Is there a way to tell blender's automatic weight not to use more then 4 bones per...

Is there a way to tell blender’s automatic weight not to use more then 4 bones per vertex?
I need to import my model to Unity3D and it supports up to 4 bones per vertex.
I really like the blender’s automatic weight results but it uses too many bones per vertex, even when i remove some bones, it will go ahead and use other farther bones.
I found a plugin named weightloss, it is canceling influences from more then 4 bones per vertex, however, it screw the rigging ( it give me the same results as unity but without having to export it ).