Shuriken particle system mesh question

Basically I want to do spaceship engine effects and I created a mesh for that in Blender, but when I put it into the mesh section of the particle, emitter emits nothing. It shows with basic stuff like cubes or cyclinders but I couldnt get it to work with my own mesh.

Anyone know what's causing the problem? Also is there a documentation of how meshes should be to use in the new particle system?

Thanks.