got a tornado BB and it runs real well if i dont stay on the throttle for awhile. like when i go through the grass it will stay in first and be at high rpm and starts to bogg down after that and lose of power... im thinking its over heating it also does this is when i do alot of donuts in the gravel.. it has a smoke stream coming out but may not enough what do u guys think...before i messed with the tuning it would have gas spitting out the exsaust when....not alot but a good amount