Is it still overheating three turns out and did you cut cooling holes in the windshield back window and side window? You want to keep the temp around 270 or less and the lowspeed needle needs to be leaned out a little bit (1/8th turn at a time). My high speed screw is about 3 and 1/4 turns out.
On the gear mesh take two 1/4' wide by 3" long pieces of notebook paper fold them in half place between the gears and the clutch bell gears and press firmly together and tighten the screws. It sounds like the clutch bell isn't spuare with the gears.
I use 20% O'Donnel RTR fuel which is one of the fuels CEN recomends.

Hope this helps.