That's too hot in my opinion.

I like to run mine at 160F plus the ambient temperature.

However I use temperature as a secondary measure. I tune on sound, feel and ensuring smoke out of the corners. I also look at the plug element as that's a really good way to check your tune is good. As a rule of thumb if you are getting good smoke out of the corners and the engine isn't running on after WOT then you aren't lean.