this talks about rich and lean temps
i was trying to find this article that mentions a book. In the article it talks about going past 12.3:1 to cool the engine with extra fuel but in fact that doesn't work. idk. Hopefully all you did was a jet change and didn't mess with anything else to get your temp reading. Change one thing then test and repeat, sucks not to be able to change a bunch of stuff at once sometimes but that's what you gotta do to learn.