Got my son a Volcano EPX about a month ago. Everything was working good until we started trying to mod it. I'm a little bummed to learn that I can't change out the 64T spur, but i'll get over it. I did some research on the ESC and the manual I found for it states that it will handle down to a 12t motor. The lowest I put in it was a 17t and the ESC got smokin hot. It actually started to get that burning electronics smell. So I dropped down to a Modified 27t and it was still hot. Both motors I used the stock 17t pinion.Put the stock 540 back in and it's fine now. My son wants more torque and speed, but i'm having a hard time finding a good combination of pinion and motor without frying the ESC. The other problem is that the hub carriers on the front have the stupid bushings in them. When I tighten the wheel nut, it binds up and wont let the wheel spin freely. If I loosen it just a bit, the wheel spins freely, but the wheel nut also falls off. I have bearings on my Tamiya and can tighten the wheel nut very tight and not have problems. Will this problem be fixed if I put bearings on the Volcano, and if so, is that a hop-up option for these and what is the part number from Redcat? I'll be in Phoenix next week and plan on stopping by the Redcat shop for some assistance. Thanks for the help.