Need help identifing water leak problem

[Jhamme4]

I have a 1985 two stroke 50HP Yamaha outboard with a Jet. The motor runs great, however, at high RPMs, water pours in a steady stream from the drain holes in the back of the cowling. I have pulled the spark plugs and everything appears normal. At low RPMs, (idle) the tell-tell stream is weak. At high RPMs, it is strong. I have ran the motor with the cover off but am unable to figure out exactly where it is coming from. It seems to be coming from the bottom of the head. Oily residue remains on the bottom of the cowling after each use but I don't know if it is a byproduct of my problem or just left over from past oil spills. Before I start tearing apart, I thought I would ask and see if someone has had this problem or could point me in the right direction.