Boxerworks.com

84 R100: Well.... while I've got things apart, maybe it's a good time to run some extra grounds. Anyone have instructions on the best way to do this? I've got some new battery cables to install as well. If the original ones look good.....should I change them anyway?

Snowbum mentions a wiring "spider" that connects several places in the timing chest to improve grounding. It's on this page:

http://bmwmotorcycletech.info/diodebds&grdgwires.htm

Look for the section starting "The grounding wires assemblies are a story in themselves". I wish he had a picture...I installed one of these many years ago. I got the harness from Motorrad Elektrik but don't see it offered on their website.

It looks like in the end, that if you're using the solid diode board mounts, the extra ground harness may not be needed.

Kurt in S.A.

As I recall, the trick was to have grounding go directly to the battery negative terminal rather than through the engine/transmission block .
Mine was an '87 RS.
There was a grounding terminal on the frame centre rail under the tank. Diode ground went to that, then a heavy wire (12 gauge I think) went to the battery.

Very interesting!

I have a kit from Motorrad Elektrik I bought a few years ago. I'll make a survey of connections condition.