Did you drain the oil into a glass container as was suggested 8 posts back to determine if you are getting water or gas in the oil?
Unless you are a pretty handy mechanic, the cure is going to be to have a shop fix it anyway. We've given you the two only probabilities.
The longer you run that motor with diluted oil, the closer you get to a repower.
2015 Seaark 1872 MV CC
Etec 90 HP
Bitter Gun Owner