hvac snap switch hi limit manual reset for hi temp?

I was thinking..some here wanted a temp alarm or equivalent on ob's that have none. I have used them for steam boiler protection in the past and while sitting on the potty thought why not on ob's. Close on rise with manual reset, say 200F or so in parallel with stop switch. But that may be dangerous to cut power all at once without notice?

How else might this snap switch might be usable...battary pack maybe to run a light?

Definitely dangerous to cut power all at once. Hope you have a great personal liability lawyer at your disposal ! Imagine someone standing up at wot in a boat and losing power.......
Better to just activate a good loud horn.

i wouldnt recommend cutting power. wire it to an alarm of some sort. heck what if you were standing while driving and it shut down.

Could end up like the time when my GF and I were running up river in sort of an emergency situation (trying to get someone to run back down there with a barge to pick up a stranded boater). My motor died. SHe was sitting in the front of the boat up on the pedstal, told her to sit down on the deck but no. Motor died, she goes right over the front of the boat in ICE cold (like 43°F) water. Luckily it was only about waist deep but still.....

The Yamaha's have a RPM limit. When engine temp gets to a certain point, the engine goes into limp mode rather than cutting spark totally. It gets your attention but it's not enough to create a panic type situation.

The other issue with cutting power totally is restarting. Once the motor is shut off, it gets even hotter for a minute or two after being shut down. If you had to restart quickly, you'd need a manual over-ride of some sort which adds more complexity.

Kill top cylinder