Animating a self-created animation with Mecanim properly.

I have a character rigged and animating using Unity’s mecanim system. If I create an animation (like a sword swing), is it a good idea to use that animation with Mecanim? I created a simple hands up animation where my character lifts their hands up, but when I try to use it with mecanim (with loop pose enabled), the animation doesn’t look right (the hands don’t come up all the way, so it looks like he is just rotating his arms in small circles). Any ideas on how to fix this?

Totally new to animations and Mecanim but since threads in this forum don;t seam to get answered I will go ahead and take a guess.
Is your animation itself looped correctly before you imported into Unity? I mean is last frame matching first? If not then applying loop in Mecanim would probably produce some crazy results.

Make sure your rig is configured correctly. In the FBX inspector, on the Rig tab, click on Configure.... Verify that the skeleton is mapped the way you expect.