Try the 62t spur, but that will give you maybe 30mph, and the 8xl should be good for 40 mph. This may help with the heat, but I think that you are at full throttle most of the time with your current gearing. The temps of the esc and batteries seem to support this theory. The feigao motors do not run cool but with proper gearing they are usable and are a super performer for the price!
I would say to buy a 23t pinion, then with the 62, 65, 68t spurs you would have 38, 36, 34mph respectively. That is a decent range of speed to expect from the 8xl. You could also buy a 22 and 24t pinion, that would open up more gearing options.
The heatsink is also a good idea, if only to help hold the motor together.
thanks lincpimp i will try that out when monster gets some more , they are out right now,thats not the first time youve helped me out,thanks
No prob man, hope that helps the problem. I can only think that the 8xl is just spinning too hard with the low gearing. It is always good to have extra gears, I must have at least 2 doz pinions in my tray. And the ones on the vehicles!