[bombermanx]

Maybe I should added that I rode 3-4 times each winter, that's why I didn't want to go whole storage procedure written on my manual. And oil traps the moisture? How can it happen? Can you explain?

Air in the crank case condenses and forms water droplets mix in with the oil, much like putting a lid on a glass of hot water, when the water cools, the lid will have condensation on it too. The next time you run the engine for 5 minutes, the oil is not hot enough to boil off the water, and the oil/water mix gets pumped throughout the engine. When the engine is shut off, hot air condenses and form water droplets again as it cools and it goes around again.