[ILLusion]

I saw the article earlier.
It basically issued out a warning about the ball bearing that pushes against the motors armature, which leads to burned out motors. If your gun comes with a non-adjustable motor, you're NOT suppose to use the ball bearing, even though it still comes with SCKs.

There is an on-going issue because some Systema factory assembled guns came with the bearing installed and caused some motors to fry prematurely. Systema USA is awaiting response from Systema Japan as to WHY the bearings are still being installed, and whether users with prematurely damaged motors will be compensated.

I received my factory assembled M4A1 MAX July of 2007 on a preorder from 007airsoft. How do I know if the motor it came with is adjustable or not? It came with the ball bearing installed. Since day one, I have found the action to be a bit on the noisy/"grindy" side. I never minded it too much, since the action is so fast that it doesn't really drag on. To me, it always sounded like how a regular AEG sounds with the motor adjusted on the "too tight" side.
Thankfully, I've put less than 2000 rounds in the gun so far - in the event my ball bearing is incorrectly installed, damage is minimal.