Hi Myring

Idle is often when the EGT is highest, but your temps are too high. If you can notice any hot spots on the tail cone at idle , then I would suggest that you may have an uneven burn problem, either to do with the combustion chamber or a blocked fule manifold (more likely).

I have seen blocked fuel manifolds cause engines push the flame out of the exhaust and the needles on the JJ-1200 are only 24g so any small amount of dirt or flux from the soldering process could be blocking one or more needles.

Good luck.