Pisser changes as engine warms

[tor*p*do]

I noticed that the pisser coming off the head (dual cooled, 2 pissers) becomes foamy once the motor warms up.
Cannot get the motor tuned, maybe a water jacket leak?
Seems to be running on one cylinder but both plugs are hot to the touch.
Any ideas?

 

[restosud]

sounds like a head gasket or cylinder leak in there somewhere.time to open it up.