The problem that you are probably experiencing is the donation of hashes issue. After 400 hashes, yam will stop mining because it is unable to connect to the hard coded pool and contribute hashes for donation to the author yvg1900. This is a forever problem because the hard coded pool no longer exists. Until we get a new pool up and yvg1900 updates his software, we are stuck with making our own workarounds.

To get around this, you will need to do different things depending on whether you have Linux, Windows, or Macintosh. Regardless of system type, you need to set yam to restart every so often before you reach 400 hashes.  The amount of time you need is based on the HPM of your CPU and can be found if you divide 400 hashes by your HPM.