question about 2 strokes

[Wpg Manitoba]

I have 2 pull start water cooled outboards, one a 25hp yamaha and 3.6hp parson. My question is if the water pump seizes and you don't notice is there a safety overheat shutoff? Or does it keep going untill it breaks down from over heating?

[boats.net]

If the 25 Yamaha is oil injected or four stroke model then it will have a rpm reduction if overheats, it will drop to 2000 rpm's.

Overheat

I have a 25hp 3cyl, if it overheats it will run really rough and the rpm's will cut back dramatically.