?power surge
 

my slash(4x4) full throttle will surge in straight ahead run and running fine in a turn ive cycled both of my fully charged batters and the same problem repeats on sand or gravel...
ive checked all connections and the motor is not excessively hot with either the heat sink or fan on the motor no difference what gives?? how is this fixed??

I've had a similar issue with the Sky RC brand ESC which would tend to surge full throttle for a brief second and lose control of steering, then normal function would return... this wasn't a big deal until my car lost control and ran into someone's shin at the track. I simply switched brands of ESC and never went back to Sky RC again.