Check the blow-by catch bottle, beneath the seat. It has a drain tube, with a plug, hanging down. Drain that first. If that is not the source of your problem, take a look at the carbs, and see if they are full of oil and gunk (if so, they need to be pulled, disassembled, and cleaned).
Water will boil off of the oil if it reaches 212 F, but it has to reach 212 F, or higher, not 180 F. If you are concerned about it, of course, you can simply change it. As to other possible sources, it could be caused by taking short trips which never fully warm up the oil: water is a normal byproduct of combustion, which is why short trips can be quite hard on engines. Good luck.
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII