what in flight temps?
You probably point an IR gun at the cool front of the cooling ribs, whilst the engine has cooled down during idle. If you want to measure, you need a probe, fixed to the back of, and snug up against the cylinder in topmost location. Then you also need to shield the sensor from the cool airflow.
Do not be surprised if you measure 200°C or even more. Temps below 160°C are safe. Below 140° is best, measured during flight, not after.