The drain port on the pan is on the front, and not really on the bottom. A drain from there leaves a few ounces in, which may be water. That's why I recommend taking off the dipstick tube and sucking from there. Just one 10mm screw holds it in, super easy. Stick a 1/4" tube in an see if any water comes out when suctioned.
Then after some running, open oil fill cap and see if rockers have any milkiness there. If so, it is still wet inside and more action needs to be taken. Dampness will rust valve gear completely to crap if left in that condition.
Water in generators paid for the construction of my boat, so you want to handle this carefully!!