from 200 to 250 is a decent temp, it really depends on how how your running and the outside temp. If you dont have a temp gun, you can use the spit method, put some spit on your finger and wipe the top of the cooling head with it, if is sizzles right away your too hot, if it evaporates in 3 to 5 seconds your good and if it just sits there, its too cool.

just make sure no matter what you do, you have plenty of smoke coming from the exhaust.