Well after seeing the video, disregard my comment about the rotary valve, I think it looks ok, doesn’t look like any grooves in it. I can’t really see the milkshake your referring to, the colour of the connecting rods looks kind of whiteish. I’m not overly familiar with what I’m looking at, pretty sure those are the connecting rods. If there is a milkshake of water and oil in there, then I would guess that it’s either ingested water or has been towed and water entered through the exhaust ports. I have no experience with cranks, just always been fortunate enough that I’ve never had to change one. I would get an oil can and squirt injection oil on everything you can see through the intake ports? And then roll it over again with plugs out. Just an idea, I like to I squirt injection oil on everything when I get a new to me ski if I’m not going to be able to work on it for awhile. It’s possible that water had been sitting in there for quite some time and possibly bearings are already damaged. If you take the plugs out and roll the engine over by hand have a look through intake ports and a listen. How does it look and sound? How much liquid did you have come out of that one cylinder?
