It's all so HOT!!!

Hello! I'm new to the sight and real happy to be here...

I have an ERevo that I have been trying to race but I have been pretty unsuccessfull lately due to my motor overheating. I was hoping that someone could tell me if there is a simple reason in my set up that is causing the problem. It's kind of odd because I didn't have any trouble when I first got this revo. I even got second in a club race last Spring. The last couple of times I tried to race, however, the system went into thermal shut down (I think) about 14 minutes into the mains when the motor hit 180 degrees.

So anyway the set up is as follows:

Basically stock Erevo
HVMax 6.5 combo (Motor and ESC)
68 T spur
16T Pinion (down from the 19)
Running on the Responce pin tires with the 3.8 dish wheels

I'm runnin 2 -10,000 mah 10C 2S2P lipos from TrueRC

I have been through the drive train to check for binding. I have the novak heat sink on the motor but I have never used any thermal grease and have some on order. I also have a 14T and 12T pinion comin to see what they will do for me. I read on another thread that 16T is the biggest pinion you can run with the 68 spur so I ordered the smaller pinions. So anyway I would appreciate all the advice I can get.

I really like racing the revo and making the switch from nitro to electric was really enjoyable till I started having these problems. I have had plenty of people tell me that I should trash the Novak system and get the MMM but I only know one guy personally that runs mamba equipment and he's had his share of problems as well. Plus I really don't have the money to throw at a new brushless set up right now.

Oh yeah... Sorry for the long post!