67 evinrude 80hp head temp. switch?

[a70eliminator]

I wanted to verify the temp switch is working properly, I removed the switch, got my ohm meter, jumpers, thermometer, and a pan of water on the stove, I noticed a part number and right below that 260F. Put it a pan and brought the water to boiling and the switch didn't close, I took a bic lighter and waved the switch above the flame and now snaps close and back open when cooled a little, why on earth would they put a 260 switch in there? possibly to mask another problem somewhere back in it's 40yr history. what I don't get is why there was even a switch of this temp available, it appears to be a unique set up, it's not like someone could have went to the local appliance store for a clothes dryer limit switch.
This temp alarm seems totally worthless, the engine would burn up stall before the warning buzzer would go off I think?