Lou, Thank you.
First off, I removed the thermostat housing, which is a PITA on my boat as there are wiring looms (EFI) that rest around it. But, I got the plug off the front of the intake manifold and guess how much water came out? NONE, zero. I looked into the intake manifold through the thermostat housing and it was mostly dry
Lol. Just my luck anyways..... on the bright side, the thermostat bolts were a bear to remove, they are all rusty. At the very least, this allows me to clean them up, and apply some never seize onto them.
I poured about 1/2 gallon of -100 through the big fat hose going to the water pump (the automotive style one, NOT the one with the impeller inside), and it came out of my block drains. I then did my usual of pouring some antifreeze back through the water hose that comes in from the outdrive, which includes my power steering cooler. So I am declaring my port engine done.
Going to finish my starboard engine in my garage - it is being pulled next week so that I can also pull my Kohler generator, which stopped producing power this season. $$$$$$ That engine has already been completely drained of water. Im not going to bother with the intake manifold plug, seeing the results on my port engine.
Anyway, just a reminder to those of us with fuel coolers, to make sure to clear those of water too. I use compressed air to blow them out every year. I generally have an OCD routine of my own that i do every year, but this year I am too busy and appreciate any easier methods than what i do (Which is remove every single hose and plug, flush with -100f antifreeze, and blow out my water heater heat exchanger, PS cooler, and fuel cooler. Never had a problem in 7 seasons with this boat, thank god!