I have twin F150XA Motors. I replaced the water pumps last weekend and now have water blowing out (at 600 RPM idle) on the port motor. This is the upper exhaust above the water line(1"x3" black plastic). I had a 38 mile run home after i noticed it and the motor ran flawless. No heating problems. Motor pee'ed strong as did the starboard. This is only happenning at Idle. Once in gear, it drasticly slows, then stops at anything above 800 RPM's. I replaced thermostats 4 months ago. I checked the Port motor popper valve (Small plastic stopper with spring) and the thermostat-all looks good. Motors have 570 hrs. This is the counter Rotation motor- not sure if this has anything to do with it.