| Scooter 996,
So many things can cause excessive amounts of fuel in the oil, including too rich a mixture, lots of short journeys, lots of slow running, some may be a problem with the bike some may be down to how its used.
I know its not the same type of engine but we used to change the oil very regularly in a turbo rallycar engine cos lots of fuel got into it. No big deal as long as you change it far more often than 6k miles.
hope this helps,
Ray | 
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