Zip Zap Motor makes Car "Stutter"

[MST3KPIMP]

I installed the red Turbo Motor from the ZZ Fast & furious kit and now my Z-car stutters.. It used to just stutter around the fridge and at long distances but now it will start zoneing out at 4 feet in all directions. I tried switching pinion gears and tried different gear ratios but with no change. Of course when I put the origional 2.2 motor back in all is fine again. Is there some known issue with the ZZ motors? I filed down the bump at the end so it would fit properly.. I also tried putting in a bit of foil in the contact area thinking it might not be getting proper contact but to no avail. Are the motors slightly different in size? Is it a postion issue? too loose or tight? Thanks in advance

[binaryterror]

Could be an electrical noise issue as well. On larger size RC's the motos can cause this and steering problems, you would then add capacitors to quiet the noise. However i think in a ZZ/Bit car you would be best off to remove the "bad" motor and use a better suited motor.

[MST3KPIMP]

Well I went ahead and installed the NOS motor to see what would happen and to my suprise it works great. None of the bizzare signal loss and the increased speed makes this my motor of choice for now. But it still puzzles me why the red turbo motor would give me so much trouble whereas the more intense NOS does'nt.