Dark Impact gearing

[tobbe]

Hi!
Just got my Dark Impact. First I used a Nosram Vision 14x2 turn motor with the stock pinion (26T) and a 81T spurgear with the slipper clutch. But the motor got extremely hot just after a few minutes. The acceleration was also sloooooow...So I changed to the stock motor to drive with. Now the motor temp. is OK but the topspeed is pretty slow. The Vision 14x2 motor also doesn't work quite well anymore. I think it overheated a few times . So I'm going to buy a new motor. Probably a Nosram Vision 17x2 or a 19x2 turn. But wich size spurgear and pinion should I use to avoid overheating and destroying the motor?