You'll know if you're overheating the engine. Smoke will come off of it and it will smell like cooked oil. You have to really over-lean this engine before you can hurt it. Adjust it by ear to peak RPM and then back it off a few clicks. The best way to do it is with the airplane pointed straight up. That is the condition in which it is hardest for the engine to draw fuel. When the airplane is level the engine will richen a little bit and all will be well.