Look for the Airhead clutch adjustment procedure in the Resources and Links thread...under General Maintenance. Making the adjustment to be "just shy", etc., might be what's causing the noise. In addition, under real engine load, once the clutch has been separated, the clutch disk is supposed to float on the tranny input shaft. In the non-running situation, there's nothing to make the plate float or move around on the splines. So, it could be rubbing just because it hasn't moved yet. I'm sure you did grease the input splines...