Voltmeter recently started showing that my new battery wasn't charging fully and actually lost voltage slowly over 30-40 mile ride. The charging guide led me through a logical, step-by-step diagnosis that narrowed in on the rotor. It ohm'd out in the low-to-mid 2's on my digital multi-range meter on the 200 ohm scale. Installed new Racetech rotor tonight, started her up and all looks good - the voltmeter needle climbs toward 14 as it should. I didn't want to run it long enough in the garage to warm it up enough to buzz up to 3500 rpm and too late tonight for a test drive, so tomorrow will tell the tale. The charging guide was really helpful - I couldn't have found the issue myself without it, so thanks to all who wrote and illustrated it!