1. Dont tune by temp but watch ur temp, Im not sure what the losi engine runs at but tune where its got good power band and runs the way u want it.

2.The on-board temp isnt 100% accurate to a temp gun i would just use a temp gun and take off the on-board temp.

3. 300 degrees is way to high for any engine im sure the losi engine should only be around 260 MAX but like i said i dont know the engine at all.