feiago 8xl getting hot in emaxx

[nitrorube]

ok guys i need some help,im running a mamba max,feigao 8xl,4cell lipo and the motor is getting hot,like 170 with temp gun.my question is im running a 18 pinion and i have all three spur gears 62,65 and 68,how can i get temps down,is my gearing off?do i need a new pinion.i tried the 65 and 68 and the motor still gets hot,i have made a cooling hole in body and i will order the rc monster heatsink which they are out of,anything else?esc is warm but fine and batteries are cool