Re: running without a t-stat

[wiscoboater]

Many times when these old motors are put away "wet" and forgotten for years the water trapped within can corrode and form calcium deposits within the water jacket. When fired up again years later the scale formed from the water, or just condensation from the water sitting for years can come loose in flakes…or layers, and wreak havoc in the small water passages. Spending many years working on classic cars, I have seen this many times. The hard calcified flakes can clog all but the biggest passages. It transcends to old outboard motors as well.
Don’t know if this is your issue but it is good food for thought.