You might think this is crazy, but if you have no success in breaking him to poop outside you can try this as a last resort. Take a Q-tip and break it about in half. Then when you get him out of the crate just pop the cotton end in his rectum about 3/4 inch. When you put him on the ground he will crap real soon so be ready to put him outside. It might take a few times to break him, but it will work.