2002 Grizzly 660. Water in oil. Drained it all, very nasty - almost like tan paint. Flushed it a few times.... still nasty
Never been in any water over 6" so it was not from sinking it or running in water too deep.
I started looking at everything on the cooling system since it was apparent the coolant/water for the radiator was getting in the oil.
Water pump is new (I had a spare new one from another Grizzly so I put it on) - no leaking - no weep hole leaking, etc...
Radiator would not stay full.
I put in a new Tstat since the old one was stuck open after inspection. I then decided, and I know this is a rookie move/test, but I poured water in the inlet to the motor where the Tstat sits and the water started draining out the oil drain plug. Not quickly, but after about 2 - 3 minutes, it started a very small stream of water/oil mix (mostly water). Then, with the oil filter off and the spark plug unplugged - I turned the motor and water poured out of the oil filter area.

So, I have a gasket, cylinder, head, etc... problems. I am fairly mechanically inclined and have a manual. Anyone have any ideas on what has failed? Is it very difficult to take off and rebuild the top end?

Funny thing is, the thing ran great, no smoke at all, lots of torque,..... until it overheated and I shut it off.

Thanks
Steve

 

Sounds like your head gasket blew for some reason Top ends are not that bad to do. be careful pulling it apart when you do and inspect the gaskets That will tell you what happened. Take lots of pictures and I bet there is a youtube video on it. I would recommend flushing the case with diesel fuel to dry it up in there after the top end is off and you do your inspection.