Receiver w/ 4 ohm speakers
If you have an all axiom setup and the M80s are the only 4 ohm speakers then you will probably be fine. Just make sure the receiver is well ventelated.
If you have a huge room, listen at extremently high levels, or leave the receiver running all day long, then you might run into a problem with the receiver going into shutdown.
I would also check on the Axiom forum for feedback from owners with this speaker / receiver combo. The Axiom speakers and the Yamaha have the makings for a great HT.