The Echo CS440 is not the same engine that the BME 44 is. You need the Echo CS 4400 for that. The CS440 has a two piece crankcase and one piece jug. The CS4400 is like the Poulans in that it is a two piece engine. Here are the pics.

If you want an easy and cheap conversion that makes good power try the Poulan 46 or Homelite 45. Both have lots of info about them on here and you can get them from small engine shops for little to nothing. There are several guys who make the needed conversion parts at a reasonable price as well. I just did a Poulan and I have a total of $58 in it and that includes the Hangar 9 mount.