Engine Temps are depend on may factors, mainly what is the ambient temperature and how hard you work the engine/sticks. If one just strolls around on a 90F day, you can see temperatures on the back plate of 105F and the back side of the head (bottom of heli) of around 225-230F
If you work it hard, you need to open the needles to not exceed those numbers. You can run cooler, but you may be trowing a bit of fuel away. I prefer the later rather than to squeeze every bit of power.
Some 30% fuels run hotter than other 30% fuels and that is normal. Oil formulation and viscosities attribute the diferences.
On a cooler day you will see 5 to 10 degrees less on the head.Take this info with a grain of salt
and always pay good attention to the engine exhaust note and how smooth the engine runs.
The OS/ALign 91 HZ CAN
run smooth while lean and be slowly desintegrating without you noticing. No engine ever self destructs running on the rich side of tunning.