I don't know exactly whats wrong with yours but I do know that if it's anything like the 218 we have you should be able to cut close.Generally we like to cut close enough that you can not tell which direction it had been planted.Make sure as other post said that it is clean under neath,crap can pack in awful hard,make sure header control is not keeping it up,shut off control and cut manually see if it cuts lower when dropped hard on the ground.A few years ago when beans were very short we did all of them with head hard on the ground,used up a set of poly but got all the beans. It is able to cut close,something is keeping it from working.