I just got my new tiller. It is a 6' Agric. The manual was not with and they are going to send me one but I want to use it in the meantime. I got it all connected and tilled up a small patch of land today and it did fine but I was not really sure how to adjust the back gate with the chain. I played with it a little bit but I did not really see what it was doing. It also is adjustable for the depth but I was not sure where to set it. As long is it is running fine the deeper the better?