Are you running these engines long enough to get them hot enough to boil the combustion byproduct water out of the oil? Water is the result of burning gasoline in the presence of oxygen . . . .
Rick
What I came up with:
The one that has been sitting in my yard -- I think this might be it. It hasn't been ran to temp since the rebuild except maybe once or twice. It has a slight green tint to the oil -- not really milky. I'm going to swap the automotive oil out of it anyway for some atv oil -- and will just keep an eye on it until I know for sure I have a problem.
The other one -- everything in the front cover seemed normal. The rear output shaft seal is leaking(not enough to put oil on the ground -- but enough to see it on the case -- and the front cover is leaking a little in the spot where a previous disassembler had used a screwdriver to pry(leaking about the same amount). Also had a little water in the bottom of the airbox -- so obviously the guy didn't have it sealed up perfectly -- and I'm guessing 95% of the water issue was the airbox water getting to the crankcase breather.
I replaced both front and rear output seals -- water pump mechanical seal -- and water pump oil seal. Also jabbed on some hardening silicone in the spots that had gashes in the case -- and sealed it up good. We will see on everything tomorrow.
Think I may have overreacted and/or had under confidence in myself. Just wasn't any clear mistakes there. At least not on my part.