What KV is your motor again?
I ran out at The Farm2 this past weekend,which is one of the biggest tracks around.
After 10 minutes of hard running track time I was coming off at about 140 degrees on the motor and about 124 was the highest I saw on the speed control.
My motor is a Neu 1512/2/D/F with a MMMv3 and a 12t pinion. It's an awesome combo.
I might get less wheel spin with a larger pinion but the temps are perfect.