[RC-Monster Mike]

I thought you had a buggy for some reason, which is why I suggested a 16t pinion - 12/46 on a buggy would be undergeared, but on a truggy it may be the opposite, considereing the buggy ratio diffs. Using the stock spur, a 16t pinion is about the sweet spot for a 4s 9xl motor (buggy or truggy usually).
I would agree with the pimp on this one. The gearing isn't too far off at all for a truggy with buggy diffs - perhaps slightly overgeared if anything, but it sounds just about right. 5s and truggy diffs would likely reduce motor heat for this. The 9xl ran pretty hot in my Losi 8t - after dumping a 5000mah 4s pack, it was typically around 180F or so. This is kind of the nature of the lower end motors - for cool temps under hard abuse, a Neu motor is the answer. Fans would also help the cause - cheap insurance IMO. :)