful thinks I but I'm willing to do some more tests.

Good thing I did as it saved a stator transplant. I did switch in the Shindengen R/R from the parts bike. With the sense wire to the battery positive pole I get a nice 14.8v at 5000 and a constant 13.25 at idle. Good enough for government work I think.

Well since the R/r seems to be doing its job lets look at the stator A/c voltage. As I'm looking at the disconnected bullet conectors it hits me. I hadn't pulled back the insulators and that had given me difficulty getting the probes to make good contact. Pull back the insulation and viola I got 30 volts at idle rising to 80 at 5000. The contacts were a tad dirty too so they're taking a dip in jewelry cleaner as we speak.

So very big thanks to the Gurus and everyone who chimed in you've saved my bacon one more time.

I'll be raising my root beer glass to you at dinner tonight.Thanks guys.
Spyug

[JEEPRUSTY]

Why the heck didn't you swap RRs first thing?
Ahh because you folled youself into thinking the problem had to be in the stator!

There is a psych term for this phenomenon Though memory fails me.
Sort of like losing keys in your hands and some such but not exactly.

[OldVet66]

I'm guessing the R/R was generating Electrical noise that was throwing your electronic meters on their ear. Those previous readings were not to be trusted.

[spyug]

I'm guessing the R/R was generating Electrical noise that was throwing your electronic meters on their ear

I'd say you were correct and the sad thing is I seem to recall I noted a similar incident when I first got the bike and that time I put it down to the multimeter. I trashed it thinking it was toast since my backup meter, at the time, didn't register the same way and showed the R/r to be putting out proper voltage. Dumb on my part.

Ahh because you folled youself into thinking the problem had to be in the stator!

Yup, I guess I did sort of. I did actually switch to the other R/r but didn't (for whatever reason) have the sense wire hooked to the battery. I was getting the same voltages so I figured it performing the same as the stock one therefor if two showed the same voltages, they couldn't both be bad so it had to be the stator. Amazing what your brain can trick you into. That's why I'm not a scientist or engineer. I like to think I'm open and analytical but I guess I'm not so much.

I'll have to change my way of thinking. Tough to do at this late age

Cheers,
spyug

[OldVet66]

I'll have to change my way of thinking. Tough to do at this late age

Never too old, and thinking out of the box keeps you sharp.

[Gibbelstein]

@Jeeprusty: The phenomenon you're thinking of is the confirmation bias. You only pay attention to information that supports your current opinion/theory/guess/world view. For more examples of this, see any "political" post in the Off-topic area. =)

I'll remember this moment when I mail my student loan payment this month...