Fuel in engine oil

I have twin 115 hp 4 stroke, model year 2000 and I am seeing approximately 1/2 pint of fuel in the engine oil every time I change the oil. The engines only have 400 hours. Has anyone experienced this problem and what was the correction? Engine seems to run fine.
Thanks for the help.

[boats.net]

Have compression and leak down test run. It should be propped to turn close to 6000 rpm's. Check fuel pump and fuel system.