Could you please take a photo of the motors that your tank is using?
No matter what motors you use, if the problem is in bad calibrated electronics, you wont stop super spinning... So first of all, we must address the problem. If you have the kit 56010, it comes already with good gearboxes and you should not be doing super spins.
Of course the gear downs are cool, and the ETO gearboxes are nuke proof, but problarbly you wont need to replace your stock ones.