Autonomous Robot, motor driver

HazardsMind:
You should add a small delay in there to see the change. Also for that particular segment, I would swap analogWrite(PWML, speed), with analogWrite(PWML, i);//

I just tried it, worked in the Air, again put it on the carpet and it stalled.

Attached are the pictures of my bot. Did I install the motors the wrong way? Should the motor and bracket be above the chassis?

WHY THE STALL! lol its getting frustrating