Boxerworks.com

I fought this for 6 months on my 92 R100R. Cleaned and greased all connections, checked dash bulg connection, replaced diode board (got better but light still on at higher rpms) changed regulator, checked bushes, tested rotor, all good. While checking rotor noticed cracked wire at stator connection, resoldered it, problem solved.

I agree with Dan in Il. Both my bikes had the same symptoms and both were fixed with new brushes.

To make things easier, you really don’t need to mark all the wires before removing the stator. Just make sure when you put it back together that you don’t cross the 2 wires going to the brushes. One goes to ground, so they’re easy to figure out. It doesn’t matter what sequence the three 3-phase wires go in, so you can’t mess that up.

I took the day off and rode out to a friends place by the lake. He works on everything airhead and keeps a fair-sized inventory of this and that. When the bike cooled down, I pulled the stator. Needless to say, it was a grimey mess inside. I cleaned and buffed up the inner guts. Same with the stator which checked out ok. The brushes, according to Les, were toast. I replaced with new, put it all back together to no avail. I put in a new diode board. That fixed it.
Yahooo!
Thanks for the help here, guys.