Ok, so i had this running just a few days ago, but then when i tried to assamble it didnt work out for me. Now I cant even get this simple DC motor running from the arduino, or to be more precise; the motor will run at a very low speed. Connecting it directly to my two 1.5 batteries it will run at full speed, but when trying to control it from the Arduino it wont work for me.
Here is my setup:

and the code is dead simple: