I am running the HW XR8 plus G2 and the G3 4274 2250Kv. Went with the plus as it had all the same features and the newer fan design. Running a 15t pinion with stock plastic spur gear, and a cheap-o dual 40mm fan setup on the motor. Ambient was 75 degree F. 6 min run with lots of full throttle and highest recorded was 145 F for the motor. See attached chart for Temps. Brown line is motor temp. Also, recorded top speed of 48 mph. I will probably add timing instead of going up a tooth size since I have temp room to play with.