Moisture in oil?
I replaced the mechanical seal in my 1995 VN 750. I got it all back together, started, and ran it without any oil or coolant leaks.
But when I checked the oil sight glass I noticed what looks like white foam (a thin layer) on the top of the oil level.
I drained about a pint of oil, and there wasn't any indication of moisture. I guess I should have drained the whole crank case.
The bike has been in my shop since the cold weather set in, and has been in a 40º to 60º F environment.