Which drive system does it have (Electronize, 4QD, Armortek silver box) ?
Which RC system do you use (Futaba 6EX, 7C, Spectrum) ?
How is the receiver powered (battery, BEC, Armortek PSU) ?
It sounds like the receiver is losing connection with the transmitter and the in-built "fail safe"system is cutting in. On an 'plane, this cuts the throttle but on a tank it puts one track in reverse, hence spinning the tank on the spot.
[Sd.Kfz 222] [Sd.Kfz 7] [Flak 36] [PzKpfw III] [Stug III] [PzKpfw IV] [PzKpfw VI Early] [PzKpfw VI Mid]
[Sherman BARV] [Sherman M4A3] [Sherman Firefly VC] [M2 Halftrack] [M3 Halftack]