Like Randy said... my deck and blade were way off too. The instructions tell you to adjust the air pressure, once you do that- park the mower on a level surface and get yourself a short ruler and do an accurate measurement of the blade heights (left/right & front/back) just like the instructions say. Once I did that and got the blades level, then adjusted the anti-scalping wheels since they too were off. After all that.... finally, it worked. Good luck.