F250 oil outside carburetor

[lbc_robalo]

2017 F250 - (150 hrs)

I noticed some smoke coming from the engine.. (I ran it for at about 25-30 knots for about 10-15 min) Not a lot of smoke, but a little bit of darker smoke none the less. The engine is fairly new and the only thing I noticed was the plastic cover above the carburetor had oil residue on it. I noticed a little bit of oil around the outer ring of the carburetor. I'm not a boat mechanic but I believe this is the issue causing the smoke. Just curious if this a serious issue or what may have caused this? After returning to the dock I idled it and didn't see any more smoke.

Thanks in advance for the help.

[99yam40]

on a 4 stroke, I would guess blow by of the piston/rings pushing oil mist out of crankcase into the intake cover so the motor can burn it
a leak down test would be good to see how much leakage it has and where