[chike87]

I am replacing a piston in my Yamaha, got the engine broke down and noticed oil or oil and water mixture in bottom of crankcase. Should there liquid in there? Thanks.

 

[GCwaverunner]

Its ok if there's only a little bit. Usually some drops down there when removing the barrel. Just check the crank doesn't have any rust on it and the big end bearing is still good.