R27 Charging Problem

[comet]

I would not start the engine until I looked at the generator. Check for loosness and rubbing of the armature to stator. While in there check the timing chain and hope that's the rubbing noise. Good Luck.......Comet

[Allan.Atherton]

... the charging light will not go out and actually pulsates in synch with the engine RPM. ... In addition, there is a kind of rubbing sound coming from the generator area...
I had a new R27 generator do the same thing about a year after installation in 2003. Pulsing means loss of polarity. They say this can only be caused by a bad ground. Could be in the headlight terminal board where you worked, or in the generator wires, or in the generator (the rubbing), or the ground wire from the transmission to the rear terminal board. Check all that.

You can repolarize the R27 by connecting for a second the two terminals on the regulator:
Front Blue D+ 61 and Rear Red B+ 30/1
Or Front Blue D+ 61 and B+ on the battery
I used a 3' length of insulated copper house wiring with 1/4" of insulation stripped from each end. Just touch the wire to the second point long enough for one good strong spark.

I was never able to find my problem. The red light was OK until the headlight was turned on. Then if the rpms dropped to idle, the pulsing would start again and the generator had to repolarized. So I had to quit using the headlight, or face repolarising at every stop sign. I resorted to making a repolarizing switch from a horn button to use while riding. Eventually I installed a home-built 12V system and sent the 6V generator to Motorrad Electrik for diagnosis. He found nothing wrong but theorized a winding might intermittently open.

I have more detail but probably too much for the forum; can email it if you need.

[R.D. Green]

Thanks, Allan. I appreciate the info. Let me get into it and I'll get back to you if needed.

The only reason I even had to mess with the headlight pod wiring was because the previous owner had gotten a new chrome switch cover and rain protector (slide) and had never installed it, among many other things. When I got the bike he had installed a toggle switch for a simple on/off ignition switch and the original switch parts were in a little box. I re-used them all and they seem fine. I never had to do anything to the original switchplate as it was completely wired already. He had simply dis-mounted it and left it dangling. All the wiring to the generator appears to be completely unmolested and untouched. Even the center bolt from the armature does not appear to have been touched since the factory. It's curious that the problem coincides with the switch re-installation but the rubbing sound is brand new and leads me to believe the generator itself has a mechanical problem.

Richard

[Allan.Atherton]

... the rubbing sound is brand new and leads me to believe the generator itself has a mechanical problem.
Rick Jones of Motorrad Electrik returned my almost new R27 generator with this comment:

I found no detectable fault with these parts. But, it appears that the armature has been making light contact witht the field coil of the poles. The armature laminations appear to have shifted slightly, and this may have pinched the windings internally, might be reacting to motion and shorting.

So, if you are hearing a rubbing sound from your generator, your generator may have what mine had, a loose lamination, only so loose it rubs loudly. Mine never made a sound.

[VBMWMO]

Got the electrics all back together and went to take the R27 out for a "real" ride the other day, as opposed to just pooping around the neighborhood as I gradually got the bike sorted out. She started up fine but now there's another problem which appeared out of the blue and with no warning whatsoever.

The electrical system is not charging - - the charging light will not go out and actually pulsates in synch with the engine RPM. By "pulsate" I mean that it pulsates from lit to very bright. It never goes completely out. In addition, there is a kind of rubbing sound coming from the generator area which sounds like it could be a bearing of some sort. This sound also appeared very suddenly.

Generator brushes and springs are fine. I'm sure this has nothing to do with it, but it seems coincidental that this problem appeared immediately after I re-installed the ignition/light switch and switchplate.

Any advice before I start getting into the generator?

Richard

[mikebarker]

Hi, can anyone tell me what voltage reading should be on the blue feed wire going to terminal 61 on the gen with ignition on but without the motor running?

[schrader7032]

I'm bad at these sorts of things, but terminal 61 feeds the generator light. One side of the light represents the battery voltage and the other side represents the generator voltage. If the voltages from the battery and generator are essentially the same, there is no voltage drop and the light is out. The light illuminates when one side of the light is less than the other side. It appears that the other end of the wire at terminal 61 is associated with generator output (D+), so if the key is on but engine not running, I would think that terminal 61 would see 0v and the light should light assuming the battery is healthy.

Next time I stay at a Holiday Inn Express, maybe I'll have a better answer!

[sminn560sl]

This may sound like a dumb question but is there any chance that you reversed the polarity on the battery leads? Believe it or not I've seen it done.

[mikebarker]

Thanks to both yourself and Kurt for your replies.
~~~~~~~~~
Update, Silke and the guys at Rabenbauer GmbH got it spot on, After an email to them this morning they came back and sed that the field windings had been fitted wrong and the polarities were at a miss match between the 4 winding and they were absolutely spot on and I had messed up on one coil. rather than the wiring being -0~0~0~0- like a snake between the coils I'd ended up -0~0~0u0- a bit like a snake that had ended up as roadkill.

NOT BAD for just ONE email

Thanks again Mike B.

[schrader7032]

Not sure I understand, but glad you found the solution!