Having a problem with milky foam coming out of the breather. The oil on the dipstick looks fine. Found this problem last Sat, changed the oil, and cleaned the breathers and the hose attached, took the boat out and the milk is still back. Engine runs great, it does not skip, run or idle rough, top speed is still the same. Water temp around 160 and goes to the ocasional 180. Oil pressure is 40 and above off idle, 25 - 30 on idle. This is a stock 502 with mercruiser exhaust and risers to thru hull exhaust. Took the risers off to see if there is any evidence of reversion, riser looks fine in the center gray exhaust, though rusty in the other water jackets. The gaskets did look rusted and beat. The water I was running in was pretty cold, I would say in the 50s. Could this also be a case of condensation? Any ideas would be much appreciated.