You need to adjust the control arm going from the servo to the swash plate, if you pull the canopy off and look at the control arms, the one on the right(as if you were sitting in the heli) controls the right and left movements, the left on controls forward and reverse movement. since your drifting left yo need to adjust the right control arm. to do this pop the arm off the swash plate( a ball link tool is handy for doing this) and in your case shorten the length of the arm, do half turns at a time. most important while doing these adjustments is have the tramsmitter on and the heli powered up and the trims in the center. keeping trims centered, take off and see what the heli does, if it still drifts the readjust control arms until desired control is achieved. you will always have to adjust the trims alittle(while flying). for testing purposes you can fly the heli with canopy off(while making adjustments), but never attempt to fly with tail off. get use to making adjustments, because if you install the aluminum upgrades to will need to readjust the arms again. once you take the time to make a few minor adjustments you heli will give you hours of enjoyment.

And make sure when you plug the battery in, the heli is on a level surface. if this isnt done the gyro will not be centered and the heli will drift and fly funny(could be part of your problem).

I did have a motor go bad, so you might want to order a spare set, but that was after many hours of flying(I have three batterys, so I fly alot).

Glad to help, feel free to ask if you need more help,
Dennis