Re: CB650 charging issue

Phluge wrote:
"." <RhiannonX@xxxxxxxxx> wrote in message
news:5246e872-716f-43a3-838f-16cf0f9e6f12@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Jun 24, 7:19�am, "Phluge" <phlu...@xxxxxxxxxxxxx> wrote:

How about checking the alternator brushes before buying parts you
might not need?

OK, that will be the next thing I will do. Thanks,

If the brushes are OK, you can probably disconnect the field leads
from voltage regulator and excite the rotor field with 12 volts DC
direct from the battery and see if that raises the output voltage
while the engine is running.

The voltage regulating function of that type of regulator is just a
transistor which is
turned ON when the ignition key is ON, and then it turns OFF when
battery voltage rises above 14.5 volts.

We discussed CB650 alternators EXTENSIVELY in this group about two or
three years ago, and, AIR, the field leads are the black and white
wires. One CB650 rider e-mailed me images of the pages from his Clymer
or Chiltons manual, but I deleted them already.


I don't doubt that a bit -- from the looks of the forums I have found it
seems like every owner has had these problems, has input re: solutions, and
leaves a guy-who-can-barely-interpret-an-ohmmeter's head spinning. I have a
few pages printed out from a manual, have followed their diagnostic
instructions as close as I can figure. Here are the results I got: (I used
the 200ohms scale on a digital meter)

1.Brushes are fine -- at least 10mm above the mark. I did not try your
suggestion to excite the rotor from the battery yet, I have the oil drained
and a new filter bolt on order -- plus I'd be scared a little shitless.

2. Stator test: Continuity between all yellows is .9. Book calls for 0.5 -
1ohm. I don't understand these scales, it just says replace if there is no
continuity. Ther was no continuity with anything for the black or white
wires, none with any to ground.

3.Rotor test: It says some very low resistance should be between the slip
rings (approx. 4-6ohms). My meter jumps all over between about 10 to 175 on
the 200ohms setting -- I don't know what that is all about. There is no
continuity between rings and ground. It says that most of the time when
rotors are bad there will be either infinite resistance (burnt out) or less
than 2ohms, (meaning internally shrted.)

4.Voltage Regulator test: "With ignition on, bike not running, you should
get less than battery voltage between the black and white ires from the
regulator." I get 0.00 Volts.

4. Voltage regulator performance test: Voltmeter between + and - battery and
rev engine. Says it is supposed to prevent it from going over 14-15V, but
there is no change at all in volts at 5K rpm.

RE: the regultor/ Rectifier test: The manual makes me crazy here. It tells
you to measure between the green rectifier lead to each of the three yellow
leads in both neg and pos directions (should all be the same , HIGH or LOW
with opposites between polarities). Do they mean to measure WITHIN the
rectifier or BETWEEN the rectifier and alternator leads? Then you measure
between the red/white and the three yellows, one direction, all must be the
same either high or low -- again, within or between the alternator?

Does the fact that this bike has only 8,061 original miles give you any
clues? The brushes seem barely worn.

I'd truly appreciate any interpretation you can offer about my clumsy
attempts at measuring. The mosquitoes are out in full force day and night
and they cetainly love it that I am out there sweating. Thanks,

pflu






Just my three cents of coourse:

1) I believe one measures the rect/reg right on its terminals.
2) I still think it's best to do a dynamic test of the alternator output, if that shows healthy voltages you could probably eliminate the alternator as the problem. Lots of factory manuals say to do that even if this one doesn't.
3) Also, I was assuming the battery is good, but was just wondering if perhaps there is a blown fuse between the reg/rect and the battery?
.