Actual temp numbers for FXR ?

[r34sklnnsn]

Any body know what the temp numbers are for a smooth running FXR ? I have mine in the scx10 receiver case and my Transmitter setup to keep a eye on the temp . She was at 139 degrees while the outside temp was 78 . The hotter the summer gets I'm sure it will go up and I don't want to burn it up .

FX-R ( no ext. bec )
Axial 27t
Dx3s
HS-645mg servo
Stock drive train
mudslinger tires