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Charging Issue?

probably wouldn't hurt to replace the voltage regulator since its been there since 1983 ..... I'll keep the mechanical one for old times sake.
 
This sounds a lot like an intermittent rotor problem I had about a decade ago on my 1984 R80RT. I ended up changing over to the Omega alternator system. I liked the idea of knowing that the alternator, diode board, and regulator were all new and the extra wattage let me add extra halogen lights.
 
Not to be a wise guy

Not to be a wise guy but once you change the voltage regulator, check if you have the MOA towing or AMA rescue policy and start riding.

Chasing an intermittent problem is frustrating, can become expensive in so much as labor and replace parts and has the potential to ruin a riding season.

Best to ride until failure and deal with it when the problem is no longer "intermittent".

I spent two years chasing an intermittent system/engine cut out problem only to after a lot of labor, parts swapping/replacement, solved its self with never a smoking gun to show what of the twenty things I did actually fixed the problem.

I should have just spent the time riding, enjoying the ride and dealt with the problem when it failed and left me on the side of the road with a non intermittent problem. A non intermittent problem is a heck of a lot easier to find.

If the system is charging now, ride it and don't worry. There is always someway to get home if you break down on the side of the road.

I always carry my Anonymous book with me for start. I also have the MOA policy and the AMA policy. I have never had to use them knock on wood.

Please don't take me as a smart ass or a wise guy. I would love to write a message telling you exactly what is wrong with your bike but I can't.
I just pass on my two cents worth of experience. Ride it and enjoy it. St.
 
Hi 217Don,

There is a potential problem with how BMW mounted the diode boards on the 1983 (and other year) bikes. They used rubber vibration isolation mounts that crack and fail. When I opened up my front engine cover, the diode board was hanging by two of the four rubber mounts on my 1983 RS.

There are also issues with these mounts getting a good ground path. Should the ground path be intermittent, you will experience intermittent charging.

<a title="Rubber Mounts-One Broken" href="https://www.flickr.com/photos/brook-reams/19455468766/in/album-72157654880664060/"><img src="https://farm1.staticflickr.com/273/19455468766_168edde576_z.jpg" alt="Rubber Mounts-One Broken" width="640" height="480" /></a>
Rubber Mounts-One Broken

You can learn more about this, see how to test your diodes, and see how you can replace the rubber mounts with solid metal mounts that insure a reliable ground in this document on my site.

12 BMW 1983 R100RS Check Diode Board, Replace Rubber Mounts=

I hope this is helpful.

Best.
Brook Reams.
 
That regulator doesnt look like the mechanical one that came on my 81 R100RT. Mine was taller with a removable metal cover so you could adjust the contacts. The newer electronic ones are low profile like the one you posted.
 
"Chasing an intermittent problem is frustrating, can become expensive in so much as labor and replace parts and has the potential to ruin a riding season.

Best to ride until failure and deal with it when the problem is no longer "intermittent".

I spent two years chasing an intermittent system/engine cut out problem only to after a lot of labor, parts swapping/replacement, solved its self with never a smoking gun to show what of the twenty things I did actually fixed the problem."
.

Pretty good advice but it's hard to ride without the concern...

There could be a looming intermittent fault! My guess for that would be the rotor which I have seen have a somewhat high impedance come and go until it failed completely.

217Don came over and we took a look at the diode board, etc. All looked normal, the diode board is the Motorrad Elektrik. Brushes and springs looked fine and free. The rotor slip rings were clean.
But...the voltmeter was sticking and had some issue coming up to 14 vdc. When the bike was off, the meter sat at about 12 vdc, never dropped down to the "off" 8 volts or so. It's possible that the meter was/is faulty and the slightly dim red charging light was the sometimes normal reverse voltage you encounter when the charging voltage exceeds the battery voltage. This used to occur at high rpms going down the road with normal charging. That slight glow of the generator light was also the subject of a BMW bulletin for the K bikes which suggested adding a diode to the lamp circuit to avoid the false reading. The bulletin suggested that changing conditions could cause the light to dimly appear or not like using the heated grips in the K bike's case.
 
Hi 217Don,

There is a potential problem with how BMW mounted the diode boards on the 1983 (and other year) bikes. They used rubber vibration isolation mounts that crack and fail. When I opened up my front engine cover, the diode board was hanging by two of the four rubber mounts on my 1983 RS.

There are also issues with these mounts getting a good ground path. Should the ground path be intermittent, you will experience intermittent charging.

<a title="Rubber Mounts-One Broken" href="https://www.flickr.com/photos/brook-reams/19455468766/in/album-72157654880664060/"><img src="https://farm1.staticflickr.com/273/19455468766_168edde576_z.jpg" alt="Rubber Mounts-One Broken" width="640" height="480" /></a>
Rubber Mounts-One Broken

You can learn more about this, see how to test your diodes, and see how you can replace the rubber mounts with solid metal mounts that insure a reliable ground in this document on my site.

12 BMW 1983 R100RS Check Diode Board, Replace Rubber Mounts=

I hope this is helpful.

Best.
Brook Reams.

I noticed that you posted photos of an RS rebuild. Looks like you used vinegar and water to clean contacts and baking soda and water to stop the reaction. What proportion of vinegar to water did you find most effective? Lilewise for the baking soda and water mixture. Thanks.
 
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