Ive never owned an engine that doesn't spray water out strongly even when cold using engine muffs, yes they spray it out harder when the thermostat opens but it should still be pumping water out when cold.
If the heavy fishing line up the pee hole doesn't work you could run a concentrated wash of saltaway through etc. Ive heard some people use a diluted solution with vinegar.
How old is the impeller, you don't need the engine to run long without water pumping through to do damage to them and should be replaced every 100hrs or once a year.
Jon
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