bbelk wrote:Can I detect a failing rotor with an ohm meter without having to pull it from the bike?
The answer would have to be yes. By simply lifting the brushes from the slip rings you can measure the rotor for resistance (or an open) and shorts to ground. The problem, of course is that would be a static test and centrifugal force could be opening something up. But it's easy to do and better than no test and while it can show up a fault it won't prove the rotor good.
If it were me, while I had the front cover off, I would similarly evaluate the three pahases of the stator. And lastly I woull pull the diode board and check it out. Rob Frankham's test for a diode board is straightforward and easy. Plus I get confused when looking at a schematic and then trying to relate it to where to put the probes on the board itself.
And best of all it will be a good reason to put your bike on your fancy schmancy lift and smugly watch it save you labor.
Back to the rotor. Do you have a known good spare. And if not, why not?

P.S I'm going to miss you at the rally.
Ken